1
|
Hour C, Chuon K, Song MC, Shim JG, Cho SG, Kang KW, Kim JH, Jung KH. Unveiling the critical role of K + for xanthorhodopsin expression in E. coli. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 258:112976. [PMID: 39002191 DOI: 10.1016/j.jphotobiol.2024.112976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 06/19/2024] [Accepted: 07/01/2024] [Indexed: 07/15/2024]
Abstract
Xanthorhodopsin (XR), a retinal-binding 7-transmembrane protein isolated from the eubacterium Salinibacter ruber, utilizes two chromophores (retinal and salinixanthin (SAL)) as an outward proton pump and energy-donating carotenoid. However, research on XR has been impeded owing to limitations in achieving heterogeneous expression of stable forms and high production levels of both wild-type and mutants. We successfully expressed wild-type and mutant XRs in Escherichia coli in the presence of K+. Achieving XR expression requires significant K+ and a low inducer concentration. In particular, we highlight the significance of Ser-159 in helix E located near Gly-156 (a carotenoid-binding position) as a critical site for XR expression. Our findings indicate that replacing Ser-159 with a smaller amino acid, alanine, can enhance XR expression in a manner comparable to K+, implying that Ser-159 poses a steric hindrance for pigment formation in XR. In the presence of K+, the proton pumping and photocycle of the wild-type and mutants were characterized and compared; the wild-type result suggests similar properties to the first reported XR isolation from the S. ruber membrane fraction. We propose that the K+ gradient across the cell membrane of S. ruber serves to uphold the membrane potential of the organism and plays a role in the expression of proteins, such as XR, as demonstrated in our study. Our findings deepen the understanding of adaptive protein expression, particularly in halophilic organisms. We highlight salt selection as a promising strategy for improving protein yield and functionality.
Collapse
Affiliation(s)
- Chenda Hour
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Kimleng Chuon
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Myung-Chul Song
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Jin-Gon Shim
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Shin-Gyu Cho
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea; Research Institute for Basic Science, Sogang University, Seoul, Republic of Korea
| | - Kun-Wook Kang
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Ji-Hyun Kim
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Kwang-Hwan Jung
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea.
| |
Collapse
|
2
|
Gorriti MF, Bamann C, Alonso-Reyes DG, Wood P, Bamberg E, Farías ME, Gärtner W, Albarracín VH. Functional characterization of xanthorhodopsin in Salinivibrio socompensis, a novel halophile isolated from modern stromatolites. Photochem Photobiol Sci 2023; 22:1809-1823. [PMID: 37036621 DOI: 10.1007/s43630-023-00412-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/21/2023] [Indexed: 04/11/2023]
Abstract
A putative xanthorhodopsin-encoding gene, XR34, was found in the genome of the moderately halophilic gammaproteobacterium Salinivibrio socompensis S34, isolated from modern stromatolites found on the shore of Laguna Socompa (3570 m), Argentina Puna. XR-encoding genes were clustered together with genes encoding X-carotene, retinal (vitamin-A aldehyde), and carotenoid biosynthesis enzymes while the carotene ketolase gene critical for the salinixanthin antenna compound was absent. To identify its functional behavior, we herein overexpressed and characterized this intriguing microbial rhodopsin. Recombinant XR34 showed all the salient features of canonical microbial rhodopsin and covalently bound retinal as a functional chromophore with λmax = 561 nm (εmax ca. 60,000 M-1 cm-1). Two canonical counterions with pK values of around 6 and 3 were identified by pH titration of the recombinant protein. With a recovery time of approximately half an hour in the dark, XR34 shows light-dark adaptation shifting the absorption maximum from 551 to 561 nm. Laser-flash induced photochemistry at pH 9 (deprotonated primary counterion) identified a photocycle starting with a K-like intermediate, followed by an M-state (λmax ca. 400 nm, deprotonated Schiff base), and a final long wavelength-absorbing N- or O-like intermediate before returning to the parental 561 nm-state. Initiating the photocycle at pH 5 (protonated counterion) yields only bathochromic intermediates, due to the lacking capacity of the counterion to accept the Schiff base proton. Illumination of the membrane-embedded protein yielded a capacitive transport current. The presence of the M-intermediate under these conditions was demonstrated by a blue light-induced shunt process.
Collapse
Affiliation(s)
- Marta F Gorriti
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, Av. Belgrano y Pje. Caseros, San Miguel de Tucumán, 4000, Tucumán, Argentina
| | - Christian Bamann
- Max-Planck-Institute for Biophysics, Max-von-Laue-Straße 3, Frankfurt am Main, 60438, Germany
| | - Daniel Gonzalo Alonso-Reyes
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME, CONICET, UNT) CCT, CONICET, Facultad de Agronomía, Zootecnia y Veterinaria, Finca El Manantial, UNT, Camino de Sirga s/n (4107), Yerba Buena, Tucumán, Argentina
- Institute for Analytical Chemistry, University of Leipzig, Johannisallee 29, Leipzig, 04103, Germany
| | - Phillip Wood
- Max-Planck-Institute for Biophysics, Max-von-Laue-Straße 3, Frankfurt am Main, 60438, Germany
| | - Ernst Bamberg
- Max-Planck-Institute for Biophysics, Max-von-Laue-Straße 3, Frankfurt am Main, 60438, Germany
| | - María Eugenia Farías
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, Av. Belgrano y Pje. Caseros, San Miguel de Tucumán, 4000, Tucumán, Argentina
| | - Wolfgang Gärtner
- Institute for Analytical Chemistry, University of Leipzig, Johannisallee 29, Leipzig, 04103, Germany
| | - Virginia Helena Albarracín
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME, CONICET, UNT) CCT, CONICET, Facultad de Agronomía, Zootecnia y Veterinaria, Finca El Manantial, UNT, Camino de Sirga s/n (4107), Yerba Buena, Tucumán, Argentina.
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Miguel Lillo 205, San Miguel de Tucumán, 4000, Tucumán, Argentina.
- Facultad de Agronomía, Zootecnia y Veterinaria, Universidad Nacional de Tucumán, Centro Universitario Ing. R. Herrera (Ex Quinta Agronómica), Avda. Pte. N. Kirchner 1900., San Miguel de Tucumán, 4000, Tucumán, Argentina.
| |
Collapse
|
3
|
Bar-Shalom R, Rozenberg A, Lahyani M, Hassanzadeh B, Sahoo G, Haber M, Burgsdorf I, Tang X, Squatrito V, Gomez-Consarnau L, Béjà O, Steindler L. Rhodopsin-mediated nutrient uptake by cultivated photoheterotrophic Verrucomicrobiota. THE ISME JOURNAL 2023:10.1038/s41396-023-01412-1. [PMID: 37120702 DOI: 10.1038/s41396-023-01412-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/31/2023] [Accepted: 04/05/2023] [Indexed: 05/01/2023]
Abstract
Rhodopsin photosystems convert light energy into electrochemical gradients used by the cell to produce ATP, or for other energy-demanding processes. While these photosystems are widespread in the ocean and have been identified in diverse microbial taxonomic groups, their physiological role in vivo has only been studied in few marine bacterial strains. Recent metagenomic studies revealed the presence of rhodopsin genes in the understudied Verrucomicrobiota phylum, yet their distribution within different Verrucomicrobiota lineages, their diversity, and function remain unknown. In this study, we show that more than 7% of Verrucomicrobiota genomes (n = 2916) harbor rhodopsins of different types. Furthermore, we describe the first two cultivated rhodopsin-containing strains, one harboring a proteorhodopsin gene and the other a xanthorhodopsin gene, allowing us to characterize their physiology under laboratory-controlled conditions. The strains were isolated in a previous study from the Eastern Mediterranean Sea and read mapping of 16S rRNA gene amplicons showed the highest abundances of these strains at the deep chlorophyll maximum (source of their inoculum) in winter and spring, with a substantial decrease in summer. Genomic analysis of the isolates suggests that motility and degradation of organic material, both energy demanding functions, may be supported by rhodopsin phototrophy in Verrucomicrobiota. Under culture conditions, we show that rhodopsin phototrophy occurs under carbon starvation, with light-mediated energy generation supporting sugar transport into the cells. Overall, this study suggests that photoheterotrophic Verrucomicrobiota may occupy an ecological niche where energy harvested from light enables bacterial motility toward organic matter and supports nutrient uptake.
Collapse
Affiliation(s)
- Rinat Bar-Shalom
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Andrey Rozenberg
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Matan Lahyani
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Babak Hassanzadeh
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Gobardhan Sahoo
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
- Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Puducherry, 605014, India
| | - Markus Haber
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
- Institute of Hydrobiology, Biology Centre CAS, Na Sadkach 7, 37005, Ceske Budejovice, Czechia
| | - Ilia Burgsdorf
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Xinyu Tang
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Valeria Squatrito
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Laura Gomez-Consarnau
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
- Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, BC, México
| | - Oded Béjà
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Laura Steindler
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel.
| |
Collapse
|
4
|
Viver T, Conrad RE, Lucio M, Harir M, Urdiain M, Gago JF, Suárez-Suárez A, Bustos-Caparros E, Sanchez-Martinez R, Mayol E, Fassetta F, Pang J, Mădălin Gridan I, Venter S, Santos F, Baxter B, Llames ME, Cristea A, Banciu HL, Hedlund BP, Stott MB, Kämpfer P, Amann R, Schmitt-Kopplin P, Konstantinidis KT, Rossello-Mora R. Description of two cultivated and two uncultivated new Salinibacter species, one named following the rules of the bacteriological code: Salinibacter grassmerensis sp. nov.; and three named following the rules of the SeqCode: Salinibacter pepae sp. nov., Salinibacter abyssi sp. nov., and Salinibacter pampae sp. nov. Syst Appl Microbiol 2023; 46:126416. [PMID: 36965279 DOI: 10.1016/j.syapm.2023.126416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/17/2023]
Abstract
Current -omics methods allow the collection of a large amount of information that helps in describing the microbial diversity in nature. Here, and as a result of a culturomic approach that rendered the collection of thousands of isolates from 5 different hypersaline sites (in Spain, USA and New Zealand), we obtained 21 strains that represent two new Salinibacter species. For these species we propose the names Salinibacter pepae sp. nov. and Salinibacter grassmerensis sp. nov. (showing average nucleotide identity (ANI) values < 95.09% and 87.08% with Sal. ruber M31T, respectively). Metabolomics revealed species-specific discriminative profiles. Sal. ruber strains were distinguished by a higher percentage of polyunsaturated fatty acids and specific N-functionalized fatty acids; and Sal. altiplanensis was distinguished by an increased number of glycosylated molecules. Based on sequence characteristics and inferred phenotype of metagenome-assembled genomes (MAGs), we describe two new members of the genus Salinibacter. These species dominated in different sites and always coexisted with Sal. ruber and Sal. pepae. Based on the MAGs from three Argentinian lakes in the Pampa region of Argentina and the MAG of the Romanian lake Fără Fund, we describe the species Salinibacter pampae sp. nov. and Salinibacter abyssi sp. nov. respectively (showing ANI values 90.94% and 91.48% with Sal. ruber M31T, respectively). Sal. grassmerensis sp. nov. name was formed according to the rules of the International Code for Nomenclature of Prokaryotes (ICNP), and Sal. pepae, Sal. pampae sp. nov. and Sal. abyssi sp. nov. are proposed following the rules of the newly published Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode). This work constitutes an example on how classification under ICNP and SeqCode can coexist, and how the official naming a cultivated organism for which the deposit in public repositories is difficult finds an intermediate solution.
Collapse
Affiliation(s)
- Tomeu Viver
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Bremen, Germany.
| | - Roth E Conrad
- Ocean Science & Engineering, School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA; School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Marianna Lucio
- Research Unit Analytical BioGeoChemistry, Helmholtz Munich, 85764 Neuherberg, Germany
| | - Mourad Harir
- Research Unit Analytical BioGeoChemistry, Helmholtz Munich, 85764 Neuherberg, Germany; Chair of Analytical Food Chemistry, Technical University Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany
| | - Mercedes Urdiain
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | - Juan F Gago
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | - Ana Suárez-Suárez
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | - Esteban Bustos-Caparros
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain
| | - Rodrigo Sanchez-Martinez
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690, San Vicent del Raspeig, Alicante, Spain
| | - Eva Mayol
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690, San Vicent del Raspeig, Alicante, Spain
| | - Federico Fassetta
- Laboratorio de Ecología Acuática, Instituto Tecnológico Chascomús (INTECH)-CONICET-UNSAM, Escuela de Bio y Nanotecnologías -UNSAM, Buenos Aires, Argentina
| | - Jinfeng Pang
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154-4004, USA
| | - Ionuț Mădălin Gridan
- Doctoral School of Integrative Biology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania
| | - Stephanus Venter
- Department of Biochemistry, Genetics and Microbiology, and Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Fernando Santos
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690, San Vicent del Raspeig, Alicante, Spain
| | - Bonnie Baxter
- Great Salt Lake Institute, Westminster College, Salt Lake City, UT, 84105, USA
| | - María E Llames
- Laboratorio de Ecología Acuática, Instituto Tecnológico Chascomús (INTECH)-CONICET-UNSAM, Escuela de Bio y Nanotecnologías -UNSAM, Buenos Aires, Argentina
| | - Adorján Cristea
- Department of Taxonomy and Ecology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj‑Napoca, Romania
| | - Horia L Banciu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj‑Napoca, Romania; Emil G. Racoviță Institute, Babeș-Bolyai University, Cluj‑Napoca, Romania
| | - Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154-4004, USA
| | - Matthew B Stott
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Peter Kämpfer
- Institute of Applied Microbiology (IFZ), Justus Liebig Universität Giessen, Giessen, Germany
| | - Rudolf Amann
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Munich, 85764 Neuherberg, Germany; Chair of Analytical Food Chemistry, Technical University Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany
| | - Konstantinos T Konstantinidis
- Ocean Science & Engineering, School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA; School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Ramon Rossello-Mora
- Marine Microbiology Group, Department of Animal and Microbial Biodiversity, Mediterranean Institute for Advanced Studies (IMEDEA, CSIC-UIB), Esporles, Spain.
| |
Collapse
|
5
|
Chazan A, Das I, Fujiwara T, Murakoshi S, Rozenberg A, Molina-Márquez A, Sano FK, Tanaka T, Gómez-Villegas P, Larom S, Pushkarev A, Malakar P, Hasegawa M, Tsukamoto Y, Ishizuka T, Konno M, Nagata T, Mizuno Y, Katayama K, Abe-Yoshizumi R, Ruhman S, Inoue K, Kandori H, León R, Shihoya W, Yoshizawa S, Sheves M, Nureki O, Béjà O. Phototrophy by antenna-containing rhodopsin pumps in aquatic environments. Nature 2023; 615:535-540. [PMID: 36859551 DOI: 10.1038/s41586-023-05774-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/31/2023] [Indexed: 03/03/2023]
Abstract
Energy transfer from light-harvesting ketocarotenoids to the light-driven proton pump xanthorhodopsins has been previously demonstrated in two unique cases: an extreme halophilic bacterium1 and a terrestrial cyanobacterium2. Attempts to find carotenoids that bind and transfer energy to abundant rhodopsin proton pumps3 from marine photoheterotrophs have thus far failed4-6. Here we detected light energy transfer from the widespread hydroxylated carotenoids zeaxanthin and lutein to the retinal moiety of xanthorhodopsins and proteorhodopsins using functional metagenomics combined with chromophore extraction from the environment. The light-harvesting carotenoids transfer up to 42% of the harvested energy in the violet- or blue-light range to the green-light absorbing retinal chromophore. Our data suggest that these antennas may have a substantial effect on rhodopsin phototrophy in the world's lakes, seas and oceans. However, the functional implications of our findings are yet to be discovered.
Collapse
Affiliation(s)
- Ariel Chazan
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ishita Das
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel
| | - Takayoshi Fujiwara
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Shunya Murakoshi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Andrey Rozenberg
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ana Molina-Márquez
- Laboratory of Biochemistry and Molecular Biology, Faculty of Experimental Sciences, Marine International Campus of Excellence (CEIMAR), University of Huelva, Huelva, Spain
| | - Fumiya K Sano
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Tatsuki Tanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Patricia Gómez-Villegas
- Laboratory of Biochemistry and Molecular Biology, Faculty of Experimental Sciences, Marine International Campus of Excellence (CEIMAR), University of Huelva, Huelva, Spain
| | - Shirley Larom
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Alina Pushkarev
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Partha Malakar
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Masumi Hasegawa
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa, Japan
| | - Yuya Tsukamoto
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Tomohiro Ishizuka
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Masae Konno
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Takashi Nagata
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Yosuke Mizuno
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Kota Katayama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
| | - Rei Abe-Yoshizumi
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Sanford Ruhman
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
| | - Rosa León
- Laboratory of Biochemistry and Molecular Biology, Faculty of Experimental Sciences, Marine International Campus of Excellence (CEIMAR), University of Huelva, Huelva, Spain
| | - Wataru Shihoya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
| | - Susumu Yoshizawa
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan.
| | - Mordechai Sheves
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
| | - Oded Béjà
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
| |
Collapse
|
6
|
He S, Linz AM, Stevens SLR, Tran PQ, Moya-Flores F, Oyserman BO, Dwulit-Smith JR, Forest KT, McMahon KD. Diversity, distribution, and expression of opsin genes in freshwater lakes. Mol Ecol 2023; 32:2798-2817. [PMID: 36799010 DOI: 10.1111/mec.16891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 01/28/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Microbial rhodopsins are widely distributed in aquatic environments and may significantly contribute to phototrophy and energy budgets in global oceans. However, the study of freshwater rhodopsins has been largely limited. Here, we explored the diversity, ecological distribution, and expression of opsin genes that encode the apoproteins of type I rhodopsins in humic and clearwater lakes with contrasting physicochemical and optical characteristics. Using metagenomes and metagenome-assembled genomes, we recovered opsin genes from a wide range of taxa, mostly predicted to encode green light-absorbing proton pumps. Viral opsin and novel bacterial opsin clades were recovered. Opsin genes occurred more frequently in taxa from clearwater than from humic water, and opsins in some taxa have nontypical ion-pumping motifs that might be associated with physicochemical conditions of these two freshwater types. Analyses of the surface layer of 33 freshwater systems revealed an inverse correlation between opsin gene abundance and lake dissolved organic carbon (DOC). In humic water with high terrestrial DOC and light-absorbing humic substances, opsin gene abundance was low and dramatically declined within the first few meters, whereas the abundance remained relatively high along the bulk water column in clearwater lakes with low DOC, suggesting opsin gene distribution is influenced by lake optical properties and DOC. Gene expression analysis confirmed the significance of rhodopsin-based phototrophy in clearwater lakes and revealed different diel expressional patterns among major phyla. Overall, our analyses revealed freshwater opsin diversity, distribution and expression patterns, and suggested the significance of rhodopsin-based phototrophy in freshwater energy budgets, especially in clearwater lakes.
Collapse
Affiliation(s)
- Shaomei He
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Geoscience, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alexandra M Linz
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sarah L R Stevens
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Patricia Q Tran
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Francisco Moya-Flores
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ben O Oyserman
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jeffrey R Dwulit-Smith
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Program in Biophysics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Katrina T Forest
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Program in Biophysics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Katherine D McMahon
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|
7
|
Wang M, Wang H, Wang P, Fu HH, Li CY, Qin QL, Liang Y, Wang M, Chen XL, Zhang YZ, Zhang W. TCA cycle enhancement and uptake of monomeric substrates support growth of marine Roseobacter at low temperature. Commun Biol 2022; 5:705. [PMID: 35835984 PMCID: PMC9283371 DOI: 10.1038/s42003-022-03631-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 06/24/2022] [Indexed: 11/29/2022] Open
Abstract
Members of the marine Roseobacter group are ubiquitous in global oceans, but their cold-adaptive strategies have barely been studied. Here, as represented by Loktanella salsilacus strains enriched in polar regions, we firstly characterized the metabolic features of a cold-adapted Roseobacter by multi-omics, enzyme activities, and carbon utilization procedures. Unlike in most cold-adapted microorganisms, the TCA cycle is enhanced by accumulating more enzyme molecules, whereas genes for thiosulfate oxidation, sulfate reduction, nitrate reduction, and urea metabolism are all expressed at lower abundance when L. salsilacus was growing at 5 °C in comparison with higher temperatures. Moreover, a carbon-source competition experiment has evidenced the preferential use of glucose rather than sucrose at low temperature. This selective utilization is likely to be controlled by the carbon source uptake and transformation steps, which also reflects an economic calculation balancing energy production and functional plasticity. These findings provide a mechanistic understanding of how a Roseobacter member and possibly others as well counteract polar constraints. The metabolic adaptation of Loktanella salsilacus strains to cold involves an increase of enzymes involved in the TCA cycle and preferential use of glucose rather than sucrose at low temperature, providing insights into how Roseobacter adapts in polar regions.
Collapse
Affiliation(s)
- Meng Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.,Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China.,State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Huan Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Peng Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Hui-Hui Fu
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Chun-Yang Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Qi-Long Qin
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.,State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Yantao Liang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Min Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266373, China
| | - Yu-Zhong Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China. .,Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China. .,State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China. .,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266373, China.
| | - Weipeng Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
| |
Collapse
|
8
|
Tempel S, Bedo J, Talla E. From a large-scale genomic analysis of insertion sequences to insights into their regulatory roles in prokaryotes. BMC Genomics 2022; 23:451. [PMID: 35725380 PMCID: PMC9208149 DOI: 10.1186/s12864-022-08678-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/07/2022] [Indexed: 12/03/2022] Open
Abstract
Background Insertion sequences (ISs) are mobile repeat sequences and most of them can copy themselves to new host genome locations, leading to genome plasticity and gene regulation in prokaryotes. In this study, we present functional and evolutionary relationships between IS and neighboring genes in a large-scale comparative genomic analysis. Results IS families were located in all prokaryotic phyla, with preferential occurrence of IS3, IS4, IS481, and IS5 families in Alpha-, Beta-, and Gammaproteobacteria, Actinobacteria and Firmicutes as well as in eukaryote host-associated organisms and autotrophic opportunistic pathogens. We defined the concept of the IS-Gene couple (IG), which allowed to highlight the functional and regulatory impacts of an IS on the closest gene. Genes involved in transcriptional regulation and transport activities were found overrepresented in IG. In particular, major facilitator superfamily (MFS) transporters, ATP-binding proteins and transposases raised as favorite neighboring gene functions of IS hotspots. Then, evolutionary conserved IS-Gene sets across taxonomic lineages enabled the classification of IS-gene couples into phylum, class-to-genus, and species syntenic IS-Gene couples. The IS5, IS21, IS4, IS607, IS91, ISL3 and IS200 families displayed two to four times more ISs in the phylum and/or class-to-genus syntenic IGs compared to other IS families. This indicates that those families were probably inserted earlier than others and then subjected to horizontal transfer, transposition and deletion events over time. In phylum syntenic IG category, Betaproteobacteria, Crenarchaeota, Calditrichae, Planctomycetes, Acidithiobacillia and Cyanobacteria phyla act as IS reservoirs for other phyla, and neighboring gene functions are mostly related to transcriptional regulators. Comparison of IS occurrences with predicted regulatory motifs led to ~ 26.5% of motif-containing ISs with 2 motifs per IS in average. These results, concomitantly with short IS-Gene distances, suggest that those ISs would interfere with the expression of neighboring genes and thus form strong candidates for an adaptive pairing. Conclusions All together, our large-scale study provide new insights into the IS genetic context and strongly suggest their regulatory roles. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08678-3.
Collapse
Affiliation(s)
- Sebastien Tempel
- Aix Marseille University, CNRS, LCB, Laboratoire de Chimie Bactérienne, 13009, Marseille, France.
| | - Justin Bedo
- Bioinformatics Division, the Walter and Eliza Hall Institute, 1G Royal Parade, Parkville, VIC, 3052, Australia.,School of Computing and Information Systems, the University of Melbourne, Parkville, VIC, 3010, Australia
| | - Emmanuel Talla
- Aix Marseille University, CNRS, LCB, Laboratoire de Chimie Bactérienne, 13009, Marseille, France.
| |
Collapse
|
9
|
Xu S, Wang X, Zhang F, Jiang Y, Zhang Y, Cheng M, Yan X, Hong Q, He J, Qiu J. PicR as a MarR Family Transcriptional Repressor Multiply Controls the Transcription of Picolinic Acid Degradation Gene Cluster pic in Alcaligenes faecalis JQ135. Appl Environ Microbiol 2022; 88:e0017222. [PMID: 35604228 PMCID: PMC9195942 DOI: 10.1128/aem.00172-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/29/2022] [Indexed: 11/20/2022] Open
Abstract
Picolinic acid (PA) is a natural toxic pyridine derivative as well as an important intermediate used in the chemical industry. In a previous study, we identified a gene cluster, pic, that responsible for the catabolism of PA in Alcaligenes faecalis JQ135. However, the transcriptional regulation of the pic cluster remains known. This study showed that the entire pic cluster was composed of 17 genes and transcribed as four operons: picR, picCDEF, picB4B3B2B1, and picT1A1A2A3T2T3MN. Deletion of picR, encoding a putative MarR-type regulator, greatly shortened the lag phase of PA degradation. An electrophoretic mobility shift assay and DNase I footprinting showed that PicR has one binding site in the picR-picC intergenic region and two binding sites in the picB-picT1 intergenic region. The DNA sequences of the three binding sites have the palindromic characteristics of TCAG-N4-CTNN: the space consists of four nonspecific bases, and the four palindromic bases on the left and the first two palindromic bases on the right are strictly conserved, while the last two bases on the right vary among the three binding sites. An in vivo β-galactosidase activity reporter assay indicated that 6-hydroxypicolinic acid but not PA acted as a ligand of PicR, preventing PicR from binding to promoter regions and thus derepressing the transcription of the pic cluster. This study revealed the negative transcriptional regulation mechanism of PA degradation by PicR in A. faecalis JQ135 and provides new insights into the structure and function of the MarR-type regulator. IMPORTANCE The pic gene cluster was found to be responsible for PA degradation and widely distributed in Alpha-, Beta-, and Gammaproteobacteria. Thus, it is very necessary to understand the regulation mechanism of the pic cluster in these strains. This study revealed that PicR binds to three sites of the promoter regions of the pic cluster to multiply regulate the transcription of the pic cluster, which enables A. faecalis JQ135 to efficiently utilize PA. Furthermore, the study also found a unique palindrome sequence for binding of the MarR-type regulator. This study enhanced our understanding of microbial catabolism of environmental toxic pyridine derivatives.
Collapse
Affiliation(s)
- Siqiong Xu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xiao Wang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Fuyin Zhang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yinhu Jiang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yanting Zhang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Minggen Cheng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xin Yan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Qing Hong
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jian He
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jiguo Qiu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
10
|
Carotenoid binding in Gloeobacteria rhodopsin provides insights into divergent evolution of xanthorhodopsin types. Commun Biol 2022; 5:512. [PMID: 35637261 PMCID: PMC9151804 DOI: 10.1038/s42003-022-03429-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 04/29/2022] [Indexed: 11/08/2022] Open
Abstract
The position of carotenoid in xanthorhodopsin has been elucidated. However, a challenging expression of this opsin and a complex biosynthesis carotenoid in the laboratory hold back the insightful study of this rhodopsin. Here, we demonstrated co-expression of the xanthorhodopsin type isolated from Gloeobacter violaceus PCC 7421-Gloeobacter rhodopsin (GR) with a biosynthesized keto-carotenoid (canthaxanthin) targeting the carotenoid binding site. Direct mutation-induced changes in carotenoid-rhodopsin interaction revealed three crucial features: (1) carotenoid locked motif (CLM), (2) carotenoid aligned motif (CAM), and color tuning serines (CTS). Our single mutation results at 178 position (G178W) confirmed inhibition of carotenoid binding; however, the mutants showed better stability and proton pumping, which was also observed in the case of carotenoid binding characteristics. These effects demonstrated an adaptation of microbial rhodopsin that diverges from carotenoid harboring, along with expression in the dinoflagellate Pyrocystis lunula rhodopsin and the evolutionary substitution model. The study highlights a critical position of the carotenoid binding site, which significantly allows another protein engineering approach in the microbial rhodopsin family.
Collapse
|
11
|
A deep dive into the epibiotic communities on aquacultured sugar kelp Saccharina latissima in Southern New England. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
12
|
Wintertime Simulations Induce Changes in the Structure, Diversity and Function of Antarctic Sea Ice-Associated Microbial Communities. Microorganisms 2022; 10:microorganisms10030623. [PMID: 35336197 PMCID: PMC8950563 DOI: 10.3390/microorganisms10030623] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/04/2022] [Accepted: 03/11/2022] [Indexed: 11/26/2022] Open
Abstract
Antarctic sea-ice is exposed to a wide range of environmental conditions during its annual existence; however, there is very little information describing the change in sea-ice-associated microbial communities (SIMCOs) during the changing seasons. It is well known that during the solar seasons, SIMCOs play an important role in the polar carbon-cycle, by increasing the total photosynthetic primary production of the South Ocean and participating in the remineralization of phosphates and nitrogen. What remains poorly understood is the dynamic of SIMCO populations and their ecological contribution to carbon and nutrient cycling throughout the entire annual life of Antarctic sea-ice, especially in winter. Sea ice at this time of the year is an extreme environment, characterized by complete darkness (which stops photosynthesis), extremely low temperatures in its upper horizons (down to −45 °C) and high salinity (up to 150–250 psu) in its brine inclusions, where SIMCOs thrive. Without a permanent station, wintering expeditions in Antarctica are technically difficult; therefore, in this study, the process of autumn freezing was modelled under laboratory conditions, and the resulting ‘young ice’ was further incubated in cold and darkness for one month. The ice formation experiment was primarily designed to reproduce two critical conditions: (i) total darkness, causing the photosynthesis to cease, and (ii) the presence of a large amount of algae-derived organic matter. As expected, in the absence of photosynthesis, the activity of aerobic heterotrophs quickly created micro-oxic conditions, which caused the emergence of new players, namely facultative anaerobic and anaerobic microorganisms. Following this finding, we can state that Antarctic pack-ice and its surrounding ambient (under-ice seawater and platelet ice) are likely to be very dynamic and can quickly respond to environmental changes caused by the seasonal fluctuations. Given the size of Antarctic pack-ice, even in complete darkness and cessation of photosynthesis, its ecosystem appears to remain active, continuing to participate in global carbon-and-sulfur cycling under harsh conditions.
Collapse
|
13
|
Campbell K, Matero I, Bellas C, Turpin-Jelfs T, Anhaus P, Graeve M, Fripiat F, Tranter M, Landy JC, Sanchez-Baracaldo P, Leu E, Katlein C, Mundy CJ, Rysgaard S, Tedesco L, Haas C, Nicolaus M. Monitoring a changing Arctic: Recent advancements in the study of sea ice microbial communities. AMBIO 2022; 51:318-332. [PMID: 34822116 PMCID: PMC8692635 DOI: 10.1007/s13280-021-01658-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/05/2021] [Accepted: 10/20/2021] [Indexed: 05/25/2023]
Abstract
Sea ice continues to decline across many regions of the Arctic, with remaining ice becoming increasingly younger and more dynamic. These changes alter the habitats of microbial life that live within the sea ice, which support healthy functioning of the marine ecosystem and provision of resources for human-consumption, in addition to influencing biogeochemical cycles (e.g. air-sea CO2 exchange). With the susceptibility of sea ice ecosystems to climate change, there is a pressing need to fill knowledge gaps surrounding sea ice habitats and their microbial communities. Of fundamental importance to this goal is the development of new methodologies that permit effective study of them. Based on outcomes from the DiatomARCTIC project, this paper integrates existing knowledge with case studies to provide insight on how to best document sea ice microbial communities, which contributes to the sustainable use and protection of Arctic marine and coastal ecosystems in a time of environmental change.
Collapse
Affiliation(s)
- Karley Campbell
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Ilkka Matero
- Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Christopher Bellas
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Thomas Turpin-Jelfs
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Philipp Anhaus
- Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Martin Graeve
- Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Francois Fripiat
- Department Geosciences, Environment and Society, Université Libre de Bruxelles, Brussels, Belgium
| | - Martyn Tranter
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, UK
- Arctic Research Centre, Department of Bioscience, University of Aarhus, Aarhus, Denmark
| | - Jack Christopher Landy
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, UK
- Department of Physics and Technology, UiT The Arctic University of Norway, Tromsø, Norway
| | | | - Eva Leu
- Akvaplan-Niva AS, CIENS, Gaustadalleen 21, 0349 Oslo, Norway
| | - Christian Katlein
- Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - C. J Mundy
- Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB Canada
| | - Søren Rysgaard
- Arctic Research Centre, Department of Bioscience, University of Aarhus, Aarhus, Denmark
- Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB Canada
- Greenland Climate Research Centre, Nuuk, Greenland
| | | | - Christian Haas
- Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Marcel Nicolaus
- Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| |
Collapse
|
14
|
Assessment of Hydrocarbon Degradation Potential in Microbial Communities in Arctic Sea Ice. Microorganisms 2022; 10:microorganisms10020328. [PMID: 35208784 PMCID: PMC8879337 DOI: 10.3390/microorganisms10020328] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
The anthropogenic release of oil hydrocarbons into the cold marine environment is an increasing concern due to the elevated usage of sea routes and the exploration of new oil drilling sites in Arctic areas. The aim of this study was to evaluate prokaryotic community structures and the genetic potential of hydrocarbon degradation in the metagenomes of seawater, sea ice, and crude oil encapsulating the sea ice of the Norwegian fjord, Ofotfjorden. Although the results indicated substantial differences between the structure of prokaryotic communities in seawater and sea ice, the crude oil encapsulating sea ice (SIO) showed increased abundances of many genera-containing hydrocarbon-degrading organisms, including Bermanella, Colwellia, and Glaciecola. Although the metagenome of seawater was rich in a variety of hydrocarbon degradation-related functional genes (HDGs) associated with the metabolism of n-alkanes, and mono- and polyaromatic hydrocarbons, most of the normalized gene counts were highest in the clean sea ice metagenome, whereas in SIO, these counts were the lowest. The long-chain alkane degradation gene almA was detected from all the studied metagenomes and its counts exceeded ladA and alkB counts in both sea ice metagenomes. In addition, almA was related to the most diverse group of prokaryotic genera. Almost all 18 good- and high-quality metagenome-assembled genomes (MAGs) had diverse HDGs profiles. The MAGs recovered from the SIO metagenome belonged to the abundant taxa, such as Glaciecola, Bermanella, and Rhodobacteracea, in this environment. The genera associated with HDGs were often previously known as hydrocarbon-degrading genera. However, a substantial number of new associations, either between already known hydrocarbon-degrading genera and new HDGs or between genera not known to contain hydrocarbon degraders and multiple HDGs, were found. The superimposition of the results of comparing HDG associations with taxonomy, the HDG profiles of MAGs, and the full genomes of organisms in the KEGG database suggest that the found relationships need further investigation and verification.
Collapse
|
15
|
Touchette D, Altshuler I, Gostinčar C, Zalar P, Raymond-Bouchard I, Zajc J, McKay CP, Gunde-Cimerman N, Whyte LG. Novel Antarctic yeast adapts to cold by switching energy metabolism and increasing small RNA synthesis. THE ISME JOURNAL 2022; 16:221-232. [PMID: 34294882 PMCID: PMC8692454 DOI: 10.1038/s41396-021-01030-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 02/07/2023]
Abstract
The novel extremophilic yeast Rhodotorula frigidialcoholis, formerly R. JG1b, was isolated from ice-cemented permafrost in University Valley (Antarctic), one of coldest and driest environments on Earth. Phenotypic and phylogenetic analyses classified R. frigidialcoholis as a novel species. To characterize its cold-adaptive strategies, we performed mRNA and sRNA transcriptomic analyses, phenotypic profiling, and assessed ethanol production at 0 and 23 °C. Downregulation of the ETC and citrate cycle genes, overexpression of fermentation and pentose phosphate pathways genes, growth without reduction of tetrazolium dye, and our discovery of ethanol production at 0 °C indicate that R. frigidialcoholis induces a metabolic switch from respiration to ethanol fermentation as adaptation in Antarctic permafrost. This is the first report of microbial ethanol fermentation utilized as the major energy pathway in response to cold and the coldest temperature reported for natural ethanol production. R. frigidialcoholis increased its diversity and abundance of sRNAs when grown at 0 versus 23 °C. This was consistent with increase in transcription of Dicer, a key protein for sRNA processing. Our results strongly imply that post-transcriptional regulation of gene expression and mRNA silencing may be a novel evolutionary fungal adaptation in the cryosphere.
Collapse
Affiliation(s)
- D Touchette
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - I Altshuler
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - C Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- Lars Bolund Institute of Regenerative Medicine, BGI-Qingdao, Qingdao, China
| | - P Zalar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - I Raymond-Bouchard
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - J Zajc
- Agricultural Institute of Slovenia, Ljubljana, Slovenia
| | - C P McKay
- NASA Ames Research Center, Moffett Field, CA, USA
| | - N Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - L G Whyte
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC, Canada.
| |
Collapse
|
16
|
Maggiori C, Raymond-Bouchard I, Brennan L, Touchette D, Whyte L. MinION sequencing from sea ice cryoconites leads to de novo genome reconstruction from metagenomes. Sci Rep 2021; 11:21041. [PMID: 34702846 PMCID: PMC8548342 DOI: 10.1038/s41598-021-00026-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/30/2021] [Indexed: 01/04/2023] Open
Abstract
Genome reconstruction from metagenomes enables detailed study of individual community members, their metabolisms, and their survival strategies. Obtaining high quality metagenome-assembled genomes (MAGs) is particularly valuable in extreme environments like sea ice cryoconites, where the native consortia are recalcitrant to culture and strong astrobiology analogues. We evaluated three separate approaches for MAG generation from Allen Bay, Nunavut sea ice cryoconites-HiSeq-only, MinION-only, and hybrid (HiSeq + MinION)-where field MinION sequencing yielded a reliable metagenome. The hybrid assembly produced longer contigs, more coding sequences, and more total MAGs, revealing a microbial community dominated by Bacteroidetes. The hybrid MAGs also had the highest completeness, lowest contamination, and highest N50. A putatively novel species of Octadecabacter is among the hybrid MAGs produced, containing the genus's only known instances of genomic potential for nitrate reduction, denitrification, sulfate reduction, and fermentation. This study shows that the inclusion of MinION reads in traditional short read datasets leads to higher quality metagenomes and MAGs for more accurate descriptions of novel microorganisms in this extreme, transient habitat and has produced the first hybrid MAGs from an extreme environment.
Collapse
Affiliation(s)
- Catherine Maggiori
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21 111 Lakeshore Road, Macdonald Stewart Building, Room MS3-053, Ste. Anne-de-Bellevue, Quebec, H9X 3V9, Canada.
| | - Isabelle Raymond-Bouchard
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21 111 Lakeshore Road, Macdonald Stewart Building, Room MS3-053, Ste. Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Laura Brennan
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21 111 Lakeshore Road, Macdonald Stewart Building, Room MS3-053, Ste. Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - David Touchette
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21 111 Lakeshore Road, Macdonald Stewart Building, Room MS3-053, Ste. Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Lyle Whyte
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, 21 111 Lakeshore Road, Macdonald Stewart Building, Room MS3-053, Ste. Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| |
Collapse
|
17
|
Abu Bakar N, Lau Yii Chung B, Smykla J, Karsani SA, Alias SA. Protein homeostasis, regulation of energy production and activation of DNA damage-repair pathways are involved in the heat stress response of Pseudogymnoascus spp. Environ Microbiol 2021; 24:1849-1864. [PMID: 34528369 DOI: 10.1111/1462-2920.15776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 09/06/2021] [Accepted: 09/11/2021] [Indexed: 11/30/2022]
Abstract
Proteome changes can be used as an instrument to measure the effects of climate change, predict the possible future state of an ecosystem and the direction in which is headed. In this study, proteomic and GO functional enrichment analysis of six Pseudogymnoascus spp. isolated from various global biogeographical regions were carried out to determine their response to heat stress. In total, 2,122 proteins were identified with high confidence. Comparative quantitative analysis showed that changes in proteome profiles varied greatly between isolates from different biogeographical regions. Although the identities of the proteins that changed varied between the different regions, the functions they governed were similar. Gene Ontology analysis showed enrichment of proteins involved in multiple protective mechanisms, including the modulation of protein homeostasis, regulation of energy production, and activation of DNA damage and repair pathways. Our proteomic analysis did not show any clear relationship between protein changes and the strains' biogeographical origins. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Nurlizah Abu Bakar
- Institute of Ocean and Earth Sciences, C308, Institute of Advanced Studies Building, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.,National Antarctic Research Centre, B303, Institute of Advanced Studies Building, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Benjamin Lau Yii Chung
- Advanced Biotechnology and Breeding Centre, Malaysian Palm Oil Board, No. 6, Persiaran Institusi, Bandar Baru Bangi, 43000, Kajang, Selangor, Malaysia
| | - Jerzy Smykla
- Department of Biodiversity, Institute of Nature Conservation Polish Academy of Sciences, Mickiewicza 33, 31-120 Krakow, Poland
| | - Saiful Anuar Karsani
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Siti Aisyah Alias
- Institute of Ocean and Earth Sciences, C308, Institute of Advanced Studies Building, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.,National Antarctic Research Centre, B303, Institute of Advanced Studies Building, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| |
Collapse
|
18
|
Identification of Biomolecules Involved in the Adaptation to the Environment of Cold-Loving Microorganisms and Metabolic Pathways for Their Production. Biomolecules 2021; 11:biom11081155. [PMID: 34439820 PMCID: PMC8393263 DOI: 10.3390/biom11081155] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/30/2021] [Accepted: 08/01/2021] [Indexed: 12/22/2022] Open
Abstract
Cold-loving microorganisms of all three domains of life have unique and special abilities that allow them to live in harsh environments. They have acquired structural and molecular mechanisms of adaptation to the cold that include the production of anti-freeze proteins, carbohydrate-based extracellular polymeric substances and lipids which serve as cryo- and osmoprotectants by maintaining the fluidity of their membranes. They also produce a wide diversity of pigmented molecules to obtain energy, carry out photosynthesis, increase their resistance to stress and provide them with ultraviolet light protection. Recently developed analytical techniques have been applied as high-throughoutput technologies for function discovery and for reconstructing functional networks in psychrophiles. Among them, omics deserve special mention, such as genomics, transcriptomics, proteomics, glycomics, lipidomics and metabolomics. These techniques have allowed the identification of microorganisms and the study of their biogeochemical activities. They have also made it possible to infer their metabolic capacities and identify the biomolecules that are parts of their structures or that they secrete into the environment, which can be useful in various fields of biotechnology. This Review summarizes current knowledge on psychrophiles as sources of biomolecules and the metabolic pathways for their production. New strategies and next-generation approaches are needed to increase the chances of discovering new biomolecules.
Collapse
|
19
|
Abstract
Microbial rhodopsins are diverse photoreceptive proteins containing a retinal chromophore and are found in all domains of cellular life and are even encoded in genomes of viruses. These rhodopsins make up two families: type 1 rhodopsins and the recently discovered heliorhodopsins. These families have seven transmembrane helices with similar structures but opposing membrane orientation. Microbial rhodopsins participate in a portfolio of light-driven energy and sensory transduction processes. In this review we present data collected over the last two decades about these rhodopsins and describe their diversity, functions, and biological and ecological roles. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Andrey Rozenberg
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel; ,
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan;
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya 466-8555, Japan;
| | - Oded Béjà
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel; ,
| |
Collapse
|
20
|
Qu T, Hou C, Zhao X, Zhong Y, Guan C, Lin Z, Tang X, Wang Y. Bacteria associated with Ulva prolifera: a vital role in green tide formation and migration. HARMFUL ALGAE 2021; 108:102104. [PMID: 34588120 DOI: 10.1016/j.hal.2021.102104] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Ulva prolifera green tide in the Yellow Sea of China is a typical cross-regional marine ecological disaster. We hypothesized that the complex interactions between U. prolifera and its associated bacterial communities possibly impact the formation and outbreak of green tide. To test this hypothesis, the U. prolifera-associated bacterial community changes in the entire migration area were investigated through field sampling and high-throughput sequencing. The results showed that (1) with the green tide migration, the richness and diversity increased for U. prolifera epiphytic bacterial communities, while they decreased for seawater bacterial communities in the phycosphere. (2) The richness, diversity, and community composition of U. prolifera-associated bacteria changed more dramatically in the 35.00°N sea area. (3) Potential interactions between bacteria and U. prolifera existed during the entire long-distance migration of green tide, and six bacterial functional groups (BFGs) were defined. Growth-regulating BFG I and antibacterial and stress-resistance BFG II were the dominant communities in the early stage of the green tide migration, which have the role of regulating algal growth and synergistic protection. Heterotrophic BFG III and algicidal BFG IV were the dominant communities in the late stage of the green tide migration, and they were able to compete with algae for nutrients and inhibit algal growth. Nutritive BFG V and algae-derived nutritional type BFG VI symbiotically lived with algal host. Our study highlights the spatial and temporal complexity of U. prolifera-associated bacterial communities and provides valuable insights into the potential contribution of U. prolifera-associated bacterial communities to green tide outbreaks.
Collapse
Affiliation(s)
- Tongfei Qu
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Chengzong Hou
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Xinyu Zhao
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
| | - Yi Zhong
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Chen Guan
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Zhihao Lin
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
| | - Ying Wang
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
| |
Collapse
|
21
|
Rapp JZ, Sullivan MB, Deming JW. Divergent Genomic Adaptations in the Microbiomes of Arctic Subzero Sea-Ice and Cryopeg Brines. Front Microbiol 2021; 12:701186. [PMID: 34367102 PMCID: PMC8339730 DOI: 10.3389/fmicb.2021.701186] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
Subzero hypersaline brines are liquid microbial habitats within otherwise frozen environments, where concentrated dissolved salts prevent freezing. Such extreme conditions presumably require unique microbial adaptations, and possibly altered ecologies, but specific strategies remain largely unknown. Here we examined prokaryotic taxonomic and functional diversity in two seawater-derived subzero hypersaline brines: first-year sea ice, subject to seasonally fluctuating conditions; and ancient cryopeg, under relatively stable conditions geophysically isolated in permafrost. Overall, both taxonomic composition and functional potential were starkly different. Taxonomically, sea-ice brine communities (∼105 cells mL–1) had greater richness, more diversity and were dominated by bacterial genera, including Polaribacter, Paraglaciecola, Colwellia, and Glaciecola, whereas the more densely inhabited cryopeg brines (∼108 cells mL–1) lacked these genera and instead were dominated by Marinobacter. Functionally, however, sea ice encoded fewer accessory traits and lower average genomic copy numbers for shared traits, though DNA replication and repair were elevated; in contrast, microbes in cryopeg brines had greater genetic versatility with elevated abundances of accessory traits involved in sensing, responding to environmental cues, transport, mobile elements (transposases and plasmids), toxin-antitoxin systems, and type VI secretion systems. Together these genomic features suggest adaptations and capabilities of sea-ice communities manifesting at the community level through seasonal ecological succession, whereas the denser cryopeg communities appear adapted to intense bacterial competition, leaving fewer genera to dominate with brine-specific adaptations and social interactions that sacrifice some members for the benefit of others. Such cryopeg genomic traits provide insight into how long-term environmental stability may enable life to survive extreme conditions.
Collapse
Affiliation(s)
- Josephine Z Rapp
- School of Oceanography, University of Washington, Seattle, WA, United States
| | - Matthew B Sullivan
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, United States.,Department of Microbiology, Ohio State University, Columbus, OH, United States.,Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, United States.,Center of Microbiome Science, Ohio State University, Columbus, OH, United States
| | - Jody W Deming
- School of Oceanography, University of Washington, Seattle, WA, United States
| |
Collapse
|
22
|
The Gut Microbiota of Naturally Occurring and Laboratory Aquaculture Lytechinus variegatus Revealed Differences in the Community Composition, Taxonomic Co-Occurrence, and Predicted Functional Attributes. Appl Microbiol 2021. [DOI: 10.3390/applmicrobiol1020016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sea urchins, in many instances, are collected from the wild, maintained in the laboratory aquaculture environment, and used as model animals for various scientific investigations. It has been increasingly evident that diet-driven dysbiosis of the gut microbiome could affect animal health and physiology, thereby impacting the outcome of the scientific studies. In this study, we compared the gut microbiome between naturally occurring (ENV) and formulated diet-fed laboratory aquaculture (LAB) sea urchin Lytechinus variegatus by amplicon sequencing of the V4 region of the 16S rRNA gene and bioinformatics tools. Overall, the ENV gut digesta had higher taxa richness with an abundance of Propionigenium, Photobacterium, Roseimarinus, and Flavobacteriales. In contrast, the LAB group revealed fewer taxa richness, but noticeable abundances of Arcobacter, Agarivorans, and Shewanella. However, Campylobacteraceae, primarily represented by Arcobacter spp., was commonly associated with the gut tissues of both ENV and LAB groups whereas the gut digesta had taxa from Gammaproteobacteria, particularly Vibrio spp. Similarly, the co-occurrence network displayed taxonomic organizations interconnected by Arcobacter and Vibrio as being the key taxa in gut tissues and gut digesta, respectively. Predicted functional analysis of the gut tissues microbiota of both ENV and LAB groups showed a higher trend in energy-related metabolisms, whereas amino acids, carbohydrate, and lipid metabolisms heightened in the gut digesta. This study provides an outlook of the laboratory-formulated diet-fed aquaculture L. variegatus gut microbiome and predicted metabolic profile as compared to the naturally occurring animals, which should be taken into consideration for consistency, reproducibility, and translatability of scientific studies.
Collapse
|
23
|
|
24
|
Silva TRE, Silva LCF, de Queiroz AC, Alexandre Moreira MS, de Carvalho Fraga CA, de Menezes GCA, Rosa LH, Bicas J, de Oliveira VM, Duarte AWF. Pigments from Antarctic bacteria and their biotechnological applications. Crit Rev Biotechnol 2021; 41:809-826. [PMID: 33622142 DOI: 10.1080/07388551.2021.1888068] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pigments from microorganisms have triggered great interest in the market, mostly by their "natural" appeal, their favorable production conditions, in addition to the potential new chemical structures or naturally overproducing strains. They have been used in: food, feed, dairy, textile, pharmaceutical, and cosmetic industries. The high rate of pigment production in microorganisms recovered from Antarctica in response to selective pressures such as: high UV radiation, low temperatures, and freezing and thawing cycles makes this a unique biome which means that much of its biological heritage cannot be found elsewhere on the planet. This vast arsenal of pigmented molecules has different functions in bacteria and may exhibit different biotechnological activities, such as: extracellular sunscreens, photoprotective function, antimicrobial activity, biodegradability, etc. However, many challenges for the commercial use of these compounds have yet to be overcome, such as: the low stability of natural pigments in cosmetic formulations, the change in color when subjected to pH variations, the low yield and the high costs in their production. This review surveys the different types of natural pigments found in Antarctic bacteria, classifying them according to their chemical structure. Finally, we give an overview of the main pigments that are used commercially today.
Collapse
Affiliation(s)
- Tiago Rodrigues E Silva
- Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrárias, Universidade Estadual de Campinas, UNICAMP, Campinas, Brazil
| | | | | | | | | | | | - Luiz Henrique Rosa
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juliano Bicas
- Departamento de Ciência de Alimentos, Universidade Estadual de Campinas, UNICAMP, Campinas, Brazil
| | - Valéria Maia de Oliveira
- Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrárias, Universidade Estadual de Campinas, UNICAMP, Campinas, Brazil
| | | |
Collapse
|
25
|
Kurth D, Elias D, Rasuk MC, Contreras M, Farías ME. Carbon fixation and rhodopsin systems in microbial mats from hypersaline lakes Brava and Tebenquiche, Salar de Atacama, Chile. PLoS One 2021; 16:e0246656. [PMID: 33561170 PMCID: PMC7872239 DOI: 10.1371/journal.pone.0246656] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 01/25/2021] [Indexed: 01/08/2023] Open
Abstract
In this work, molecular diversity of two hypersaline microbial mats was compared by Whole Genome Shotgun (WGS) sequencing of environmental DNA from the mats. Brava and Tebenquiche are lakes in the Salar de Atacama, Chile, where microbial communities are growing in extreme conditions, including high salinity, high solar irradiance, and high levels of toxic metals and metaloids. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. The mat from Brava was more rich and diverse, with a higher number of different taxa and with species more evenly distributed. At the phylum level, Proteobacteria, Cyanobacteria, Chloroflexi, Bacteroidetes and Firmicutes were the most abundant, including ~75% of total sequences. At the genus level, the most abundant sequences were affilitated to anoxygenic phototropic and cyanobacterial genera. In Tebenquiche mats, Proteobacteria and Bacteroidetes covered ~70% of the sequences, and 13% of the sequences were affiliated to Salinibacter genus, thus addressing the lower diversity. Regardless of the differences at the taxonomic level, functionally the two mats were similar. Thus, similar roles could be fulfilled by different organisms. Carbon fixation through the Wood-Ljungdahl pathway was well represented in these datasets, and also in other mats from Andean lakes. In spite of presenting less taxonomic diversity, Tebenquiche mats showed increased abundance and variety of rhodopsin genes. Comparison with other metagenomes allowed identifying xantorhodopsins as hallmark genes not only from Brava and Tebenquiche mats, but also for other mats developing at high altitudes in similar environmental conditions.
Collapse
Affiliation(s)
- Daniel Kurth
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina
| | - Dario Elias
- Facultad de Ingeniería, Universidad Nacional de Entre Ríos, Oro Verde, Entre Ríos, Argentina
| | - María Cecilia Rasuk
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina
| | | | - María Eugenia Farías
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina
| |
Collapse
|
26
|
Walker AM, Leigh MB, Mincks SL. Patterns in Benthic Microbial Community Structure Across Environmental Gradients in the Beaufort Sea Shelf and Slope. Front Microbiol 2021; 12:581124. [PMID: 33584606 PMCID: PMC7876419 DOI: 10.3389/fmicb.2021.581124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 01/05/2021] [Indexed: 11/13/2022] Open
Abstract
The paradigm of tight pelagic-benthic coupling in the Arctic suggests that current and future fluctuations in sea ice, primary production, and riverine input resulting from global climate change will have major impacts on benthic ecosystems. To understand how these changes will affect benthic ecosystem function, we must characterize diversity, spatial distribution, and community composition for all faunal components. Bacteria and archaea link the biotic and abiotic realms, playing important roles in organic matter (OM) decomposition, biogeochemical cycling, and contaminant degradation, yet sediment microbial communities have rarely been examined in the North American Arctic. Shifts in microbial community structure and composition occur with shifts in OM inputs and contaminant exposure, with implications for shifts in ecological function. Furthermore, the characterization of benthic microbial communities provides a foundation from which to build focused experimental research. We assessed diversity and community structure of benthic prokaryotes in the upper 1 cm of sediments in the southern Beaufort Sea (United States and Canada), and investigated environmental correlates of prokaryotic community structure over a broad spatial scale (spanning 1,229 km) at depths ranging from 17 to 1,200 m. Based on hierarchical clustering, we identified four prokaryotic assemblages from the 85 samples analyzed. Two were largely delineated by the markedly different environmental conditions in shallow shelf vs. upper continental slope sediments. A third assemblage was mainly comprised of operational taxonomic units (OTUs) shared between the shallow shelf and upper slope assemblages. The fourth assemblage corresponded to sediments receiving heavier OM loading, likely resulting in a shallower anoxic layer. These sites may also harbor microbial mats and/or methane seeps. Substructure within these assemblages generally reflected turnover along a longitudinal gradient, which may be related to the quantity and composition of OM deposited to the seafloor; bathymetry and the Mackenzie River were the two major factors influencing prokaryote distribution on this scale. In a broader geographical context, differences in prokaryotic community structure between the Beaufort Sea and Norwegian Arctic suggest that benthic microbes may reflect regional differences in the hydrography, biogeochemistry, and bathymetry of Arctic shelf systems.
Collapse
Affiliation(s)
- Alexis M Walker
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Mary Beth Leigh
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Sarah L Mincks
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, United States
| |
Collapse
|
27
|
Tendulkar S, Hattiholi A, Chavadar M, Dodamani S. Psychrophiles: A journey of hope. J Biosci 2021; 46:64. [PMID: 34219740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Psychrophiles are organisms living in extremely cold conditions within the temperature range of -20°C to +10°C. These organisms survive in harsh environment by modulating their genetic make-up to thrive in extremely cold conditions. These cold-adaptations are closely associated with changes in the life forms, gene expression, and proteins, enzymes, lipids, etc. This review gives a brief description of the life and genetic adaptations of psychrophiles for their survival in extreme conditions as well as the bioactive compounds that are potential antimicrobials.
Collapse
Affiliation(s)
- Shivani Tendulkar
- Dr. Prabhakar Kore Basic Science Research Center, KLE Academy of Higher Education and Research, Belagavi 590 010, India
| | | | | | | |
Collapse
|
28
|
Kopejtka K, Tomasch J, Zeng Y, Selyanin V, Dachev M, Piwosz K, Tichý M, Bína D, Gardian Z, Bunk B, Brinkmann H, Geffers R, Sommaruga R, Koblížek M. Simultaneous Presence of Bacteriochlorophyll and Xanthorhodopsin Genes in a Freshwater Bacterium. mSystems 2020; 5:e01044-20. [PMID: 33361324 PMCID: PMC7762795 DOI: 10.1128/msystems.01044-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/30/2020] [Indexed: 01/01/2023] Open
Abstract
Photoheterotrophic bacteria represent an important part of aquatic microbial communities. There exist two fundamentally different light-harvesting systems: bacteriochlorophyll-containing reaction centers or rhodopsins. Here, we report a photoheterotrophic Sphingomonas strain isolated from an oligotrophic lake, which contains complete sets of genes for both rhodopsin-based and bacteriochlorophyll-based phototrophy. Interestingly, the identified genes were not expressed when cultured in liquid organic media. Using reverse transcription quantitative PCR (RT-qPCR), RNA sequencing, and bacteriochlorophyll a quantification, we document that bacteriochlorophyll synthesis was repressed by high concentrations of glucose or galactose in the medium. Coactivation of photosynthesis genes together with genes for TonB-dependent transporters suggests the utilization of light energy for nutrient import. The photosynthetic units were formed by ring-shaped light-harvesting complex 1 and reaction centers with bacteriochlorophyll a and spirilloxanthin as the main light-harvesting pigments. The identified rhodopsin gene belonged to the xanthorhodopsin family, but it lacks salinixanthin antenna. In contrast to bacteriochlorophyll, the expression of xanthorhodopsin remained minimal under all experimental conditions tested. Since the gene was found in the same operon as a histidine kinase, we propose that it might serve as a light sensor. Our results document that photoheterotrophic Sphingomonas bacteria use the energy of light under carbon-limited conditions, while under carbon-replete conditions, they cover all their metabolic needs through oxidative phosphorylation.IMPORTANCE Phototrophic organisms are key components of many natural environments. There exist two main phototrophic groups: species that collect light energy using various kinds of (bacterio)chlorophylls and species that utilize rhodopsins. Here, we present a freshwater bacterium Sphingomonas sp. strain AAP5 which contains genes for both light-harvesting systems. We show that bacteriochlorophyll-based reaction centers are repressed by light and/or glucose. On the other hand, the rhodopsin gene was not expressed significantly under any of the experimental conditions. This may indicate that rhodopsin in Sphingomonas may have other functions not linked to bioenergetics.
Collapse
Affiliation(s)
- Karel Kopejtka
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Jürgen Tomasch
- Research Group Microbial Communication, Technical University of Braunschweig, Braunschweig, Germany
| | - Yonghui Zeng
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
- Department of Environmental Science, Aarhus University, Aarhus, Denmark
| | - Vadim Selyanin
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Marko Dachev
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Kasia Piwosz
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Martin Tichý
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - David Bína
- Institute of Plant Molecular Biology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Institute of Parasitology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Zdenko Gardian
- Institute of Plant Molecular Biology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Institute of Parasitology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Henner Brinkmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Robert Geffers
- Research Group Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ruben Sommaruga
- Laboratory of Aquatic Photobiology and Plankton Ecology, Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Michal Koblížek
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| |
Collapse
|
29
|
Physiological and Molecular Responses to Main Environmental Stressors of Microalgae and Bacteria in Polar Marine Environments. Microorganisms 2020; 8:microorganisms8121957. [PMID: 33317109 PMCID: PMC7764121 DOI: 10.3390/microorganisms8121957] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 12/18/2022] Open
Abstract
The Arctic and Antarctic regions constitute 14% of the total biosphere. Although they differ in their physiographic characteristics, both are strongly affected by snow and ice cover changes, extreme photoperiods and low temperatures, and are still largely unexplored compared to more accessible sites. This review focuses on microalgae and bacteria from polar marine environments and, in particular, on their physiological and molecular responses to harsh environmental conditions. The data reported in this manuscript show that exposure to cold, increase in CO2 concentration and salinity, high/low light, and/or combination of stressors induce variations in species abundance and distribution for both polar bacteria and microalgae, as well as changes in growth rate and increase in cryoprotective compounds. The use of -omics techniques also allowed to identify specific gene losses and gains which could have contributed to polar environmental adaptation, and metabolic shifts, especially related to lipid metabolism and defence systems, such as the up-regulation of ice binding proteins, chaperones and antioxidant enzymes. However, this review also provides evidence that -omics resources for polar species are still few and several sequences still have unknown functions, highlighting the need to further explore polar environments, the biology and ecology of the inhabiting bacteria and microalgae, and their interactions.
Collapse
|
30
|
Chen M, Song Y, Feng X, Tang K, Jiao N, Tian J, Zhang Y. Genomic Characteristics and Potential Metabolic Adaptations of Hadal Trench Roseobacter and Alteromonas Bacteria Based on Single-Cell Genomics Analyses. Front Microbiol 2020; 11:1739. [PMID: 32793171 PMCID: PMC7393951 DOI: 10.3389/fmicb.2020.01739] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 07/03/2020] [Indexed: 11/30/2022] Open
Abstract
Heterotrophic bacteria such as those from the Roseobacter group and genus Alteromonas dominate the hadal zones of oceans; however, we know little about the genomic characteristics and potential metabolic adaptations of hadal trench-dwelling bacteria. Here, we report multiple single amplified genomes (SAGs) belonging to Roseobacter and Alteromonas, recovered from the hadal zone of the Mariana Trench. While phylogenetic analyses show that these hadal SAGs cluster with their surface relatives, an analysis of genomic recruitment indicates that they have higher relative abundances in the hadal zone of the Mariana Trench. Comparative genomic analyses between the hadal SAGs and reference genomes of closely related shallow-water relatives indicate that genes involved in the mobilome (prophages and transposons) are overrepresented among the unique genes of the hadal Roseobacter and Alteromonas SAGs; the functional proteins encoded by this category of genes also shows higher amino acid sequence variation than those encoded by other gene sets within the Roseobacter SAGs. We also found that genes involved in cell wall/membrane/envelope biogenesis, transcriptional regulation, and metal transport may be important for the adaptation of hadal Roseobacter and Alteromonas lineages. These results imply that the modification of cell surface-related proteins and transporters is the major direction of genomic evolution in Roseobacter and Alteromonas bacteria adapting to the hadal environment, and that prophages and transposons may be the key factors driving this process.
Collapse
Affiliation(s)
- Mingming Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen, China
| | - Yu Song
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen, China
| | - Xiaoyuan Feng
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kai Tang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen, China
| | - Jiwei Tian
- Physical Oceanography Laboratory, Ocean University of China, Qingdao, China
| | - Yao Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen, China
| |
Collapse
|
31
|
Tarlachkov SV, Shevchuk TV, Montero-Calasanz MDC, Starodumova IP. Diversity of rhodopsins in cultivated bacteria of the family Geodermatophilaceae associated with non-aquatic environments. Bioinformatics 2020; 36:1668-1672. [PMID: 31711117 DOI: 10.1093/bioinformatics/btz840] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/30/2019] [Accepted: 11/10/2019] [Indexed: 12/25/2022] Open
Abstract
MOTIVATION A small amount of research is focused on investigation of rhodopsins in cultivated bacteria isolated from non-aquatic environments. Furthermore, the abundance of these proteins in strains from hot and arid habitats was not reported previously. Since there is an insignificant amount of such isolates, the enigmatic role of the rhodopsins in dry ecological niches is still poorly understood. The members of the family Geodermatophilaceae could be used as interesting objects to search for new rhodopsin genes that will provide novel insights into versatility and importance of these proteins in non-aquatic conditions. RESULTS This is the first report of the abundance of different rhodopsins in cultivated bacteria isolated from hot and arid ecological niches. A total of 31 rhodopsin genes were identified in 51 analyzed genomes of strains belonging to the family Geodermatophilaceae. Overall, 88% of the strains harbouring rhodopsins are isolated from non-aquatic environments. It was found that 82% of strains belonging to the genus Geodermatophilus have at least one gene as compared to 38% of strains of other genera which contain rhodopsins. Analysis of key amino acids revealed two types of the studied proteins: DTE type (putative proton pump) and NDQ type (putative sodium pump). Proton pumps were divided into two subtypes (DTEW and DTEF) according to phylogenetic analysis and the presence of highly conserved tryptophan or phenylalanine at position 182. Among all studied rhodopsins DTEF subtype is the most unique one, identified only in this family. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Sergey V Tarlachkov
- All-Russian Collection of Microorganisms, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC Pushchino Scientific Center for Biological Research.,Department of Plant Molecular Biology and Biotechnology, Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino 142290, Russia
| | - Taras V Shevchuk
- Department of Plant Molecular Biology and Biotechnology, Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino 142290, Russia
| | - Maria Del Carmen Montero-Calasanz
- Plant and Microbial Biology Research Group, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Irina P Starodumova
- All-Russian Collection of Microorganisms, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC Pushchino Scientific Center for Biological Research
| |
Collapse
|
32
|
MhpA Is a Hydroxylase Catalyzing the Initial Reaction of 3-(3-Hydroxyphenyl)Propionate Catabolism in Escherichia coli K-12. Appl Environ Microbiol 2020; 86:AEM.02385-19. [PMID: 31811039 DOI: 10.1128/aem.02385-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/04/2019] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli K-12 and some other strains have been reported to be capable of utilizing 3-(3-hydroxyphenyl)propionate (3HPP), one of the phenylpropanoids from lignin. Although other enzymes involved in 3HPP catabolism and their corresponding genes from its degraders have been identified, 3HPP 2-hydroxylase, catalyzing the first step of its catabolism, has yet to be functionally identified at biochemical and genetic levels. In this study, we investigated the function and characteristics of MhpA from E. coli strain K-12 (MhpAK-12). Gene deletion and complementation showed that mhpA was vital for its growth on 3HPP, but the mhpA deletion strain was still able to grow on 3-(2,3-dihydroxyphenyl)propionate (DHPP), the hydroxylation product transformed from 3HPP by MhpAK-12 MhpAK-12 was overexpressed and purified, and it was likely a polymer and tightly bound with an approximately equal number of moles of FAD. Using NADH or NADPH as a cofactor, purified MhpAK-12 catalyzed the conversion of 3HPP to DHPP at a similar efficiency. The conversion from 3HPP to DHPP by purified MhpAK-12 was confirmed using high-performance liquid chromatography and liquid chromatography-mass spectrometry. Bioinformatics analysis indicated that MhpAK-12 and its putative homologues belonged to taxa that were phylogenetically distant from functionally identified FAD-containing monooxygenases (hydroxylases). Interestingly, MhpAK-12 has approximately an extra 150 residues at its C terminus in comparison to its close homologues, but its truncated versions MhpAK-12 400 and MhpAK-12 480 (with 154 and 74 residues deleted from the C terminus, respectively) both lost their activities. Thus, MhpAK-12 has been confirmed to be a 3HPP 2-hydroxylase catalyzing the conversion of 3HPP to DHPP, the initial reaction of 3HPP degradation.IMPORTANCE Phenylpropionate and its hydroxylated derivatives resulted from lignin degradation ubiquitously exist on the Earth. A number of bacterial strains have the ability to grow on 3HPP, one of the above derivatives. The hydroxylation was thought to be the initial and vital step for its aerobic catabolism via the meta pathway. The significance of our research is the functional identification and characterization of the purified 3HPP 2-hydroxylase MhpA from Escherichia coli K-12 at biochemical and genetic levels, since this enzyme has not previously been expressed from its encoding gene, purified, and characterized in any bacteria. It will not only fill a gap in our understanding of 3HPP 2-hydroxylase and its corresponding gene for the critical step in microbial 3HPP catabolism but also provide another example of the diversity of microbial degradation of plant-derived phenylpropionate and its hydroxylated derivatives.
Collapse
|
33
|
Savoca S, Lo Giudice A, Papale M, Mangano S, Caruso C, Spanò N, Michaud L, Rizzo C. Antarctic sponges from the Terra Nova Bay (Ross Sea) host a diversified bacterial community. Sci Rep 2019; 9:16135. [PMID: 31695084 PMCID: PMC6834628 DOI: 10.1038/s41598-019-52491-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/04/2019] [Indexed: 11/23/2022] Open
Abstract
Sponges represent important habitats for a community of associated (micro)organisms. Even if sponges dominate vast areas of the Antarctic shelves, few investigations have been performed on Antarctic sponge-associated bacteria. Using a culture-dependent approach, the composition of the bacterial communities associated with 14 Antarctic sponge species from different sites within the Terra Nova Bay (Ross Sea) area was analyzed. Overall, isolates were mainly affiliated to Gammaproteobacteria, followed by Actinobacteria and CF group of Bacteroidetes, being the genera Pseudoalteromonas, Arthrobacter and Gillisia predominant, respectively. Alphaproteobacteria and Firmicutes were less represented. Cluster analyses highlighted similarities/differences among the sponge-associated bacterial communities, also in relation to the sampling site. The gammaproteobacterial Pseudoalteromonas sp. SER45, Psychrobacter sp. SER48, and Shewanella sp. SER50, and the actinobacterial Arthrobacter sp. SER44 phylotypes occurred in association with almost all the analyzed sponge species. However, except for SER50, these phylotypes were retrieved also in seawater, indicating that they may be transient within the sponge body. The differences encountered within the bacterial communities may depend on the different sites of origin, highlighting the importance of the habitat in structuring the composition of the associated bacterial assemblages. Our data support the hypothesis of specific ecological interactions between bacteria and Porifera.
Collapse
Affiliation(s)
- Serena Savoca
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Universitàdi Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Angelina Lo Giudice
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Universitàdi Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy. .,Istituto di Scienze Polari, Consiglio Nazionale delle Ricerche (CNR-ISP), Spianata San Raineri 86, 98122, Messina, Italy.
| | - Maria Papale
- Istituto di Scienze Polari, Consiglio Nazionale delle Ricerche (CNR-ISP), Spianata San Raineri 86, 98122, Messina, Italy
| | - Santina Mangano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Universitàdi Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Consolazione Caruso
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Universitàdi Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Nunziacarla Spanò
- Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali, A.O.U. Policlinico "G. Martino", Torre Biologica, Via Consolare Valeria, 98125, Messina, Italy
| | | | - Carmen Rizzo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Universitàdi Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy
| |
Collapse
|
34
|
Cao S, Zhang F, He J, Ji Z, Zhou Q. Water masses influence bacterioplankton community structure in summer Kongsfjorden. Extremophiles 2019; 24:107-120. [PMID: 31679078 DOI: 10.1007/s00792-019-01139-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 10/08/2019] [Indexed: 10/25/2022]
Abstract
To ascertain the saying "Everything is everywhere, but the environment selects", it was imperative to find out the main factor influencing bacterioplankton composition at genus level of Kongsfjorden where was influenced both by glacier melting water and Atlantic water. Thus, bacterioplankton diversity was investigated using pyrosequencing. In addition, nutrients, chlorophyll a, in situ temperature and salinity were measured. There were seventeen of 33 identified genera with relative abundance > 0.1%. Redundancy analysis showed that 73.02% of bacterioplankton community variance could be explained by environmental parameters. Furthermore, most of the abundant genera demonstrated significant correlation with environment parameters revealed by correlation analysis. Moreover, phosphate, nitrate and Chl a concentration, and the abundance of top nine identified genera varied with water mass significantly as shown by analysis of variance. Our results supported the notion that environmental factors, especially water mass had significant effect on bacterioplankton distribution at genus level. Considering the high sensitivity to environmental change and low error rate in identification, bacterioplankton at genus level could be potential bio-markers for monitoring environmental changes.
Collapse
Affiliation(s)
- Shunan Cao
- Key Laboratory for Polar Science SOA, Polar Research Institute of China, No. 451 JinQiao Road, Pudong Avenue, Shanghai, 200136, China
| | - Fang Zhang
- Key Laboratory for Polar Science SOA, Polar Research Institute of China, No. 451 JinQiao Road, Pudong Avenue, Shanghai, 200136, China
| | - Jianfeng He
- Key Laboratory for Polar Science SOA, Polar Research Institute of China, No. 451 JinQiao Road, Pudong Avenue, Shanghai, 200136, China.
| | - Zhongqiang Ji
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China
| | - Qiming Zhou
- School of Life Science and Technology, Harbin Institute of Technology, 2 Yikuang Street, Harbin, 150080, China.,ChosenMed Technology (Beijing) Company Limited, Jinghai Industrial Park, Economic and Technological Development Area, Beijing, 100176, China
| |
Collapse
|
35
|
Abstract
Horizontal gene transfer (HGT) is the movement of genetic material between organisms other than by reproduction, which plays an important role in bacterial evolution. Often, mobile genetic elements such as plasmids are involved in HGT. In this study, we present phylogenetic, biogeographic, and functional analyses of a previously unrecognized plasmid that is found with 100% sequence identity in multiple distinct bacterial genera obtained from geographically separated locations. This is the only known instance where actual nucleotide identity and not only high synteny has been described for plasmids in environmental organisms. Furthermore, we provide experimental evidence for the potential of this plasmid to be transmitted across bacterial orders, thereby increasing our understanding of evolution and microbial niche adaptation in the environment. Horizontal gene transfer (HGT) plays an important role in bacterial evolution and serves as a driving force for bacterial diversity and versatility. HGT events often involve mobile genetic elements like plasmids, which can promote their own dissemination by associating with adaptive traits in the gene pool of the so-called mobilome. Novel traits that evolve through HGT can therefore lead to the exploitation of new ecological niches, prompting an adaptive radiation of bacterial species. In this study, we present phylogenetic, biogeographic, and functional analyses of a previously unrecognized RepL-type plasmid found in diverse members of the marine Roseobacter group across the globe. Noteworthy, 100% identical plasmids were detected in phylogenetically and geographically distant bacteria, revealing a so-far overlooked, but environmentally highly relevant vector for HGT. The genomic and functional characterization of this plasmid showed a completely conserved backbone dedicated to replication, stability, and mobilization as well as an interchangeable gene cassette with highly diverse, but recurring motifs. The majority of the latter appear to be involved in mechanisms coping with toxins and/or pollutants in the marine environment. Furthermore, we provide experimental evidence that the plasmid has the potential to be transmitted across bacterial orders, thereby increasing our understanding of evolution and microbial niche adaptation in the environment.
Collapse
|
36
|
Kopejtka K, Lin Y, Jakubovičová M, Koblížek M, Tomasch J. Clustered Core- and Pan-Genome Content on Rhodobacteraceae Chromosomes. Genome Biol Evol 2019; 11:2208-2217. [PMID: 31273387 PMCID: PMC6699656 DOI: 10.1093/gbe/evz138] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2019] [Indexed: 12/18/2022] Open
Abstract
In Bacteria, chromosome replication starts at a single origin of replication and proceeds on both replichores. Due to its asymmetric nature, replication influences chromosome structure and gene organization, mutation rate, and expression. To date, little is known about the distribution of highly conserved genes over the bacterial chromosome. Here, we used a set of 101 fully sequenced Rhodobacteraceae representatives to analyze the relationship between conservation of genes within this family and their distance from the origin of replication. Twenty-two of the analyzed species had core genes clustered significantly closer to the origin of replication with representatives of the genus Celeribacter being the most apparent example. Interestingly, there were also eight species with the opposite organization. In particular, Rhodobaca barguzinensis and Loktanella vestfoldensis showed a significant increase of core genes with distance from the origin of replication. The uneven distribution of low-conserved regions is in particular pronounced for genomes in which the halves of one replichore differ in their conserved gene content. Phage integration and horizontal gene transfer partially explain the scattered nature of Rhodobacteraceae genomes. Our findings lay the foundation for a better understanding of bacterial genome evolution and the role of replication therein.
Collapse
Affiliation(s)
- Karel Kopejtka
- Laboratory of Anoxygenic Phototrophs, Center Algatech, Institute of Microbiology CAS, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Yan Lin
- Department of Physics, School of Science, Tianjin University, China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Markéta Jakubovičová
- Faculty of Information Technology, Czech Technical University in Prague, Czech Republic
| | - Michal Koblížek
- Laboratory of Anoxygenic Phototrophs, Center Algatech, Institute of Microbiology CAS, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jürgen Tomasch
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| |
Collapse
|
37
|
Iizuka A, Kajimoto K, Fujisawa T, Tsukamoto T, Aizawa T, Kamo N, Jung KH, Unno M, Demura M, Kikukawa T. Functional importance of the oligomer formation of the cyanobacterial H + pump Gloeobacter rhodopsin. Sci Rep 2019; 9:10711. [PMID: 31341208 PMCID: PMC6656774 DOI: 10.1038/s41598-019-47178-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/11/2019] [Indexed: 02/07/2023] Open
Abstract
Many microbial rhodopsins self-oligomerize, but the functional consequences of oligomerization have not been well clarified. We examined the effects of oligomerization of a H+ pump, Gloeobacter rhodopsin (GR), by using nanodisc containing trimeric and monomeric GR. The monomerization did not appear to affect the unphotolyzed GR. However, we found a significant impact on the photoreaction: The monomeric GR showed faint M intermediate formation and negligible H+ transfer reactions. These changes reflected the elevated pKa of the Asp121 residue, whose deprotonation is a prerequisite for the functional photoreaction. Here, we focused on His87, which is a neighboring residue of Asp121 and conserved among eubacterial H+ pumps but replaced by Met in an archaeal H+ pump. We found that the H87M mutation removes the “monomerization effects”: Even in the monomeric state, H87M contained the deprotonated Asp121 and showed both M formation and distinct H+ transfer reactions. Thus, for wild-type GR, monomerization probably strengthens the Asp121-His87 interaction and thereby elevates the pKa of Asp121 residue. This strong interaction might occur due to the loosened protein structure and/or the disruption of the interprotomer interaction of His87. Thus, the trimeric assembly of GR enables light-induced H+ transfer reactions through adjusting the positions of key residues.
Collapse
Affiliation(s)
- Azusa Iizuka
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Kousuke Kajimoto
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga, 840-8502, Japan
| | - Tomotsumi Fujisawa
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga, 840-8502, Japan
| | - Takashi Tsukamoto
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0021, Japan
| | - Tomoyasu Aizawa
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0021, Japan
| | - Naoki Kamo
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Kwang-Hwan Jung
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, 04107, Republic of Korea
| | - Masashi Unno
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga, 840-8502, Japan
| | - Makoto Demura
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0021, Japan
| | - Takashi Kikukawa
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan. .,Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0021, Japan.
| |
Collapse
|
38
|
Identification and Characterization of a Novel pic Gene Cluster Responsible for Picolinic Acid Degradation in Alcaligenes faecalis JQ135. J Bacteriol 2019; 201:JB.00077-19. [PMID: 31160400 DOI: 10.1128/jb.00077-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/30/2019] [Indexed: 11/20/2022] Open
Abstract
Picolinic acid (PA) is a natural toxic pyridine derivative. Microorganisms can degrade and utilize PA for growth. However, the full catabolic pathway of PA and its physiological and genetic foundation remain unknown. In this study, we identified a gene cluster, designated picRCEDFB4B3B2B1A1A2A3, responsible for the degradation of PA from Alcaligenes faecalis JQ135. Our results suggest that PA degradation pathway occurs as follows: PA was initially 6-hydroxylated to 6-hydroxypicolinic acid (6HPA) by PicA (a PA dehydrogenase). 6HPA was then 3-hydroxylated by PicB, a four-component 6HPA monooxygenase, to form 3,6-dihydroxypicolinic acid (3,6DHPA), which was then converted into 2,5-dihydroxypyridine (2,5DHP) by the decarboxylase PicC. 2,5DHP was further degraded to fumaric acid through PicD (2,5DHP 5,6-dioxygenase), PicE (N-formylmaleamic acid deformylase), PicF (maleamic acid amidohydrolase), and PicG (maleic acid isomerase). Homologous pic gene clusters with diverse organizations were found to be widely distributed in Alpha-, Beta-, and Gammaproteobacteria Our findings provide new insights into the microbial catabolism of environmental toxic pyridine derivatives.IMPORTANCE Picolinic acid is a common metabolite of l-tryptophan and some aromatic compounds and is an important intermediate in organic chemical synthesis. Although the microbial degradation/detoxification of picolinic acid has been studied for over 50 years, the underlying molecular mechanisms are still unknown. Here, we show that the pic gene cluster is responsible for the complete degradation of picolinic acid. The pic gene cluster was found to be widespread in other Alpha-, Beta-, and Gammaproteobacteria These findings provide a new perspective for understanding the catabolic mechanisms of picolinic acid in bacteria.
Collapse
|
39
|
Liao L, Su S, Zhao B, Fan C, Zhang J, Li H, Chen B. Biosynthetic Potential of a Novel Antarctic Actinobacterium Marisediminicola antarctica ZS314 T Revealed by Genomic Data Mining and Pigment Characterization. Mar Drugs 2019; 17:md17070388. [PMID: 31266176 PMCID: PMC6669644 DOI: 10.3390/md17070388] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 11/24/2022] Open
Abstract
Rare actinobacterial species are considered as potential resources of new natural products. Marisediminicola antarctica ZS314T is the only type strain of the novel actinobacterial genus Marisediminicola isolated from intertidal sediments in East Antarctica. The strain ZS314T was able to produce reddish orange pigments at low temperatures, showing characteristics of carotenoids. To understand the biosynthetic potential of this strain, the genome was completely sequenced for data mining. The complete genome had 3,352,609 base pairs (bp), much smaller than most genomes of actinomycetes. Five biosynthetic gene clusters (BGCs) were predicted in the genome, including a gene cluster responsible for the biosynthesis of C50 carotenoid, and four additional BGCs of unknown oligosaccharide, salinixanthin, alkylresorcinol derivatives, and NRPS (non-ribosomal peptide synthetase) or amino acid-derived compounds. Further experimental characterization indicated that the strain may produce C.p.450-like carotenoids, supporting the genomic data analysis. A new xanthorhodopsin gene was discovered along with the analysis of the salinixanthin biosynthetic gene cluster. Since little is known about this genus, this work improves our understanding of its biosynthetic potential and provides opportunities for further investigation of natural products and strategies for adaptation to the extreme Antarctic environment.
Collapse
Affiliation(s)
- Li Liao
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136, China.
| | - Shiyuan Su
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136, China
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Bin Zhao
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136, China
- School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Chengqi Fan
- Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Jin Zhang
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136, China
| | - Huirong Li
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136, China
| | - Bo Chen
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136, China.
| |
Collapse
|
40
|
Morrow KM, Tedford AR, Pankey MS, Lesser MP. A member of the Roseobacter clade, Octadecabacter sp., is the dominant symbiont in the brittle star Amphipholis squamata. FEMS Microbiol Ecol 2019; 94:4875921. [PMID: 29471328 DOI: 10.1093/femsec/fiy030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 02/16/2018] [Indexed: 12/31/2022] Open
Abstract
Symbiotic associations with subcuticular bacteria (SCB) have been identified and studied in many echinoderms, including the SCB of the brooding brittle star, Amphipholis squamata. Previous studies on the SCB of A. squamata placed the isolated bacterium, designated as AS1, in the genus Vibrio (Gammaproteobacteria), but subsequent studies suggested that the SCB of echinoderms belong to the Alphaproteobacteria. This study examines the taxonomic composition of SCB associated with A. squamata from the Northwest Atlantic using the 16S rRNA gene and next generation sequencing. Results show the presence of a single dominant bacterial type, within the Roseobacter clade, family Rhodobacteraceae, which composes 70%-80% of the A. squamata microbiome. These Rhodobacteraceae sequences were identified as members of the genus Octadecabacter. Additionally, the original isolate, AS1, from the brittle star A. squamata also belongs in the genus Octadecabacter based on Sanger sequencing of cloned 16S rRNA gene sequences. By comparison, adjacent seawater and sediment porewater communities were significantly more diverse, hosting bacteria in the phyla Proteobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia and Actinobacteria. Thus, a distinct SCB community is present in A. squamata that is dominated by a member of the genus Octadecabacter and is identical to the original isolate, AS1, from this brittle star.
Collapse
Affiliation(s)
- Kathleen M Morrow
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Abbey Rose Tedford
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - M Sabrina Pankey
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Michael P Lesser
- School of Marine Science and Ocean Engineering, University of New Hampshire, Durham, NH 03824, USA
| |
Collapse
|
41
|
Maccario L, Carpenter SD, Deming JW, Vogel TM, Larose C. Sources and selection of snow-specific microbial communities in a Greenlandic sea ice snow cover. Sci Rep 2019; 9:2290. [PMID: 30783153 PMCID: PMC6381142 DOI: 10.1038/s41598-019-38744-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/14/2018] [Indexed: 11/09/2022] Open
Abstract
Sea ice and its snow cover are critical for global processes including climate regulation and biogeochemical cycles. Despite an increase in studies focused on snow microorganisms, the ecology of snow inhabitants remains unclear. In this study, we investigated sources and selection of a snowpack-specific microbial community by comparing metagenomes from samples collected in a Greenlandic fjord within a vertical profile including atmosphere, snowpack with four distinct layers of snow, sea ice brine and seawater. Microbial communities in all snow layers derived from mixed sources, both marine and terrestrial, and were more similar to atmospheric communities than to sea ice or seawater communities. The surface snow metagenomes were characterized by the occurrence of genes involved in photochemical stress resistance, primary production and metabolism of diverse carbon sources. The basal saline snow layer that was in direct contact with the sea ice surface harbored a higher abundance of cells than the overlying snow layers, with a predominance of Alteromonadales and a higher relative abundance of marine representatives. However, the overall taxonomic structure of the saline layer was more similar to that of other snow layers and the atmosphere than to underlying sea ice and seawater. The expulsion of relatively nutrient-rich sea ice brine into basal snow might have stimulated the growth of copiotrophic psychro- and halotolerant snow members. Our study indicates that the size, composition and function of snowpack microbial communities over sea ice were influenced primarily by atmospheric deposition and inflow of sea ice brine and that they form a snow-specific assemblage reflecting the particular environmental conditions of the snowpack habitat.
Collapse
Affiliation(s)
- Lorrie Maccario
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France.
- Microbiology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | | | - Jody W Deming
- School of Oceanography, University of Washington, Seattle, USA
| | - Timothy M Vogel
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France
| | - Catherine Larose
- Environmental Microbial Genomics, Laboratoire Ampère, CNRS, École Centrale de Lyon, Écully, France
| |
Collapse
|
42
|
Psychrophilic lifestyles: mechanisms of adaptation and biotechnological tools. Appl Microbiol Biotechnol 2019; 103:2857-2871. [PMID: 30729286 DOI: 10.1007/s00253-019-09659-5] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 12/22/2022]
Abstract
Cold-adapted microorganisms inhabiting permanently low-temperature environments were initially just a biological curiosity but have emerged as rich sources of numerous valuable tools for application in a broad spectrum of innovative technologies. To overcome the multiple challenges inherent to life in their cold habitats, these microorganisms have developed a diverse array of highly sophisticated synergistic adaptations at all levels within their cells: from cell envelope and enzyme adaptation, to cryoprotectant and chaperone production, and novel metabolic capabilities. Basic research has provided valuable insights into how these microorganisms can thrive in their challenging habitat conditions and into the mechanisms of action of the various adaptive features employed, and such insights have served as a foundation for the knowledge-based development of numerous novel biotechnological tools. In this review, we describe the current knowledge of the adaptation strategies of cold-adapted microorganisms and the biotechnological perspectives and commercial tools emerging from this knowledge. Adaptive features and, where possible, applications, in relation to membrane fatty acids, membrane pigments, the cell wall peptidoglycan layer, the lipopolysaccharide component of the outer cell membrane, compatible solutes, antifreeze and ice-nucleating proteins, extracellular polymeric substances, biosurfactants, chaperones, storage materials such as polyhydroxyalkanoates and cyanophycins and metabolic adjustments are presented and discussed.
Collapse
|
43
|
Vargas-Albores F, Martínez-Córdova LR, Martínez-Porchas M, Calderón K, Lago-Lestón A. Functional metagenomics: a tool to gain knowledge for agronomic and veterinary sciences. Biotechnol Genet Eng Rev 2018; 35:69-91. [PMID: 30221593 DOI: 10.1080/02648725.2018.1513230] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The increased global demand for food production has motivated agroindustries to increase their own levels of production. Scientific efforts have contributed to improving these production systems, aiding to solve problems and establishing novel conceptual views and sustainable alternatives to cope with the increasing demand. Although microorganisms are key players in biological systems and may drive certain desired responses toward food production, little is known about the microbial communities that constitute the microbiomes associated with agricultural and veterinary activities. Understanding the diversity, structure and in situ interactions of microbes, together with how these interactions occur within microbial communities and with respect to their environments (including hosts), constitutes a major challenge with an enormous relevance for agriculture and biotechnology. The emergence of high-throughput sequencing technologies, together with novel and more accessible bioinformatics tools, has allowed researchers to learn more about the functional potential and functional activity of these microbial communities. These tools constitute a relevant approach for understanding the metabolic processes that can occur or are currently occurring in a given system and for implementing novel strategies focused on solving production problems or improving sustainability. Several 'omics' sciences and their applications in agriculture are discussed in this review, and the usage of functional metagenomics is proposed to achieve substantial advances for food agroindustries and veterinary sciences.
Collapse
Affiliation(s)
- Francisco Vargas-Albores
- a Centro de Investigación en Alimentación y Desarrollo , A.C. Coordinación de Tecnología de Alimentos de Origen Animal , Hermosillo , Mexico
| | - Luis R Martínez-Córdova
- b Departamento de Investigaciones Científicas y Tecnológicas de la Universidad de Sonora , Universidad de Sonora , Hermosillo , Mexico
| | - Marcel Martínez-Porchas
- a Centro de Investigación en Alimentación y Desarrollo , A.C. Coordinación de Tecnología de Alimentos de Origen Animal , Hermosillo , Mexico
| | - Kadiya Calderón
- b Departamento de Investigaciones Científicas y Tecnológicas de la Universidad de Sonora , Universidad de Sonora , Hermosillo , Mexico
| | | |
Collapse
|
44
|
Anashkin VA, Bertsova YV, Mamedov AM, Mamedov MD, Arutyunyan AM, Baykov AA, Bogachev AV. Engineering a carotenoid-binding site in Dokdonia sp. PRO95 Na +-translocating rhodopsin by a single amino acid substitution. PHOTOSYNTHESIS RESEARCH 2018; 136:161-169. [PMID: 28983723 DOI: 10.1007/s11120-017-0453-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/29/2017] [Indexed: 06/07/2023]
Abstract
Light-driven H+, Cl- and Na+ rhodopsin pumps all use a covalently bound retinal molecule to capture light energy. Some H+-pumping rhodopsins (xanthorhodopsins; XRs) additionally contain a carotenoid antenna for light absorption. Comparison of the available primary and tertiary structures of rhodopsins pinpointed a single Thr residue (Thr216) that presumably prevents carotenoid binding to Na+-pumping rhodopsins (NaRs). We replaced this residue in Dokdonia sp. PRO95 NaR with Gly, which is found in the corresponding position in XRs, and produced a variant rhodopsin in a ketocarotenoid-synthesising Escherichia coli strain. Unlike wild-type NaR, the isolated variant protein contained the tightly bound carotenoids canthaxanthin and echinenone. These carotenoids were visible in the absorption, circular dichroism and fluorescence excitation spectra of the Thr216Gly-substituted NaR, which indicates their function as a light-harvesting antenna. The amino acid substitution and the bound carotenoids did not affect the NaR photocycle. Our findings suggest that the antenna function was recently lost during NaR evolution but can be easily restored by site-directed mutagenesis.
Collapse
Affiliation(s)
- Viktor A Anashkin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Yulia V Bertsova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Adalyat M Mamedov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Mahir D Mamedov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Alexander M Arutyunyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Alexander A Baykov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Alexander V Bogachev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234.
| |
Collapse
|
45
|
Vader A, Laughinghouse HD, Griffiths C, Jakobsen KS, Gabrielsen TM. Proton-pumping rhodopsins are abundantly expressed by microbial eukaryotes in a high-Arctic fjord. Environ Microbiol 2018; 20:890-902. [PMID: 29266690 DOI: 10.1111/1462-2920.14035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 11/21/2017] [Accepted: 12/18/2017] [Indexed: 01/07/2023]
Abstract
Proton-pumping rhodopsins provide an alternative pathway to photosynthesis by which solar energy can enter the marine food web. Rhodopsin genes are widely found in marine bacteria, also in the Arctic, and were recently reported from several eukaryotic lineages. So far, little is known about rhodopsin expression in Arctic eukaryotes. In this study, we used metatranscriptomics and 18S rDNA tag sequencing to examine the mid-summer function and composition of marine protists (size 0.45-10 µm) in the high-Arctic Billefjorden (Spitsbergen), especially focussing on the expression of microbial proton-pumping rhodopsins. Rhodopsin transcripts were highly abundant, at a level similar to that of genes involved in photosynthesis. Phylogenetic analyses placed the environmental rhodopsins within disparate eukaryotic lineages, including dinoflagellates, stramenopiles, haptophytes and cryptophytes. Sequence comparison indicated the presence of several functional types, including xanthorhodopsins and a eukaryotic clade of proteorhodopsin. Transcripts belonging to the proteorhodopsin clade were also abundant in published metatranscriptomes from other oceanic regions, suggesting a global distribution. The diversity and abundance of rhodopsins show that these light-driven proton pumps play an important role in Arctic microbial eukaryotes. Understanding this role is imperative to predicting the future of the Arctic marine ecosystem faced by a changing light climate due to diminishing sea-ice.
Collapse
Affiliation(s)
- Anna Vader
- University Centre in Svalbard, Longyearbyen, Norway
| | | | | | - Kjetill S Jakobsen
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Norway
| | | |
Collapse
|
46
|
Kopejtka K, Tomasch J, Zeng Y, Tichý M, Sorokin DY, Koblížek M. Genomic Analysis of the Evolution of Phototrophy among Haloalkaliphilic Rhodobacterales. Genome Biol Evol 2017; 9:1950-1962. [PMID: 28810712 PMCID: PMC5553392 DOI: 10.1093/gbe/evx141] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2017] [Indexed: 11/12/2022] Open
Abstract
A characteristic feature of the order Rhodobacterales is the presence of a large number of photoautotrophic and photoheterotrophic species containing bacteriochlorophyll. Interestingly, these phototrophic species are phylogenetically mixed with chemotrophs. To better understand the origin of such variability, we sequenced the genomes of three closely related haloalkaliphilic species, differing in their phototrophic capacity and oxygen preference: the photoheterotrophic and facultatively anaerobic bacterium Rhodobaca barguzinensis, aerobic photoheterotroph Roseinatronobacter thiooxidans, and aerobic heterotrophic bacterium Natronohydrobacter thiooxidans. These three haloalcaliphilic species are phylogenetically related and share many common characteristics with the Rhodobacter species, forming together the Rhodobacter-Rhodobaca (RR) group. A comparative genomic analysis showed close homology of photosynthetic proteins and similarity in photosynthesis gene organization among the investigated phototrophic RR species. On the other hand, Rhodobaca barguzinensis and Roseinatronobacter thiooxidans lack an inorganic carbon fixation pathway and outer light-harvesting genes. This documents the reduction of their photosynthetic machinery towards a mostly photoheterotrophic lifestyle. Moreover, both phototrophic species contain 5-aminolevulinate synthase (encoded by the hemA gene) incorporated into their photosynthesis gene clusters, which seems to be a common feature of all aerobic anoxygenic phototrophic Alphaproteobacteria. Interestingly, the chrR-rpoE (sigma24) operon, which is part of singlet oxygen defense in phototrophic species, was found in the heterotrophic strain Natronohydrobacter thiooxidans. This suggests that this organism evolved from a photoheterotrophic ancestor through the loss of its photosynthesis genes. The overall evolution of phototrophy among the haloalkaliphilic members of the RR group is discussed.
Collapse
Affiliation(s)
- Karel Kopejtka
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology, CAS, Center Algatech, Třeboň, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jürgen Tomasch
- Research Group Microbial Communication, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Yonghui Zeng
- Aarhus Institute of Advanced Studies, Aarhus, Denmark
| | - Martin Tichý
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology, CAS, Center Algatech, Trebon, Czech Republic
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia.,Department of Biotechnology, Delft University of Technology, The Netherlands
| | - Michal Koblížek
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology, CAS, Center Algatech, Třeboň, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| |
Collapse
|
47
|
Simon M, Scheuner C, Meier-Kolthoff JP, Brinkhoff T, Wagner-Döbler I, Ulbrich M, Klenk HP, Schomburg D, Petersen J, Göker M. Phylogenomics of Rhodobacteraceae reveals evolutionary adaptation to marine and non-marine habitats. THE ISME JOURNAL 2017; 11:1483-1499. [PMID: 28106881 PMCID: PMC5437341 DOI: 10.1038/ismej.2016.198] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/29/2016] [Accepted: 11/19/2016] [Indexed: 12/31/2022]
Abstract
Marine Rhodobacteraceae (Alphaproteobacteria) are key players of biogeochemical cycling, comprise up to 30% of bacterial communities in pelagic environments and are often mutualists of eukaryotes. As 'Roseobacter clade', these 'roseobacters' are assumed to be monophyletic, but non-marine Rhodobacteraceae have not yet been included in phylogenomic analyses. Therefore, we analysed 106 genome sequences, particularly emphasizing gene sampling and its effect on phylogenetic stability, and investigated relationships between marine versus non-marine habitat, evolutionary origin and genomic adaptations. Our analyses, providing no unequivocal evidence for the monophyly of roseobacters, indicate several shifts between marine and non-marine habitats that occurred independently and were accompanied by characteristic changes in genomic content of orthologs, enzymes and metabolic pathways. Non-marine Rhodobacteraceae gained high-affinity transporters to cope with much lower sulphate concentrations and lost genes related to the reduced sodium chloride and organohalogen concentrations in their habitats. Marine Rhodobacteraceae gained genes required for fucoidan desulphonation and synthesis of the plant hormone indole 3-acetic acid and the compatible solutes ectoin and carnitin. However, neither plasmid composition, even though typical for the family, nor the degree of oligotrophy shows a systematic difference between marine and non-marine Rhodobacteraceae. We suggest the operational term 'Roseobacter group' for the marine Rhodobacteraceae strains.
Collapse
Affiliation(s)
- Meinhard Simon
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Carmen Scheuner
- Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Jan P Meier-Kolthoff
- Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Thorsten Brinkhoff
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Irene Wagner-Döbler
- Helmholtz Centre for Infection Research, Research Group Microbial Communication, Braunschweig, Germany
| | - Marcus Ulbrich
- Institute of Biochemical Engineering, Technical University Braunschweig, Braunschweig, Germany
| | - Hans-Peter Klenk
- School of Biology, Newcastle University, Newcastle upon Tyne, UK
| | - Dietmar Schomburg
- Institute of Biochemical Engineering, Technical University Braunschweig, Braunschweig, Germany
| | - Jörn Petersen
- Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Markus Göker
- Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| |
Collapse
|
48
|
Genome Sequence of Rhodoferax antarcticus ANT.BR T; A Psychrophilic Purple Nonsulfur Bacterium from an Antarctic Microbial Mat. Microorganisms 2017; 5:microorganisms5010008. [PMID: 28230808 PMCID: PMC5374385 DOI: 10.3390/microorganisms5010008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/16/2017] [Accepted: 02/18/2017] [Indexed: 12/23/2022] Open
Abstract
Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anoxygenic phototroph that grows best below 20 °C. We present here a high-quality draft genome of Rfx. antarcticus strain ANT.BRT, isolated from an Antarctic microbial mat. The circular chromosome (3.8 Mbp) of Rfx. antarcticus has a 59.1% guanine + cytosine (GC) content and contains 4036 open reading frames. In addition, the bacterium contains a sizable plasmid (198.6 kbp, 48.4% GC with 226 open reading frames) that comprises about 5% of the total genetic content. Surprisingly, genes encoding light-harvesting complexes 1 and 3 (LH1 and LH3), but not light-harvesting complex 2 (LH2), were identified in the photosynthesis gene cluster of the Rfx. antarcticus genome, a feature that is unique among purple phototrophs. Consistent with physiological studies that showed a strong capacity for nitrogen fixation in Rfx. antarcticus, a nitrogen fixation gene cluster encoding a molybdenum-type nitrogenase was present, but no alternative nitrogenases were identified despite the cold-active phenotype of this phototroph. Genes encoding two forms of ribulose 1,5-bisphosphate carboxylase/oxygenase were present in the Rfx. antarcticus genome, a feature that likely provides autotrophic flexibility under varying environmental conditions. Lastly, genes for assembly of both type IV pili and flagella are present, with the latter showing an unusual degree of clustering. This report represents the first genomic analysis of a psychrophilic anoxygenic phototroph and provides a glimpse of the genetic basis for maintaining a phototrophic lifestyle in a permanently cold, yet highly variable, environment.
Collapse
|
49
|
Nakamura S, Kikukawa T, Tamogami J, Kamiya M, Aizawa T, Hahn MW, Ihara K, Kamo N, Demura M. Photochemical characterization of actinorhodopsin and its functional existence in the natural host. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1900-1908. [PMID: 27659506 DOI: 10.1016/j.bbabio.2016.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 09/13/2016] [Accepted: 09/17/2016] [Indexed: 11/29/2022]
Abstract
Actinorhodopsin (ActR) is a light-driven outward H+ pump. Although the genes of ActRs are widely spread among freshwater bacterioplankton, there are no prior data on their functional expression in native cell membranes. Here, we demonstrate ActR phototrophy in the native actinobacterium. Genome analysis showed that Candidatus Rhodoluna planktonica, a freshwater actinobacterium, encodes one microbial rhodopsin (RpActR) belonging to the ActR family. Reflecting the functional expression of RpActR, illumination induced the acidification of the actinobacterial cell suspension and then elevated the ATP content inside the cells. The photochemistry of RpActR was also examined using heterologously expressed RpActR in Escherichia coli membranes. The purified RpActR showed λmax at 534nm and underwent a photocycle characterized by the very fast formation of M intermediate. The subsequent intermediate, named P620, could be assigned to the O intermediate in other H+ pumps. In contrast to conventional O, the accumulation of P620 remains prominent, even at high pH. Flash-induced absorbance changes suggested that there exists only one kind of photocycle at any pH. However, above pH7, RpActR shows heterogeneity in the H+ transfer sequences: one first captures H+ and then releases it during the formation and decay of P620, while the other first releases H+ prior to H+ uptake during P620 formation.
Collapse
Affiliation(s)
- Shintaro Nakamura
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Takashi Kikukawa
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan.
| | - Jun Tamogami
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Japan
| | - Masakatsu Kamiya
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Tomoyasu Aizawa
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Martin W Hahn
- Research Institute for Limnology, University of Innsbruck, Mondsee, Austria
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | - Naoki Kamo
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Makoto Demura
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| |
Collapse
|
50
|
Reynolds D, Thomas T. Evolution and function of eukaryotic-like proteins from sponge symbionts. Mol Ecol 2016; 25:5242-5253. [PMID: 27543954 DOI: 10.1111/mec.13812] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 08/08/2016] [Accepted: 08/18/2016] [Indexed: 12/25/2022]
Abstract
Sponges (Porifera) are ancient metazoans that harbour diverse microorganisms, whose symbiotic interactions are essential for the host's health and function. Although symbiosis between bacteria and sponges are ubiquitous, the molecular mechanisms that control these associations are largely unknown. Recent (meta-) genomic analyses discovered an abundance of genes encoding for eukaryotic-like proteins (ELPs) in bacterial symbionts from different sponge species. ELPs belonging to the ankyrin repeat (AR) class from a bacterial symbiont of the sponge Cymbastela concentrica were subsequently found to modulate amoebal phagocytosis. This might be a molecular mechanism, by which symbionts can control their interaction with the sponge. In this study, we investigated the evolution and function of ELPs from other classes and from symbionts found in other sponges to better understand the importance of ELPs for bacteria-eukaryote interactions. Phylogenetic analyses showed that all of the nine ELPs investigated were most closely related to proteins found either in eukaryotes or in bacteria that can live in association with eukaryotes. ELPs were then recombinantly expressed in Escherichia coli and exposed to the amoeba Acanthamoeba castellanii, which is functionally analogous to phagocytic cells in sponges. Phagocytosis assays with E. coli containing three ELP classes (AR, TPR-SEL1 and NHL) showed a significantly higher percentage of amoeba containing bacteria and average number of intracellular bacteria per amoeba when compared to negative controls. The result that various classes of ELPs found in symbionts of different sponges can modulate phagocytosis indicates that they have a broader function in mediating bacteria-sponge interactions.
Collapse
Affiliation(s)
- David Reynolds
- Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Torsten Thomas
- Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
| |
Collapse
|