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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.
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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
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NASA’s MODIS/VIIRS Global Water Reservoir Product Suite from Moderate Resolution Remote Sensing Data. REMOTE SENSING 2021. [DOI: 10.3390/rs13040565] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Global reservoir information can not only benefit local water management but can also improve our understanding of the hydrological cycle. This information includes water area, elevation, and storage; evaporation rate and volume values; and other characteristics. However, operational wall-to-wall reservoir storage and evaporation monitoring information is lacking on a global scale. Here we introduce NASA’s new MODIS/VIIRS Global Water Reservoir product suite based on moderate resolution remote sensing data—the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Visible Infrared Imaging Radiometer Suite (VIIRS). This product consists of 8-day (MxD28C2 and VNP28C2) and monthly (MxD28C3 and VNP28C3) measurements for 164 large reservoirs (MxD stands for the product from both Terra (MOD) or Aqua (MYD) satellites). The 8-day product provides area, elevation, and storage values, which were generated by first extracting water areas from surface reflectance data and then applying the area estimations to the pre-established Area–Elevation (A–E) relationships. These values were then further aggregated to monthly, with the evaporation rate and volume information added. The evaporation rate and volume values were calculated after the Lake Temperature and Evaporation Model (LTEM) using MODIS/VIIRS land surface temperature product and meteorological data from the Global Land Data Assimilation System (GLDAS). Validation results show that the 250 m area classifications from MODIS agree well with the high-resolution classifications from Landsat (R2 = 0.99). Validation of elevation and storage products for twelve Indian reservoirs show good agreement in terms of R2 values (0.71–0.96 for elevation, and 0.79–0.96 for storage) and normalized root-mean-square error (NRMSE) values (5.08–19.34% for elevation, and 6.39–18.77% for storage). The evaporation rate results for two reservoirs (Lake Nasser and Lake Mead) agree well with in situ measurements (R2 values of 0.61 and 0.66, and NRMSE values of 16.25% and 21.76%). Furthermore, preliminary results from the VIIRS reservoir product have shown good consistency with the MODIS based product, confirming the continuity of this 20-year product suite. This new global water reservoir product suite can provide valuable information with regard to water-sources-related studies, applications, management, and hydrological modeling and change analysis such as drought monitoring.
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DeLong EF. Genome-enabled exploration of microbial ecology and evolution in the sea: a rising tide lifts all boats. Environ Microbiol 2021; 23:1301-1321. [PMID: 33459471 PMCID: PMC8049014 DOI: 10.1111/1462-2920.15403] [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: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 11/26/2022]
Abstract
As a young bacteriologist just launching my career during the early days of the 'microbial revolution' in the 1980s, I was fortunate to participate in some early discoveries, and collaborate in the development of cross-disciplinary methods now commonly referred to as "metagenomics". My early scientific career focused on applying phylogenetic and genomic approaches to characterize 'wild' bacteria, archaea and viruses in their natural habitats, with an emphasis on marine systems. These central interests have not changed very much for me over the past three decades, but knowledge, methodological advances and new theoretical perspectives about the microbial world certainly have. In this invited 'How we did it' perspective, I trace some of the trajectories of my lab's collective efforts over the years, including phylogenetic surveys of microbial assemblages in marine plankton and sediments, development of microbial community gene- and genome-enabled surveys, and application of genome-guided, cultivation-independent functional characterization of novel enzymes, pathways and their relationships to in situ biogeochemistry. Throughout this short review, I attempt to acknowledge, all the mentors, students, postdocs and collaborators who enabled this research. Inevitably, a brief autobiographical review like this cannot be fully comprehensive, so sincere apologies to any of my great colleagues who are not explicitly mentioned herein. I salute you all as well!
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Affiliation(s)
- Edward F DeLong
- Daniel K. Inouye Centre for Microbial Oceanography: Research and Education, University of Hawaii, Manoa, Honolulu, HI, 96822, USA
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Abstract
The ocean’s “biological pump” exports sinking particles containing carbon, nutrients, and energy to the deep sea, contributing centrally to the global carbon cycle. Here, we identify key organisms and biological processes associated with elevated carbon flux to the abyss. Our analyses reveal that, during summer export, specific populations of photosynthetic algae, heterotrophic protists, and bacteria reach the abyss on sinking particles. Deep-sea bacteria respond rapidly to this elevated nutrient delivery to the abyss in summer. During other seasons, different organisms and processes appear responsible for particle export to the deep sea. Our analyses reveal key biota and biological processes that interconnect surface productivity, particle export, and the deep-sea ecosystem, thereby influencing the function and efficiency of the ocean’s biological pump. In the open ocean, elevated carbon flux (ECF) events increase the delivery of particulate carbon from surface waters to the seafloor by severalfold compared to other times of year. Since microbes play central roles in primary production and sinking particle formation, they contribute greatly to carbon export to the deep sea. Few studies, however, have quantitatively linked ECF events with the specific microbial assemblages that drive them. Here, we identify key microbial taxa and functional traits on deep-sea sinking particles that correlate positively with ECF events. Microbes enriched on sinking particles in summer ECF events included symbiotic and free-living diazotrophic cyanobacteria, rhizosolenid diatoms, phototrophic and heterotrophic protists, and photoheterotrophic and copiotrophic bacteria. Particle-attached bacteria reaching the abyss during summer ECF events encoded metabolic pathways reflecting their surface water origins, including oxygenic and aerobic anoxygenic photosynthesis, nitrogen fixation, and proteorhodopsin-based photoheterotrophy. The abundances of some deep-sea bacteria also correlated positively with summer ECF events, suggesting rapid bathypelagic responses to elevated organic matter inputs. Biota enriched on sinking particles during a spring ECF event were distinct from those found in summer, and included rhizaria, copepods, fungi, and different bacterial taxa. At other times over our 3-y study, mid- and deep-water particle colonization, predation, degradation, and repackaging (by deep-sea bacteria, protists, and animals) appeared to shape the biotic composition of particles reaching the abyss. Our analyses reveal key microbial players and biological processes involved in particle formation, rapid export, and consumption, that may influence the ocean’s biological pump and help sustain deep-sea ecosystems.
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DeLong EF. Exploring Marine Planktonic Archaea: Then and Now. Front Microbiol 2021; 11:616086. [PMID: 33519774 PMCID: PMC7838436 DOI: 10.3389/fmicb.2020.616086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/18/2020] [Indexed: 12/24/2022] Open
Abstract
In 1977, Woese and Fox leveraged molecular phylogenetic analyses of ribosomal RNAs and identified a new microbial domain of life on Earth, the Archaebacteria (now known as Archaea). At the time of their discovery, only one archaebacterial group, the strictly anaerobic methanogens, was known. But soon, other phenotypically unrelated microbial isolates were shown to belong to the Archaea, many originating from extreme habitats, including extreme halophiles, extreme thermophiles, and thermoacidophiles. Since most Archaea seemed to inhabit extreme or strictly anoxic habitats, it came as a surprise in 1992 when two new lineages of archaea were reported to be abundant in oxygen rich, temperate marine coastal waters and the deep ocean. Since that time, studies of marine planktonic archaea have revealed many more surprises, including their unexpected ubiquity, unusual symbiotic associations, unpredicted physiologies and biogeochemistry, and global abundance. In this Perspective, early work conducted on marine planktonic Archaea by my lab group and others is discussed in terms of the relevant historical context, some of the original research motivations, and surprises and discoveries encountered along the way.
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Affiliation(s)
- Edward F DeLong
- Daniel K. Inouye Center for Microbial Oceanography Research and Education, University of Hawai'i at Mănoa, Honolulu, HI, United States
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Inoue K. Diversity, Mechanism, and Optogenetic Application of Light-Driven Ion Pump Rhodopsins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:89-126. [PMID: 33398809 DOI: 10.1007/978-981-15-8763-4_6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ion-transporting microbial rhodopsins are widely used as major molecular tools in optogenetics. They are categorized into light-gated ion channels and light-driven ion pumps. While the former passively transport various types of cations and anions in a light-dependent manner, light-driven ion pumps actively transport specific ions, such as H+, Na+, Cl-, against electrophysiological potential by using light energy. Since the ion transport by these pumps induces hyperpolarization of membrane potential and inhibit neural firing, light-driven ion-pumping rhodopsins are mostly applied as inhibitory optogenetics tools. Recent progress in genome and metagenome sequencing identified more than several thousands of ion-pumping rhodopsins from a wide variety of microbes, and functional characterization studies has been revealing many new types of light-driven ion pumps one after another. Since light-gated channels were reviewed in other chapters in this book, here the rapid progress in functional characterization, molecular mechanism study, and optogenetic application of ion-pumping rhodopsins were reviewed.
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Affiliation(s)
- Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Chiba, Japan.
- PRESTO, Japan Science and Technology Agency, Saitama, Japan.
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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: 12] [Impact Index Per Article: 3.0] [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.
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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
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Konno M, Yamauchi Y, Inoue K, Kandori H. Expression analysis of microbial rhodopsin-like genes in Guillardia theta. PLoS One 2020; 15:e0243387. [PMID: 33270796 PMCID: PMC7714340 DOI: 10.1371/journal.pone.0243387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/19/2020] [Indexed: 12/28/2022] Open
Abstract
The Cryptomonad Guillardia theta has 42 genes encoding microbial rhodopsin-like proteins in their genomes. Light-driven ion-pump activity has been reported for some rhodopsins based on heterologous E. coli or mammalian cell expression systems. However, neither their physiological roles nor the expression of those genes in native cells are known. To reveal their physiological roles, we investigated the expression patterns of these genes under various growth conditions. Nitrogen (N) deficiency induced color change in exponentially growing G. theta cells from brown to green. The 29 rhodopsin-like genes were expressed in native cells. We found that the expression of 6 genes was induced under N depletion, while that of another 6 genes was reduced under N depletion.
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Affiliation(s)
- Masae Konno
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
- * E-mail: (HK); (MK)
| | - Yumeka Yamauchi
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Keiichi Inoue
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
| | - Hideki Kandori
- Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
- * E-mail: (HK); (MK)
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Kozlova MI, Bushmakin IM, Belyaeva JD, Shalaeva DN, Dibrova DV, Cherepanov DA, Mulkidjanian AY. Expansion of the "Sodium World" through Evolutionary Time and Taxonomic Space. BIOCHEMISTRY. BIOKHIMIIA 2020; 85:1518-1542. [PMID: 33705291 DOI: 10.1134/s0006297920120056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In 1986, Vladimir Skulachev and his colleagues coined the term "Sodium World" for the group of diverse organisms with sodium (Na)-based bioenergetics. Albeit only few such organisms had been discovered by that time, the authors insightfully noted that "the great taxonomic variety of organisms employing the Na-cycle points to the ubiquitous distribution of this novel type of membrane-linked energy transductions". Here we used tools of bioinformatics to follow expansion of the Sodium World through the evolutionary time and taxonomic space. We searched for those membrane protein families in prokaryotic genomes that correlate with the use of the Na-potential for ATP synthesis by different organisms. In addition to the known Na-translocators, we found a plethora of uncharacterized protein families; most of them show no homology with studied proteins. In addition, we traced the presence of Na-based energetics in many novel archaeal and bacterial clades, which were recently identified by metagenomic techniques. The data obtained support the view that the Na-based energetics preceded the proton-dependent energetics in evolution and prevailed during the first two billion years of the Earth history before the oxygenation of atmosphere. Hence, the full capacity of Na-based energetics in prokaryotes remains largely unexplored. The Sodium World expanded owing to the acquisition of new functions by Na-translocating systems. Specifically, most classes of G-protein-coupled receptors (GPCRs), which are targeted by almost half of the known drugs, appear to evolve from the Na-translocating microbial rhodopsins. Thereby the GPCRs of class A, with 700 representatives in human genome, retained the Na-binding site in the center of the transmembrane heptahelical bundle together with the capacity of Na-translocation. Mathematical modeling showed that the class A GPCRs could use the energy of transmembrane Na-potential for increasing both their sensitivity and selectivity. Thus, GPCRs, the largest protein family coded by human genome, stem from the Sodium World, which encourages exploration of other Na-dependent enzymes of eukaryotes.
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Affiliation(s)
- M I Kozlova
- School of Physics, Osnabrueck University, Osnabrueck, 49069, Germany. .,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - I M Bushmakin
- School of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119992, Russia.
| | - J D Belyaeva
- School of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119992, Russia.
| | - D N Shalaeva
- School of Physics, Osnabrueck University, Osnabrueck, 49069, Germany.
| | - D V Dibrova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
| | - D A Cherepanov
- Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, 119991, Russia.
| | - A Y Mulkidjanian
- School of Physics, Osnabrueck University, Osnabrueck, 49069, Germany. .,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.,School of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119992, Russia
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Lokiarchaeota archaeon schizorhodopsin-2 (LaSzR2) is an inward proton pump displaying a characteristic feature of acid-induced spectral blue-shift. Sci Rep 2020; 10:20857. [PMID: 33257762 PMCID: PMC7704677 DOI: 10.1038/s41598-020-77936-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/29/2020] [Indexed: 11/25/2022] Open
Abstract
The photoreactive protein rhodopsin is widespread in microorganisms and has a variety of photobiological functions. Recently, a novel phylogenetically distinctive group named ‘schizorhodopsin (SzR)’ has been identified as an inward proton pump. We performed functional and spectroscopic studies on an uncharacterised schizorhodopsin from the phylum Lokiarchaeota archaeon. The protein, LaSzR2, having an all-trans-retinal chromophore, showed inward proton pump activity with an absorption maximum at 549 nm. The pH titration experiments revealed that the protonated Schiff base of the retinal chromophore (Lys188, pKa = 12.3) is stabilised by the deprotonated counterion (presumably Asp184, pKa = 3.7). The flash-photolysis experiments revealed the presence of two photointermediates, K and M. A proton was released and uptaken from bulk solution upon the formation and decay of the M intermediate. During the M-decay, the Schiff base was reprotonated by the proton from a proton donating residue (presumably Asp172). These properties were compared with other inward (SzRs and xenorhodopsins, XeRs) and outward proton pumps. Notably, LaSzR2 showed acid-induced spectral ‘blue-shift’ due to the protonation of the counterion, whereas outward proton pumps showed opposite shifts (red-shifts). Thus, we can distinguish between inward and outward proton pumps by the direction of the acid-induced spectral shift.
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Biswal DP, Panigrahi KCS. Light- and hormone-mediated development in non-flowering plants: An overview. PLANTA 2020; 253:1. [PMID: 33245411 DOI: 10.1007/s00425-020-03501-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Light, hormones and their interaction regulate different aspects of development in non-flowering plants. They might have played a role in the evolution of different plant groups by conferring specific adaptive evolutionary changes. Plants are sessile organisms. Unlike animals, they lack the opportunity to abandon their habitat in unfavorable conditions. They respond to different environmental cues and adapt accordingly to control their growth and developmental pattern. While phytohormones are known to be internal regulators of plant development, light is a major environmental signal that shapes plant processes. It is plausible that light-hormone crosstalk might have played an important role in plant evolution. But how the crosstalk between light and phytohormone signaling pathways might have shaped the plant evolution is unclear. One of the possible reasons is that flowering plants have been studied extensively in context of plant development, which cannot serve the purpose of evolutionary comparisons. In order to elucidate the role of light, hormone and their crosstalk in the evolutionary adaptation in plant kingdom, one needs to understand various light- and hormone-mediated processes in diverse non-flowering plants. This review is an attempt to outline major light- and phytohormone-mediated responses in non-flowering plant groups such as algae, bryophytes, pteridophytes and gymnosperms.
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Affiliation(s)
- Durga Prasad Biswal
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha, India
- Homi Bhabha National Institute (HBNI), Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Kishore Chandra Sekhar Panigrahi
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha, India.
- Homi Bhabha National Institute (HBNI), Training School Complex, Anushakti Nagar, Mumbai, 400094, India.
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Abstract
Over the course of evolution for billions of years, bacteria that are capable of light-driven energy production have occupied every corner of surface Earth where sunlight can reach. Only two general biological systems have evolved in bacteria to be capable of net energy conservation via light harvesting: one is based on the pigment of (bacterio-)chlorophyll and the other is based on proton-pumping rhodopsin. There is emerging genomic evidence that these two rather different systems can coexist in a single bacterium to take advantage of their contrasting characteristics in the number of genes involved, biosynthesis cost, ease of expression control, and efficiency of energy production and thus enhance the capability of exploiting solar energy. Our data provide the first clear-cut evidence that such dual phototrophy potentially exists in glacial bacteria. Further public genome mining suggests this understudied dual phototrophic mechanism is possibly more common than our data alone suggested. Conserving additional energy from sunlight through bacteriochlorophyll (BChl)-based reaction center or proton-pumping rhodopsin is a highly successful life strategy in environmental bacteria. BChl and rhodopsin-based systems display contrasting characteristics in the size of coding operon, cost of biosynthesis, ease of expression control, and efficiency of energy production. This raises an intriguing question of whether a single bacterium has evolved the ability to perform these two types of phototrophy complementarily according to energy needs and environmental conditions. Here, we report four Tardiphaga sp. strains (Alphaproteobacteria) of monophyletic origin isolated from a high Arctic glacier in northeast Greenland (81.566° N, 16.363° W) that are at different evolutionary stages concerning phototrophy. Their >99.8% identical genomes contain footprints of horizontal operon transfer (HOT) of the complete gene clusters encoding BChl- and xanthorhodopsin (XR)-based dual phototrophy. Two strains possess only a complete XR operon, while the other two strains have both a photosynthesis gene cluster and an XR operon in their genomes. All XR operons are heavily surrounded by mobile genetic elements and are located close to a tRNA gene, strongly signaling that a HOT event of the XR operon has occurred recently. Mining public genome databases and our high Arctic glacial and soil metagenomes revealed that phylogenetically diverse bacteria have the metabolic potential of performing BChl- and rhodopsin-based dual phototrophy. Our data provide new insights on how bacteria cope with the harsh and energy-deficient environment in surface glacier, possibly by maximizing the capability of exploiting solar energy.
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Broser M, Spreen A, Konold PE, Schiewer E, Adam S, Borin V, Schapiro I, Seifert R, Kennis JTM, Bernal Sierra YA, Hegemann P. NeoR, a near-infrared absorbing rhodopsin. Nat Commun 2020; 11:5682. [PMID: 33173168 PMCID: PMC7655827 DOI: 10.1038/s41467-020-19375-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 10/06/2020] [Indexed: 12/18/2022] Open
Abstract
The Rhizoclosmatium globosum genome encodes three rhodopsin-guanylyl cyclases (RGCs), which are predicted to facilitate visual orientation of the fungal zoospores. Here, we show that RGC1 and RGC2 function as light-activated cyclases only upon heterodimerization with RGC3 (NeoR). RGC1/2 utilize conventional green or blue-light-sensitive rhodopsins (λmax = 550 and 480 nm, respectively), with short-lived signaling states, responsible for light-activation of the enzyme. The bistable NeoR is photoswitchable between a near-infrared-sensitive (NIR, λmax = 690 nm) highly fluorescent state (QF = 0.2) and a UV-sensitive non-fluorescent state, thereby modulating the activity by NIR pre-illumination. No other rhodopsin has been reported so far to be functional as a heterooligomer, or as having such a long wavelength absorption or high fluorescence yield. Site-specific mutagenesis and hybrid quantum mechanics/molecular mechanics simulations support the idea that the unusual photochemical properties result from the rigidity of the retinal chromophore and a unique counterion triad composed of two glutamic and one aspartic acids. These findings substantially expand our understanding of the natural potential and limitations of spectral tuning in rhodopsin photoreceptors.
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Affiliation(s)
- Matthias Broser
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
| | - Anika Spreen
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Patrick E Konold
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Enrico Schiewer
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Suliman Adam
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Veniamin Borin
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Reinhard Seifert
- Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - John T M Kennis
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | | | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
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64
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Besaw JE, Ou WL, Morizumi T, Eger BT, Sanchez Vasquez JD, Chu JHY, Harris A, Brown LS, Miller RJD, Ernst OP. The crystal structures of a chloride-pumping microbial rhodopsin and its proton-pumping mutant illuminate proton transfer determinants. J Biol Chem 2020; 295:14793-14804. [PMID: 32703899 DOI: 10.1074/jbc.ra120.014118] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/14/2020] [Indexed: 01/25/2023] Open
Abstract
Microbial rhodopsins are versatile and ubiquitous retinal-binding proteins that function as light-driven ion pumps, light-gated ion channels, and photosensors, with potential utility as optogenetic tools for altering membrane potential in target cells. Insights from crystal structures have been central for understanding proton, sodium, and chloride transport mechanisms of microbial rhodopsins. Two of three known groups of anion pumps, the archaeal halorhodopsins (HRs) and bacterial chloride-pumping rhodopsins, have been structurally characterized. Here we report the structure of a representative of a recently discovered third group consisting of cyanobacterial chloride and sulfate ion-pumping rhodopsins, the Mastigocladopsis repens rhodopsin (MastR). Chloride-pumping MastR contains in its ion transport pathway a unique Thr-Ser-Asp (TSD) motif, which is involved in the binding of a chloride ion. The structure reveals that the chloride-binding mode is more similar to HRs than chloride-pumping rhodopsins, but the overall structure most closely resembles bacteriorhodopsin (BR), an archaeal proton pump. The MastR structure shows a trimer arrangement reminiscent of BR-like proton pumps and shows features at the extracellular side more similar to BR than the other chloride pumps. We further solved the structure of the MastR-T74D mutant, which contains a single amino acid replacement in the TSD motif. We provide insights into why this point mutation can convert the MastR chloride pump into a proton pump but cannot in HRs. Our study points at the importance of precise coordination and exact location of the water molecule in the active center of proton pumps, which serves as a bridge for the key proton transfer.
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Affiliation(s)
- Jessica E Besaw
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Wei-Lin Ou
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Takefumi Morizumi
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Bryan T Eger
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Juan D Sanchez Vasquez
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Jessica H Y Chu
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Harris
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Leonid S Brown
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - R J Dwayne Miller
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada; Department of Physics, University of Toronto, Toronto, Ontario, Canada
| | - Oliver P Ernst
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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65
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Kwon SK, Jun SH, Kim JF. Omega Rhodopsins: A Versatile Class of Microbial Rhodopsins. J Microbiol Biotechnol 2020; 30:633-641. [PMID: 32482928 PMCID: PMC9728251 DOI: 10.4014/jmb.1912.12010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/27/2020] [Indexed: 12/15/2022]
Abstract
Microbial rhodopsins are a superfamily of photoactive membrane proteins with covalently bound retinal cofactor. Isomerization of the retinal chromophore upon absorption of a photon triggers conformational changes of the protein to function as ion pumps or sensors. After the discovery of proteorhodopsin in an uncultivated γ-proteobacterium, light-activated proton pumps have been widely detected among marine bacteria and, together with chlorophyll-based photosynthesis, are considered as an important axis responsible for primary production in the biosphere. Rhodopsins and related proteins show a high level of phylogenetic diversity; we focus on a specific class of bacterial rhodopsins containing the 3 omega motif. This motif forms a stack of three nonconsecutive aromatic amino acids that correlates with the B-C loop orientation, and is shared among the phylogenetically close ion pumps such as the NDQ motif-containing sodium-pumping rhodopsin, the NTQ motif-containing chloride-pumping rhodopsin, and some proton-pumping rhodopsins including xanthorhodopsin. Here, we reviewed the recent research progress on these omega rhodopsins, and speculated on their evolutionary origin of functional diversity..
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Affiliation(s)
- Soon-Kyeong Kwon
- Division of Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Sung-Hoon Jun
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju 8119, Republic of Korea
| | - Jihyun F. Kim
- Department of Systems Biology, Division of Life Sciences, and Institute for Life Science and Biotechnology, Yonsei University, Seoul 0722, Republic of Korea
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66
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Koedooder C, Van Geersdaële R, Guéneuguès A, Bouget FY, Obernosterer I, Blain S. The interplay between iron limitation, light and carbon in the proteorhodopsin-containing Photobacterium angustum S14. FEMS Microbiol Ecol 2020; 96:5847691. [DOI: 10.1093/femsec/fiaa103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 05/25/2020] [Indexed: 01/01/2023] Open
Abstract
ABSTRACTIron (Fe) limitation is known to affect heterotrophic bacteria within the respiratory electron transport chain, therefore strongly impacting the overall intracellular energy production. We investigated whether the gene expression pattern of the light-sensitive proton pump, proteorhodopsin (PR), is influenced by varying light, carbon and Fe concentrations in the marine bacterium Photobacterium angustum S14 and whether PR can alleviate the physiological processes associated with Fe starvation. Our results show that the gene expression of PR increases as cells enter the stationary phase, irrespective of Fe-replete or Fe-limiting conditions. This upregulation is coupled to a reduction in cell size, indicating that PR gene regulation is associated with a specific starvation-stress response. We provide experimental evidence that PR gene expression does not result in an increased growth rate, cell abundance, enhanced survival or ATP concentration within the cell in either Fe-replete or Fe-limiting conditions. However, independent of PR gene expression, the presence of light did influence bacterial growth rates and maximum cell abundances under varying Fe regimes. Our observations support previous results indicating that PR phototrophy seems to play an important role within the stationary phase for several members of the Vibrionaceae family, but that the exact role of PR in Fe limitation remains to be further explored.
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Affiliation(s)
- Coco Koedooder
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, France
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rémy Van Geersdaële
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, France
| | - Audrey Guéneuguès
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, France
| | - François-Yves Bouget
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, France
| | - Ingrid Obernosterer
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, France
| | - Stéphane Blain
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, France
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Harris A, Lazaratos M, Siemers M, Watt E, Hoang A, Tomida S, Schubert L, Saita M, Heberle J, Furutani Y, Kandori H, Bondar AN, Brown LS. Mechanism of Inward Proton Transport in an Antarctic Microbial Rhodopsin. J Phys Chem B 2020; 124:4851-4872. [DOI: 10.1021/acs.jpcb.0c02767] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Andrew Harris
- Department of Physics, University of Guelph, 50 Stone Rd. E., Guelph, Ontario N1G 2W1, Canada
| | - Michalis Lazaratos
- Theoretical Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Malte Siemers
- Theoretical Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Ethan Watt
- Department of Physics, University of Guelph, 50 Stone Rd. E., Guelph, Ontario N1G 2W1, Canada
| | - Anh Hoang
- Department of Physics, University of Guelph, 50 Stone Rd. E., Guelph, Ontario N1G 2W1, Canada
| | - Sahoko Tomida
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Luiz Schubert
- Experimental Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Mattia Saita
- Experimental Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Joachim Heberle
- Experimental Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Yuji Furutani
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Ana-Nicoleta Bondar
- Theoretical Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Leonid S. Brown
- Department of Physics, University of Guelph, 50 Stone Rd. E., Guelph, Ontario N1G 2W1, Canada
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68
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Xue CX, Zhang H, Lin HY, Sun Y, Luo D, Huang Y, Zhang XH, Luo H. Ancestral niche separation and evolutionary rate differentiation between sister marine flavobacteria lineages. Environ Microbiol 2020; 22:3234-3247. [PMID: 32390223 DOI: 10.1111/1462-2920.15065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/05/2020] [Accepted: 05/07/2020] [Indexed: 12/30/2022]
Abstract
Marine flavobacteria are specialists for polysaccharide degradation. They dominate in habitats enriched with polysaccharides, but are also prevalent in pelagic environments where polysaccharides are less available. These niches are likely occupied by distinct lineages, but evolutionary processes underlying their niche differentiation remain elusive. Here, genomic analyses and physiological assays indicate that the sister flavobacteria lineages Leeuwenhoekiella and Nonlabens likely explore polysaccharide-rich macroalgae and polysaccharide-poor pelagic niches respectively. Phylogenomic analyses inferred that the niche separation likely occurred anciently and coincided with increased sequence evolutionary rate in Nonlabens compared with Leeuwenhoekiella. Further analyses ruled out the known mechanisms likely driving evolutionary rate acceleration, including reduced selection efficiency, decreased generation time and increased mutation rate. In particular, the mutation rates were determined using an unbiased experimental method, which measures the present-day populations and may not reflect ancestral populations. These data collectively lead to a new hypothesis that an ancestral and transient mutation rate increase resulted in evolutionary rate increase in Nonlabens. This hypothesis was supported by inferring that gains and losses of genes involved in SOS response, a mechanism known to drive transiently increased mutation rate, coincided with evolutionary rate acceleration. Our analyses highlight the evolutionary mechanisms underlying niche differentiation of flavobacteria lineages.
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Affiliation(s)
- Chun-Xu Xue
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.,Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Hao Zhang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - He-Yu Lin
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Ying Sun
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Danli Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Yongjie Huang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Xiao-Hua Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China
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69
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Unexpected Abundance and Diversity of Phototrophs in Mats from Morphologically Variable Microbialites in Great Salt Lake, Utah. Appl Environ Microbiol 2020; 86:AEM.00165-20. [PMID: 32198176 DOI: 10.1128/aem.00165-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/15/2020] [Indexed: 11/20/2022] Open
Abstract
Microbial mat communities are associated with extensive (∼700 km2) and morphologically variable carbonate structures, termed microbialites, in the hypersaline Great Salt Lake (GSL), Utah. However, whether the composition of GSL mat communities covaries with microbialite morphology and lake environment is unknown. Moreover, the potential adaptations that allow the establishment of these extensive mat communities at high salinity (14% to 17% total salts) are poorly understood. To address these questions, microbial mats were sampled from seven locations in the south arm of GSL representing different lake environments and microbialite morphologies. Despite the morphological differences, microbialite-associated mats were taxonomically similar and were dominated by the cyanobacterium Euhalothece and several heterotrophic bacteria. Metagenomic sequencing of a representative mat revealed Euhalothece and subdominant Thiohalocapsa populations that harbor the Calvin cycle and nitrogenase, suggesting they supply fixed carbon and nitrogen to heterotrophic bacteria. Fifteen of the next sixteen most abundant taxa are inferred to be aerobic heterotrophs and, surprisingly, harbor reaction center, rhodopsin, and/or bacteriochlorophyll biosynthesis proteins, suggesting aerobic photoheterotrophic (APH) capabilities. Importantly, proteins involved in APH are enriched in the GSL community relative to that in microbialite mat communities from lower salinity environments. These findings indicate that the ability to integrate light into energy metabolism is a key adaptation allowing for robust mat development in the hypersaline GSL.IMPORTANCE The earliest evidence of life on Earth is from organosedimentary structures, termed microbialites, preserved in 3.481-billion-year-old (Ga) rocks. Phototrophic microbial mats form in association with an ∼700-km2 expanse of morphologically diverse microbialites in the hypersaline Great Salt Lake (GSL), Utah. Here, we show taxonomically similar microbial mat communities are associated with morphologically diverse microbialites across the lake. Metagenomic sequencing reveals an abundance and diversity of autotrophic and heterotrophic taxa capable of harvesting light energy to drive metabolism. The unexpected abundance of and diversity in the mechanisms of harvesting light energy observed in GSL mat populations likely function to minimize niche overlap among coinhabiting taxa, provide a mechanism(s) to increase energy yield and osmotic balance during salt stress, and enhance fitness. Together, these physiological benefits promote the formation of robust mats that, in turn, influence the formation of morphologically diverse microbialite structures that can be imprinted in the rock record.
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70
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Leung PM, Bay SK, Meier DV, Chiri E, Cowan DA, Gillor O, Woebken D, Greening C. Energetic Basis of Microbial Growth and Persistence in Desert Ecosystems. mSystems 2020; 5:e00495-19. [PMID: 32291352 PMCID: PMC7159902 DOI: 10.1128/msystems.00495-19] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial life is surprisingly abundant and diverse in global desert ecosystems. In these environments, microorganisms endure a multitude of physicochemical stresses, including low water potential, carbon and nitrogen starvation, and extreme temperatures. In this review, we summarize our current understanding of the energetic mechanisms and trophic dynamics that underpin microbial function in desert ecosystems. Accumulating evidence suggests that dormancy is a common strategy that facilitates microbial survival in response to water and carbon limitation. Whereas photoautotrophs are restricted to specific niches in extreme deserts, metabolically versatile heterotrophs persist even in the hyper-arid topsoils of the Atacama Desert and Antarctica. At least three distinct strategies appear to allow such microorganisms to conserve energy in these oligotrophic environments: degradation of organic energy reserves, rhodopsin- and bacteriochlorophyll-dependent light harvesting, and oxidation of the atmospheric trace gases hydrogen and carbon monoxide. In turn, these principles are relevant for understanding the composition, functionality, and resilience of desert ecosystems, as well as predicting responses to the growing problem of desertification.
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Affiliation(s)
- Pok Man Leung
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Sean K Bay
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Dimitri V Meier
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Eleonora Chiri
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, University of Pretoria, Hatfield, Pretoria, South Africa
| | - Osnat Gillor
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Sde Boker, Israel
| | - Dagmar Woebken
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
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71
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Bioluminescent backlighting illuminates the complex visual signals of a social squid in the deep sea. Proc Natl Acad Sci U S A 2020; 117:8524-8531. [PMID: 32205436 DOI: 10.1073/pnas.1920875117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Visual signals rapidly relay information, facilitating behaviors and ecological interactions that shape ecosystems. However, most known signaling systems can be restricted by low light levels-a pervasive condition in the deep ocean, the largest inhabitable space on the planet. Resident visually cued animals have therefore been hypothesized to have simple signals with limited information-carrying capacity. We used cameras mounted on remotely operated vehicles to study the behavior of the Humboldt squid, Dosidicus gigas, in its natural deep-sea habitat. We show that specific pigmentation patterns from its diverse repertoire are selectively displayed during foraging and in social scenarios, and we investigate how these behaviors may be used syntactically for communication. We additionally identify the probable mechanism by which D. gigas, and related squids, illuminate these patterns to create visual signals that can be readily perceived in the deep, dark ocean. Numerous small subcutaneous (s.c.) photophores (bioluminescent organs) embedded throughout the muscle tissue make the entire body glow, thereby backlighting the pigmentation patterns. Equipped with a mechanism by which complex information can be rapidly relayed through a visual pathway under low-light conditions, our data suggest that the visual signals displayed by D. gigas could share design features with advanced forms of animal communication. Visual signaling by deep-living cephalopods will likely be critical in understanding how, and how much, information can be shared in one of the planet's most challenging environments for visual communication.
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72
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Vectorial Proton Transport Mechanism of RxR, a Phylogenetically Distinct and Thermally Stable Microbial Rhodopsin. Sci Rep 2020; 10:282. [PMID: 31937866 PMCID: PMC6959264 DOI: 10.1038/s41598-019-57122-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/30/2019] [Indexed: 11/08/2022] Open
Abstract
Rubrobacter xylanophilus rhodopsin (RxR) is a phylogenetically distinct and thermally stable seven-transmembrane protein that functions as a light-driven proton (H+) pump with the chromophore retinal. To characterize its vectorial proton transport mechanism, mutational and theoretical investigations were performed for carboxylates in the transmembrane region of RxR and the sequential proton transport steps were revealed as follows: (i) a proton of the retinylidene Schiff base (Lys209) is transferred to the counterion Asp74 upon formation of the blue-shifted M-intermediate in collaboration with Asp205, and simultaneously, a respective proton is released from the proton releasing group (Glu187/Glu197) to the extracellular side, (ii) a proton of Asp85 is transferred to the Schiff base during M-decay, (iii) a proton is taken up from the intracellular side to Asp85 during decay of the red-shifted O-intermediate. This ion transport mechanism of RxR provides valuable information to understand other ion transporters since carboxylates are generally essential for their functions.
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73
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Pachiadaki MG, Brown JM, Brown J, Bezuidt O, Berube PM, Biller SJ, Poulton NJ, Burkart MD, La Clair JJ, Chisholm SW, Stepanauskas R. Charting the Complexity of the Marine Microbiome through Single-Cell Genomics. Cell 2019; 179:1623-1635.e11. [PMID: 31835036 PMCID: PMC6919566 DOI: 10.1016/j.cell.2019.11.017] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/30/2019] [Accepted: 11/13/2019] [Indexed: 12/18/2022]
Abstract
Marine bacteria and archaea play key roles in global biogeochemistry. To improve our understanding of this complex microbiome, we employed single-cell genomics and a randomized, hypothesis-agnostic cell selection strategy to recover 12,715 partial genomes from the tropical and subtropical euphotic ocean. A substantial fraction of known prokaryoplankton coding potential was recovered from a single, 0.4 mL ocean sample, which indicates that genomic information disperses effectively across the globe. Yet, we found each genome to be unique, implying limited clonality within prokaryoplankton populations. Light harvesting and secondary metabolite biosynthetic pathways were numerous across lineages, highlighting the value of single-cell genomics to advance the identification of ecological roles and biotechnology potential of uncultured microbial groups. This genome collection enabled functional annotation and genus-level taxonomic assignments for >80% of individual metagenome reads from the tropical and subtropical surface ocean, thus offering a model to improve reference genome databases for complex microbiomes.
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Affiliation(s)
- Maria G Pachiadaki
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA; Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Julia M Brown
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Joseph Brown
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Oliver Bezuidt
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Paul M Berube
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Steven J Biller
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Nicole J Poulton
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
| | - James J La Clair
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
| | - Sallie W Chisholm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
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Salcher MM, Schaefle D, Kaspar M, Neuenschwander SM, Ghai R. Evolution in action: habitat transition from sediment to the pelagial leads to genome streamlining in Methylophilaceae. THE ISME JOURNAL 2019; 13:2764-2777. [PMID: 31292537 PMCID: PMC6794327 DOI: 10.1038/s41396-019-0471-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/14/2019] [Accepted: 06/21/2019] [Indexed: 12/15/2022]
Abstract
The most abundant aquatic microbes are small in cell and genome size. Genome-streamlining theory predicts gene loss caused by evolutionary selection driven by environmental factors, favouring superior competitors for limiting resources. However, evolutionary histories of such abundant, genome-streamlined microbes remain largely unknown. Here we reconstruct the series of steps in the evolution of some of the most abundant genome-streamlined microbes in freshwaters ("Ca. Methylopumilus") and oceans (marine lineage OM43). A broad genomic spectrum is visible in the family Methylophilaceae (Betaproteobacteria), from sediment microbes with medium-sized genomes (2-3 Mbp genome size), an occasionally blooming pelagic intermediate (1.7 Mbp), and the most reduced pelagic forms (1.3 Mbp). We show that a habitat transition from freshwater sediment to the relatively oligotrophic pelagial was accompanied by progressive gene loss and adaptive gains. Gene loss has mainly affected functions not necessarily required or advantageous in the pelagial or is encoded by redundant pathways. Likewise, we identified genes providing adaptations to oligotrophic conditions that have been transmitted horizontally from pelagic freshwater microbes. Remarkably, the secondary transition from the pelagial of lakes to the oceans required only slight modifications, i.e., adaptations to higher salinity, gained via horizontal gene transfer from indigenous microbes. Our study provides first genomic evidence of genome reduction taking place during habitat transitions. In this regard, the family Methylophilaceae is an exceptional model for tracing the evolutionary history of genome streamlining as such a collection of evolutionarily related microbes from different habitats is rare in the microbial world.
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Affiliation(s)
- Michaela M Salcher
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 7, 37005, České Budějovice, Czech Republic.
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Seestrasse 187, 8802, Kilchberg, Switzerland.
| | - Daniel Schaefle
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Seestrasse 187, 8802, Kilchberg, Switzerland
- Institute of Medical Microbiology, University of Zurich, Gloriastrasse 28/30, 8006, Zurich, Switzerland
| | - Melissa Kaspar
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Seestrasse 187, 8802, Kilchberg, Switzerland
| | - Stefan M Neuenschwander
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Seestrasse 187, 8802, Kilchberg, Switzerland
- Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001, Bern, Switzerland
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 7, 37005, České Budějovice, Czech Republic
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75
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76
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A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators. Proc Natl Acad Sci U S A 2019; 116:20574-20583. [PMID: 31548428 PMCID: PMC6789865 DOI: 10.1073/pnas.1907517116] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Giant viruses are remarkable for their large genomes, often rivaling those of small bacteria, and for having genes thought exclusive to cellular life. Most isolated to date infect nonmarine protists, leaving their strategies and prevalence in marine environments largely unknown. Using eukaryotic single-cell metagenomics in the Pacific, we discovered a Mimiviridae lineage of giant viruses, which infects choanoflagellates, widespread protistan predators related to metazoans. The ChoanoVirus genomes are the largest yet from pelagic ecosystems, with 442 of 862 predicted proteins lacking known homologs. They are enriched in enzymes for modifying organic compounds, including degradation of chitin, an abundant polysaccharide in oceans, and they encode 3 divergent type-1 rhodopsins (VirR) with distinct evolutionary histories from those that capture sunlight in cellular organisms. One (VirRDTS) is similar to the only other putative rhodopsin from a virus (PgV) with a known host (a marine alga). Unlike the algal virus, ChoanoViruses encode the entire pigment biosynthesis pathway and cleavage enzyme for producing the required chromophore, retinal. We demonstrate that the rhodopsin shared by ChoanoViruses and PgV binds retinal and pumps protons. Moreover, our 1.65-Å resolved VirRDTS crystal structure and mutational analyses exposed differences from previously characterized type-1 rhodopsins, all of which come from cellular organisms. Multiple VirR types are present in metagenomes from across surface oceans, where they are correlated with and nearly as abundant as a canonical marker gene from Mimiviridae Our findings indicate that light-dependent energy transfer systems are likely common components of giant viruses of photosynthetic and phagotrophic unicellular marine eukaryotes.
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77
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Gómez-Consarnau L, Raven JA, Levine NM, Cutter LS, Wang D, Seegers B, Arístegui J, Fuhrman JA, Gasol JM, Sañudo-Wilhelmy SA. Microbial rhodopsins are major contributors to the solar energy captured in the sea. SCIENCE ADVANCES 2019; 5:eaaw8855. [PMID: 31457093 PMCID: PMC6685716 DOI: 10.1126/sciadv.aaw8855] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 06/28/2019] [Indexed: 05/19/2023]
Abstract
All known phototrophic metabolisms on Earth rely on one of three categories of energy-converting pigments: chlorophyll-a (rarely -d), bacteriochlorophyll-a (rarely -b), and retinal, which is the chromophore in rhodopsins. While the significance of chlorophylls in solar energy capture has been studied for decades, the contribution of retinal-based phototrophy to this process remains largely unexplored. We report the first vertical distributions of the three energy-converting pigments measured along a contrasting nutrient gradient through the Mediterranean Sea and the Atlantic Ocean. The highest rhodopsin concentrations were observed above the deep chlorophyll-a maxima, and their geographical distribution tended to be inversely related to that of chlorophyll-a. We further show that proton-pumping proteorhodopsins potentially absorb as much light energy as chlorophyll-a-based phototrophy and that this energy is sufficient to sustain bacterial basal metabolism. This suggests that proteorhodopsins are a major energy-transducing mechanism to harvest solar energy in the surface ocean.
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Affiliation(s)
- Laura Gómez-Consarnau
- Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), 22860 Ensenada, Baja California, México
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - John A. Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
- School of Biological Sciences, University of Western Australia, 25 Stirling Highway, Crawley, WA 6009, Australia
| | - Naomi M. Levine
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Lynda S. Cutter
- Department of Earth Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Deli Wang
- State Key Laboratory of Marine Environmental Science, Xiamen University, 422 Siming Nanlu, 361005 Xiamen, China
| | - Brian Seegers
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Javier Arístegui
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Spain
| | - Jed A. Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Josep M. Gasol
- Institut de Ciències del Mar-CSIC, ES-08003 Barcelona, Catalonia, Spain
- Centre for Marine Ecosystems Research, School of Science, Edith Cowan University, Joondalup, WA, Australia
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78
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Taubert M, Grob C, Crombie A, Howat AM, Burns OJ, Weber M, Lott C, Kaster AK, Vollmers J, Jehmlich N, von Bergen M, Chen Y, Murrell JC. Communal metabolism by Methylococcaceae and Methylophilaceae is driving rapid aerobic methane oxidation in sediments of a shallow seep near Elba, Italy. Environ Microbiol 2019; 21:3780-3795. [PMID: 31267680 DOI: 10.1111/1462-2920.14728] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/14/2019] [Accepted: 06/29/2019] [Indexed: 11/29/2022]
Abstract
The release of abiotic methane from marine seeps into the atmosphere is a major source of this potent greenhouse gas. Methanotrophic microorganisms in methane seeps use methane as carbon and energy source, thus significantly mitigating global methane emissions. Here, we investigated microbial methane oxidation at the sediment-water interface of a shallow marine methane seep. Metagenomics and metaproteomics, combined with 13 C-methane stable isotope probing, demonstrated that various members of the gammaproteobacterial family Methylococcaceae were the key players for methane oxidation, catalysing the first reaction step to methanol. We observed a transfer of carbon to methanol-oxidizing methylotrophs of the betaproteobacterial family Methylophilaceae, suggesting an interaction between methanotrophic and methylotrophic microorganisms that allowed for rapid methane oxidation. From our microcosms, we estimated methane oxidation rates of up to 871 nmol of methane per gram sediment per day. This implies that more than 50% of methane at the seep is removed by microbial oxidation at the sediment-water interface, based on previously reported in situ methane fluxes. The organic carbon produced was further assimilated by different heterotrophic microbes, demonstrating that the methane-oxidizing community supported a complex trophic network. Our results provide valuable eco-physiological insights into this specialized microbial community performing an ecosystem function of global relevance.
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Affiliation(s)
- Martin Taubert
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Dornburger Str. 159 07743, Jena, Germany.,School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Carolina Grob
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Andrew Crombie
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Alexandra M Howat
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Oliver J Burns
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Miriam Weber
- HYDRA Marine Sciences GmbH, Sinzheim, Germany.,HYDRA Field Station Elba, Italy.,Microsensor Group, Max Plank Institute for Marine Microbiology, 28359, Celsiusstr. 1, Bremen, Germany
| | - Christian Lott
- HYDRA Marine Sciences GmbH, Sinzheim, Germany.,HYDRA Field Station Elba, Italy.,Department of Symbiosis, Max Plank Institute for Marine Microbiology, 28359, Celsiusstr. 1, Bremen, Germany
| | - Anne-Kristin Kaster
- Institute for Biological Interfaces (IBG5), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Karlsruhe, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, 38124, Inhoffenstrasse 7B, Braunschweig, Germany
| | - John Vollmers
- Institute for Biological Interfaces (IBG5), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Karlsruhe, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, 38124, Inhoffenstrasse 7B, Braunschweig, Germany
| | - Nico Jehmlich
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Martin von Bergen
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, 04103, Brüderstraße 32, Leipzig, Germany.,Department of Chemistry and Bioscience, University of Aalborg, 9220, Fredrik Bajers Vej 7H, Aalborg East, Denmark
| | - Yin Chen
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - John Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
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79
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Oppermann J, Fischer P, Silapetere A, Liepe B, Rodriguez-Rozada S, Flores-Uribe J, Schiewer E, Keidel A, Vierock J, Kaufmann J, Broser M, Luck M, Bartl F, Hildebrandt P, Wiegert JS, Béjà O, Hegemann P, Wietek J. MerMAIDs: a family of metagenomically discovered marine anion-conducting and intensely desensitizing channelrhodopsins. Nat Commun 2019; 10:3315. [PMID: 31346176 PMCID: PMC6658528 DOI: 10.1038/s41467-019-11322-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/24/2019] [Indexed: 01/07/2023] Open
Abstract
Channelrhodopsins (ChRs) are algal light-gated ion channels widely used as optogenetic tools for manipulating neuronal activity. ChRs desensitize under continuous bright-light illumination, resulting in a significant decline of photocurrents. Here we describe a metagenomically identified family of phylogenetically distinct anion-conducting ChRs (designated MerMAIDs). MerMAIDs almost completely desensitize during continuous illumination due to accumulation of a late non-conducting photointermediate that disrupts the ion permeation pathway. MerMAID desensitization can be fully explained by a single photocycle in which a long-lived desensitized state follows the short-lived conducting state. A conserved cysteine is the critical factor in desensitization, as its mutation results in recovery of large stationary photocurrents. The rapid desensitization of MerMAIDs enables their use as optogenetic silencers for transient suppression of individual action potentials without affecting subsequent spiking during continuous illumination. Our results could facilitate the development of optogenetic tools from metagenomic databases and enhance general understanding of ChR function.
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Affiliation(s)
- Johannes Oppermann
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Paul Fischer
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Arita Silapetere
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Bernhard Liepe
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Silvia Rodriguez-Rozada
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, Falkenried 94, 20251, Hamburg, Germany
| | - José Flores-Uribe
- Technion-Israel Institute of Technology, 32000, Haifa, Israel
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Enrico Schiewer
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Anke Keidel
- Institute for Chemistry, Physical Chemistry/Biophysical Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Johannes Vierock
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Joel Kaufmann
- Institute for Biology, Biophysical Chemistry, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Matthias Broser
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Meike Luck
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Franz Bartl
- Institute for Biology, Biophysical Chemistry, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany
| | - Peter Hildebrandt
- Institute for Chemistry, Physical Chemistry/Biophysical Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - J Simon Wiegert
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, Falkenried 94, 20251, Hamburg, Germany
| | - Oded Béjà
- Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany.
| | - Jonas Wietek
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115, Berlin, Germany.
- Department of Neurobiology, Weizmann Institute of Science, 7610001, Rehovot, Israel.
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80
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Pereira O, Hochart C, Auguet JC, Debroas D, Galand PE. Genomic ecology of Marine Group II, the most common marine planktonic Archaea across the surface ocean. Microbiologyopen 2019; 8:e00852. [PMID: 31264806 PMCID: PMC6741140 DOI: 10.1002/mbo3.852] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/08/2019] [Accepted: 04/08/2019] [Indexed: 01/22/2023] Open
Abstract
Planktonic Archaea have been detected in all the world's oceans and are found from surface waters to the deep sea. The two most common Archaea phyla are Thaumarchaeota and Euryarchaeota. Euryarchaeota are generally more common in surface waters, but very little is known about their ecology and their potential metabolisms. In this study, we explore the genomic ecology of the Marine Group II (MGII), the main marine planktonic Euryarchaeota, and test if it is composed of different ecologically relevant units. We re‐analyzed Tara Oceans metagenomes from the photic layer and the deep ocean by annotating sequences against a custom MGII database and by mapping gene co‐occurrences. Our data provide a global view of the distribution of Euryarchaeota, and more specifically of MGII subgroups, and reveal their association to a number of gene‐coding sequences. In particular, we show that MGII proteorhodopsins were detected in both the surface and the deep chlorophyll maximum layer and that different clusters of these light harvesting proteins were present. Our approach helped describing the set of genes found together with specific MGII subgroups. We could thus define genomic environments that could theoretically describe ecologically meaningful units and the ecological niche that they occupy.
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Affiliation(s)
- Olivier Pereira
- Sorbonne Université, CNRS, Laboratoire d'Ecogéochimie des Environnements Benthiques (LECOB), Observatoire Océanologique de Banyuls, Banyuls sur Mer, France
| | - Corentin Hochart
- Laboratoire Microorganismes: Génome et Environnement, UMR 6023, CNRS - Université Blaise Pascal, Aubière, France
| | - Jean Christophe Auguet
- Marine Biodiversity, Exploitation and Conservation (MARBEC), Université de Montpellier, CNRS, IFREMER, Montpellier, France
| | - Didier Debroas
- Laboratoire Microorganismes: Génome et Environnement, UMR 6023, CNRS - Université Blaise Pascal, Aubière, France
| | - Pierre E Galand
- Sorbonne Université, CNRS, Laboratoire d'Ecogéochimie des Environnements Benthiques (LECOB), Observatoire Océanologique de Banyuls, Banyuls sur Mer, France
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81
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Gómez-Consarnau L, Needham DM, Weber PK, Fuhrman JA, Mayali X. Influence of Light on Particulate Organic Matter Utilization by Attached and Free-Living Marine Bacteria. Front Microbiol 2019; 10:1204. [PMID: 31214143 PMCID: PMC6558058 DOI: 10.3389/fmicb.2019.01204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/13/2019] [Indexed: 11/13/2022] Open
Abstract
Light plays a central role on primary productivity of aquatic systems. Yet, its potential impact on the degradation of photosynthetically produced biomass is not well understood. We investigated the patterns of light-induced particle breakdown and bacterial assimilation of detrital C and N using 13C and 15N labeled freeze-thawed diatom cells incubated in laboratory microcosms with a marine microbial community freshly collected from the Pacific Ocean. Particles incubated in the dark resulted in increased bacterial counts and dissolved organic carbon concentrations compared to those incubated in the light. Light also influenced the attached and free-living microbial community structure as detected by 16S rRNA gene amplicon sequencing. For example, Sphingobacteriia were enriched on dark-incubated particles and taxa from the family Flavobacteriaceae and the genus Pseudoalteromonas were numerically enriched on particles in the light. Isotope incorporation analysis by phylogenetic microarray and NanoSIMS (a method called Chip-SIP) identified free-living and attached microbial taxa able to incorporate N and C from the particles. Some taxa, including members of the Flavobacteriaceae and Cryomorphaceae, exhibited increased isotope incorporation in the light, suggesting the use of photoheterotrophic metabolisms. In contrast, some members of Oceanospirillales and Rhodospirillales showed decreased isotope incorporation in the light, suggesting that their heterotrophic metabolism, particularly when occurring on particles, might increase at night or may be inhibited by sunlight. These results show that light influences particle degradation and C and N incorporation by attached bacteria, suggesting that the transfer between particulate and free-living phases are likely affected by external factors that change with the light regime, such as time of day, water column depth and season.
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Affiliation(s)
- Laura Gómez-Consarnau
- Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Mexico.,Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - David M Needham
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Peter K Weber
- Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Xavier Mayali
- Lawrence Livermore National Laboratory, Livermore, CA, United States
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82
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Flores-Uribe J, Hevroni G, Ghai R, Pushkarev A, Inoue K, Kandori H, Béjà O. Heliorhodopsins are absent in diderm (Gram-negative) bacteria: Some thoughts and possible implications for activity. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:419-424. [PMID: 30618066 DOI: 10.1111/1758-2229.12730] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/27/2018] [Accepted: 12/27/2018] [Indexed: 06/09/2023]
Abstract
Microbial heliorhodopsins are a new type of rhodopsins, currently believed to engage in light sensing, with an opposite membrane topology compared to type-1 and type-2 rhodopsins. We determined heliorhodopsins presence/absence is monoderms and diderms representatives from the Tara Oceans and freshwater metagenomes as well as metagenome assembled genome collections. Heliorhodopsins are absent in diderms, confirming our previous observations in cultured Proteobacteria. We do not rule out the possibility that heliorhodopsins serve as light sensors. However, this does not easily explain their absence from diderms. Based on these observations, we speculate on the putative role of heliorhodopsins in light-driven transport of amphiphilic molecules.
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Affiliation(s)
- José Flores-Uribe
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Gur Hevroni
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Rohit Ghai
- Institute of Hydrobiology, Department of Aquatic Microbial Ecology, Biology Center of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Alina Pushkarev
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Keiichi Inoue
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Aichi, 466-8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Aichi, 466-8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Oded Béjà
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
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83
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Terashima M, Ohashi K, Takasuka TE, Kojima H, Fukui M. Antarctic heterotrophic bacterium Hymenobacter nivis P3 T displays light-enhanced growth and expresses putative photoactive proteins. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:227-235. [PMID: 30298689 DOI: 10.1111/1758-2229.12702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 10/02/2018] [Indexed: 06/08/2023]
Abstract
Hymenobacter nivis P3T is a heterotrophic bacterium isolated from Antarctic red snow generated by algal blooms. Despite being non-photosynthetic, H. nivis was dominantly found in the red snow environment that is exposed to high light and UV irradiation, suggesting that this species can flourish under such harsh conditions. In order to further understand the adaptive strategies on the snow surface environment of Antarctica, the genome of H. nivis P3T was sequenced and analyzed, which identified genes putatively encoding for light-reactive proteins such as proteorhodopsin, phytochrome, photolyase and several copies of cryptochromes. Culture-based experiments revealed that H. nivis P3T growth was significantly enhanced under light conditions, while dark conditions had increased extracellular polymeric substances. Furthermore, the expression of several putative light-reactive proteins was determined by proteomic analysis. These results indicate that H. nivis P3T is able to potentially utilize light, which may explain its dominance on the red snow surface environment of Antarctica. ORIGINALITY-SIGNIFICANCE STATEMENT: The role of proteorhodopsin in heterotrophic bacteria is not well-characterized, as only a handful of proteorhodopsin-harbouring isolates were shown to have a light-enhanced phenotype through culture-based experiments to date. This is the first study that demonstrates light-stimulated growth and protein expression evidence of photoactive proteins for a non-marine psychrophile and for a member of the genus Hymenobacter. It is also the first study that provides comprehensive proteome information for this genus. This study presents significant results in understanding the adaptive mechanism of a heterotrophic non-photosynthetic bacterium thriving on the snow surface environment of Antarctica as well as demonstrating the role of light-utilization in promoting growth, possibly through proteorhodopsin.
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Affiliation(s)
- Mia Terashima
- Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo, 060-0819, Japan
| | - Keisuke Ohashi
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589, Japan
| | - Taichi E Takasuka
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589, Japan
| | - Hisaya Kojima
- Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo, 060-0819, Japan
| | - Manabu Fukui
- Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo, 060-0819, Japan
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84
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Idso MN, Baxter NR, Narayanan S, Chang E, Fisher J, Chmelka BF, Han S. Proteorhodopsin Function Is Primarily Mediated by Oligomerization in Different Micellar Surfactant Solutions. J Phys Chem B 2019; 123:4180-4192. [DOI: 10.1021/acs.jpcb.9b00922] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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85
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Rinke C, Rubino F, Messer LF, Youssef N, Parks DH, Chuvochina M, Brown M, Jeffries T, Tyson GW, Seymour JR, Hugenholtz P. A phylogenomic and ecological analysis of the globally abundant Marine Group II archaea (Ca. Poseidoniales ord. nov.). THE ISME JOURNAL 2019; 13:663-675. [PMID: 30323263 PMCID: PMC6461757 DOI: 10.1038/s41396-018-0282-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 08/24/2018] [Accepted: 09/01/2018] [Indexed: 01/08/2023]
Abstract
Marine Group II (MGII) archaea represent the most abundant planktonic archaeal group in ocean surface waters, but our understanding of the group has been limited by a lack of cultured representatives and few sequenced genomes. Here, we conducted a comparative phylogenomic analysis of 270 recently available MGII metagenome-assembled genomes (MAGs) to investigate their evolution and ecology. Based on a rank-normalised genome phylogeny, we propose that MGII is an order-level lineage for which we propose the name Candidatus Poseidoniales (after Gr. n. Poseidon, God of the sea), comprising the families Candidatus Poseidonaceae fam. nov. (formerly subgroup MGIIa) and Candidatus Thalassarchaeaceae fam. nov. (formerly subgroup MGIIb). Within these families, 21 genera could be resolved, many of which had distinct biogeographic ranges and inferred nutrient preferences. Phylogenetic analyses of key metabolic functions suggest that the ancestor of Ca. Poseidoniales was a surface water-dwelling photoheterotroph that evolved to occupy multiple related ecological niches based primarily on spectral tuning of proteorhodopsin genes. Interestingly, this adaptation appears to involve an overwrite mechanism whereby an existing single copy of the proteorhodopsin gene is replaced by a horizontally transferred copy, which in many instances should allow an abrupt change in light absorption capacity. Phototrophy was lost entirely from five Ca. Poseidoniales genera coinciding with their adaptation to deeper aphotic waters. We also report the first instances of nitrate reductase in two genera acquired via horizontal gene transfer (HGT), which was a potential adaptation to oxygen limitation. Additional metabolic traits differentiating families and genera include flagellar-based adhesion, transporters, and sugar, amino acid, and peptide degradation. Our results suggest that HGT has shaped the evolution of Ca. Poseidoniales to occupy a variety of ecological niches and to become the most successful archaeal lineage in ocean surface waters.
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Affiliation(s)
- Christian Rinke
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia.
| | - Francesco Rubino
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Lauren F Messer
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Noha Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University Stillwater, Stillwater, OK, USA
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Maria Chuvochina
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Mark Brown
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Thomas Jeffries
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, NSW, Australia
| | - Gene W Tyson
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Justin R Seymour
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia
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86
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Fernández-Gómez B, Díez B, Polz MF, Arroyo JI, Alfaro FD, Marchandon G, Sanhueza C, Farías L, Trefault N, Marquet PA, Molina-Montenegro MA, Sylvander P, Snoeijs-Leijonmalm P. Bacterial community structure in a sympagic habitat expanding with global warming: brackish ice brine at 85-90 °N. THE ISME JOURNAL 2019; 13:316-333. [PMID: 30228379 PMCID: PMC6331608 DOI: 10.1038/s41396-018-0268-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/11/2018] [Accepted: 07/24/2018] [Indexed: 01/13/2023]
Abstract
Larger volumes of sea ice have been thawing in the Central Arctic Ocean (CAO) during the last decades than during the past 800,000 years. Brackish brine (fed by meltwater inside the ice) is an expanding sympagic habitat in summer all over the CAO. We report for the first time the structure of bacterial communities in this brine. They are composed of psychrophilic extremophiles, many of them related to phylotypes known from Arctic and Antarctic regions. Community structure displayed strong habitat segregation between brackish ice brine (IB; salinity 2.4-9.6) and immediate sub-ice seawater (SW; salinity 33.3-34.9), expressed at all taxonomic levels (class to genus), by dominant phylotypes as well as by the rare biosphere, and with specialists dominating IB and generalists SW. The dominant phylotypes in IB were related to Candidatus Aquiluna and Flavobacterium, those in SW to Balneatrix and ZD0405, and those shared between the habitats to Halomonas, Polaribacter and Shewanella. A meta-analysis for the oligotrophic CAO showed a pattern with Flavobacteriia dominating in melt ponds, Flavobacteriia and Gammaproteobacteria in solid ice cores, Flavobacteriia, Gamma- and Betaproteobacteria, and Actinobacteria in brine, and Alphaproteobacteria in SW. Based on our results, we expect that the roles of Actinobacteria and Betaproteobacteria in the CAO will increase with global warming owing to the increased production of meltwater in summer. IB contained three times more phylotypes than SW and may act as an insurance reservoir for bacterial diversity that can act as a recruitment base when environmental conditions change.
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Affiliation(s)
- Beatriz Fernández-Gómez
- Department of Molecular Genetics and Microbiology, Pontifical University Catholic of Chile, Santiago, Chile
- INTA-Universidad de Chile, Santiago, Chile
| | - Beatriz Díez
- Department of Molecular Genetics and Microbiology, Pontifical University Catholic of Chile, Santiago, Chile.
- Center for Climate and Resilience Research, Concepción, Chile.
| | - Martin F Polz
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | - José Ignacio Arroyo
- Department of Ecology, Pontifical University Catholic of Chile, Santiago, Chile
| | - Fernando D Alfaro
- GEMA Center for Genomics, Ecology & Environment, Universidad Mayor, Santiago, Chile
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Germán Marchandon
- Department of Molecular Genetics and Microbiology, Pontifical University Catholic of Chile, Santiago, Chile
| | - Cynthia Sanhueza
- Department of Molecular Genetics and Microbiology, Pontifical University Catholic of Chile, Santiago, Chile
| | - Laura Farías
- Center for Climate and Resilience Research, Concepción, Chile
- Department of Oceanography, Universidad de Concepción, Concepción, Chile
| | - Nicole Trefault
- GEMA Center for Genomics, Ecology & Environment, Universidad Mayor, Santiago, Chile
| | - Pablo A Marquet
- Department of Ecology, Pontifical University Catholic of Chile, Santiago, Chile
- Instituto de Ecología y Biodiversidad, Universidad de Chile, Santiago, Chile
| | - Marco A Molina-Montenegro
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
- Centro de Estudios Avanzados en Zonas Áridas, Universidad Católica del Norte, Coquimbo, Chile
| | - Peter Sylvander
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
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87
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Tully BJ. Metabolic diversity within the globally abundant Marine Group II Euryarchaea offers insight into ecological patterns. Nat Commun 2019; 10:271. [PMID: 30655514 PMCID: PMC6336850 DOI: 10.1038/s41467-018-07840-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/03/2018] [Indexed: 11/08/2022] Open
Abstract
Despite their discovery over 25 years ago, the Marine Group II Euryarchaea (MGII) remain a difficult group of organisms to study, lacking cultured isolates and genome references. The MGII have been identified in marine samples from around the world, and evidence supports a photoheterotrophic lifestyle combining phototrophy via proteorhodopsins with the remineralization of high molecular weight organic matter. Divided between two clades, the MGII have distinct ecological patterns that are not understood based on the limited number of available genomes. Here, I present a comparative genomic analysis of 250 MGII genomes, providing a comprehensive investigation of these mesophilic archaea. This analysis identifies 17 distinct subclades including nine subclades that previously lacked reference genomes. The metabolic potential and distribution of the MGII genera reveals distinct roles in the environment, identifying algal-saccharide-degrading coastal subclades, protein-degrading oligotrophic surface ocean subclades, and mesopelagic subclades lacking proteorhodopsins, common in all other subclades.
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Affiliation(s)
- Benjamin J Tully
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
- Center for Dark Energy Biosphere Investigations, University of Southern California, Los Angeles, CA, 90089, USA.
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88
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Srinivasan K, Buys EM. Insights into the role of bacteria in vitamin A biosynthesis: Future research opportunities. Crit Rev Food Sci Nutr 2019; 59:3211-3226. [PMID: 30638045 DOI: 10.1080/10408398.2018.1546670] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Significant efforts have been made to address the hidden hunger challenges due to iron, zinc, iodine, and vitamin A since the beginning of the 21st century. Prioritizing the vitamin A deficiency (VAD) disorders, many countries are looking for viable alternative strategies such as biofortification. One of the leading causes of VAD is the poor bioconversion of β-carotene into retinoids. This review is focused on the opportunities of bacterial biosynthesis of retinoids, in particular, through the gut microbiota. The proposed hypothesis starts with the premise that an animal can able to store and timely convert carotenoids into retinoids in the liver and intestinal tissues. This theory is experimental with many scientific insights. The syntrophic metabolism, potential crosstalk of bile acids, lipocalins and lipopolysaccharides of gut microbiota are reported to contribute significantly to the retinoid biosynthesis. The gut bacteria respond to these kinds of factors by genetic restructuring driven mainly by events like horizontal gene transfer. A phylogenetic analysis of β-carotene 15, 15'-mono (di) oxygenase enzymes among a selected group of prokaryotes and eukaryotes was carried out to validate the hypotheses. Shedding light on the probiotic strategies through non-genetically modified organism such as gut bacteria capable of synthesizing vitamin A would address the VAD disorders.
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Affiliation(s)
- K Srinivasan
- Department of Consumer and Food Sciences, University of Pretoria, Hatfield Campus, Pretoria, South Africa
| | - Elna M Buys
- Department of Consumer and Food Sciences, University of Pretoria, Hatfield Campus, Pretoria, South Africa
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89
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Soto-Rodríguez J, Baneyx F. Role of the signal sequence in proteorhodopsin biogenesis in E. coli. Biotechnol Bioeng 2018; 116:912-918. [PMID: 30475397 DOI: 10.1002/bit.26878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/16/2018] [Accepted: 11/21/2018] [Indexed: 12/16/2022]
Abstract
Blue-absorbing proteorhodopsin (BPR) from marine bacteria is a retinal-bound, light-activated, outwards proton transporter containing seven α-helical transmembrane segments (TMS). It is synthesized as a precursor species (pre-BPR) with a predicted N-terminal signal sequence that is cleaved to yield the mature protein. While optimizing the production of BPR in Escherichia coli to facilitate the construction of bioprotonic devices, we observed significant pre-BPR accumulation in the inner membrane and explored signal sequence requirements and export pathway. We report here that BPR does not rely on the Sec pathway for inner membrane integration, and that although it greatly enhances yields, its signal sequence is not necessary to obtain a functional product. We further show that an unprocessable version of pre-BPR obtained by mutagenesis of the signal peptidase I site exhibits all functional attributes of the wild-type protein and has the advantage of being produced at higher levels. Our results are consistent with the BPR signal sequence being recognized by the signal recognition particle (SRP; a protein that orchestrates the cotranslational biogenesis of inner membrane proteins) and serving as a beneficial "pro" domain rather than a traditional secretory peptide.
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Affiliation(s)
| | - François Baneyx
- Department of Chemical Engineering, University of Washington, Seattle, Washington
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90
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Pohlschroder M, Pfeiffer F, Schulze S, Abdul Halim MF. Archaeal cell surface biogenesis. FEMS Microbiol Rev 2018; 42:694-717. [PMID: 29912330 PMCID: PMC6098224 DOI: 10.1093/femsre/fuy027] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/12/2018] [Indexed: 12/13/2022] Open
Abstract
Cell surfaces are critical for diverse functions across all domains of life, from cell-cell communication and nutrient uptake to cell stability and surface attachment. While certain aspects of the mechanisms supporting the biosynthesis of the archaeal cell surface are unique, likely due to important differences in cell surface compositions between domains, others are shared with bacteria or eukaryotes or both. Based on recent studies completed on a phylogenetically diverse array of archaea, from a wide variety of habitats, here we discuss advances in the characterization of mechanisms underpinning archaeal cell surface biogenesis. These include those facilitating co- and post-translational protein targeting to the cell surface, transport into and across the archaeal lipid membrane, and protein anchoring strategies. We also discuss, in some detail, the assembly of specific cell surface structures, such as the archaeal S-layer and the type IV pili. We will highlight the importance of post-translational protein modifications, such as lipid attachment and glycosylation, in the biosynthesis as well as the regulation of the functions of these cell surface structures and present the differences and similarities in the biogenesis of type IV pili across prokaryotic domains.
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Affiliation(s)
| | - Friedhelm Pfeiffer
- Computational Biology Group, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Stefan Schulze
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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91
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Vigneron A, Cruaud P, Mohit V, Martineau MJ, Culley AI, Lovejoy C, Vincent WF. Multiple Strategies for Light-Harvesting, Photoprotection, and Carbon Flow in High Latitude Microbial Mats. Front Microbiol 2018; 9:2881. [PMID: 30564204 PMCID: PMC6288179 DOI: 10.3389/fmicb.2018.02881] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/09/2018] [Indexed: 12/27/2022] Open
Abstract
Microbial mats are ubiquitous in polar freshwater ecosystems and sustain high concentrations of biomass despite the extreme seasonal variations in light and temperature. Here we aimed to resolve genomic adaptations for light-harvesting, bright-light protection, and carbon flow in mats that undergo seasonal freeze-up. To bracket a range of communities in shallow water habitats, we sampled cyanobacterial mats in the thawed littoral zone of two lakes situated at the northern and southern limits of the Canadian Arctic permafrost zone. We applied a multiphasic approach using pigment profiles from high performance liquid chromatography, Illumina MiSeq sequencing of the 16S and 18S rRNA genes, and metagenomic analysis. The mats shared a taxonomic and functional core microbiome, dominated by oxygenic cyanobacteria with light-harvesting and photoprotective pigments, bacteria with bacteriochlorophyll, and bacteria with light-driven Type I rhodopsins. Organisms able to use light for energy related processes represented up to 85% of the total microbial community, with 15–30% attributable to cyanobacteria and 55–70% attributable to other bacteria. The proportion of genes involved in anaplerotic CO2 fixation was greater than for genes associated with oxygenic photosynthesis. Diverse heterotrophic bacteria, eukaryotes (including metazoans and fungi) and viruses co-occurred in both communities. The results indicate a broad range of strategies for capturing sunlight and CO2, and for the subsequent flow of energy and carbon in these complex, light-driven microbial ecosystems.
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Affiliation(s)
- Adrien Vigneron
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Perrine Cruaud
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada.,Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Québec, QC, Canada
| | - Vani Mohit
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Marie-Josée Martineau
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada
| | - Alexander I Culley
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada.,Département de Biochimie, de Microbiologie et de Bio-informatique, Université Laval, Québec, QC, Canada
| | - Connie Lovejoy
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
| | - Warwick F Vincent
- Centre d'Études Nordiques, Takuvik Joint International Laboratory, Université Laval, Québec, QC, Canada.,Département de Biologie, Université Laval, Québec, QC, Canada.,Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
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92
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Sorokin DY, Muntyan MS, Toshchakov SV, Korzhenkov A, Kublanov IV. Phenotypic and Genomic Properties of a Novel Deep-Lineage Haloalkaliphilic Member of the Phylum Balneolaeota From Soda Lakes Possessing Na +-Translocating Proteorhodopsin. Front Microbiol 2018; 9:2672. [PMID: 30483225 PMCID: PMC6243061 DOI: 10.3389/fmicb.2018.02672] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/19/2018] [Indexed: 12/14/2022] Open
Abstract
Stable development of a heterotrophic bacterial satellite with a peculiar cell morphology has been observed in several enrichment cultures of haloalkaliphilic benthic filamentous cyanobacteria from a hypersaline soda lake in Kulunda Steppe (Altai, Russia). The organism was isolated in pure culture (strain Omega) using sonicated cyanobacterial cells as substrate and it was identified as a deep phylogenetic lineage within the recently proposed phylum Balneolaeota. It is an obligately aerobic heterotroph utilizing proteins and peptides for growth. The cell morphology significantly varied from semicircles to long filaments depending on the growth conditions. The cultures are red-orange colored due to a presence of carotenoids. The isolate is an obligate alkaliphile with a pH range for growth from 8.5 to 10.5 (optimum at 9.5-10) and moderately salt-tolerant with a range from 0.3 to 3 M total Na+ (optimum at 1 M). The genome analysis of strain Omega demonstrated a presence of gene, encoding a proteorhodopsin forming a separate branch in the sodium-translocating proteorhodopsin family. Experiments with washed cells of Omega confirmed light-dependent sodium export. A possible physiological role of the sodium proteorhodopsin in strain Omega is discussed. Phylogenomic analysis demostrated that strain Omega forms an deep, independent branch of a new genus and family level within a recently established phylum Balneolaeota.
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Affiliation(s)
- Dimitry Y. Sorokin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Maria S. Muntyan
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Stepan V. Toshchakov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | | | - Ilya V. Kublanov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
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93
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Sieradzki ET, Fuhrman JA, Rivero-Calle S, Gómez-Consarnau L. Proteorhodopsins dominate the expression of phototrophic mechanisms in seasonal and dynamic marine picoplankton communities. PeerJ 2018; 6:e5798. [PMID: 30370186 PMCID: PMC6202958 DOI: 10.7717/peerj.5798] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/20/2018] [Indexed: 12/13/2022] Open
Abstract
The most abundant and ubiquitous microbes in the surface ocean use light as an energy source, capturing it via complex chlorophyll-based photosystems or simple retinal-based rhodopsins. Studies in various ocean regimes compared the abundance of these mechanisms, but few investigated their expression. Here we present the first full seasonal study of abundance and expression of light-harvesting mechanisms (proteorhodopsin, PR; aerobic anoxygenic photosynthesis, AAnP; and oxygenic photosynthesis, PSI) from deep-sequenced metagenomes and metatranscriptomes of marine picoplankton (<1 µm) at three coastal stations of the San Pedro Channel in the Pacific Ocean. We show that, regardless of season or sampling location, the most common phototrophic mechanism in metagenomes of this dynamic region was PR (present in 65–104% of the genomes as estimated by single-copy recA), followed by PSI (5–104%) and AAnP (5–32%). Furthermore, the normalized expression (RNA to DNA ratio) of PR genes was higher than that of oxygenic photosynthesis (average ± standard deviation 26.2 ± 8.4 vs. 11 ± 9.7), and the expression of the AAnP marker gene was significantly lower than both mechanisms (0.013 ± 0.02). We demonstrate that PR expression was dominated by the SAR11-cluster year-round, followed by other Alphaproteobacteria, unknown-environmental clusters and Gammaproteobacteria. This highly dynamic system further allowed us to identify a trend for PR spectral tuning, in which blue-absorbing PR genes dominate in areas with low chlorophyll-a concentrations (<0.25 µgL−1). This suggests that PR phototrophy is not an accessory function but instead a central mechanism that can regulate photoheterotrophic population dynamics.
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Affiliation(s)
- Ella T Sieradzki
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States of America
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States of America
| | - Sara Rivero-Calle
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States of America
| | - Laura Gómez-Consarnau
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States of America
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94
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Haro-Moreno JM, López-Pérez M, de la Torre JR, Picazo A, Camacho A, Rodriguez-Valera F. Fine metagenomic profile of the Mediterranean stratified and mixed water columns revealed by assembly and recruitment. MICROBIOME 2018; 6:128. [PMID: 29991350 PMCID: PMC6040077 DOI: 10.1186/s40168-018-0513-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/02/2018] [Indexed: 05/07/2023]
Abstract
BACKGROUND The photic zone of aquatic habitats is subjected to strong physicochemical gradients. To analyze the fine-scale variations in the marine microbiome, we collected seven samples from a single offshore location in the Mediterranean at 15 m depth intervals during a period of strong stratification, as well as two more samples during the winter when the photic water column was mixed. We were able to recover 94 new metagenome-assembled genomes (MAGs) from these metagenomes and examine the distribution of key marine microbes within the photic zone using metagenomic recruitment. RESULTS Our results showed significant differences in the microbial composition of different layers within the stratified photic water column. The majority of microorganisms were confined to discreet horizontal layers of no more than 30 m (stenobathic). Only a few such as members of the SAR11 clade appeared at all depths (eurybathic). During the winter mixing period, only some groups of bloomers such as Pseudomonas were favored. Although most microbes appeared in both seasons, some groups like the SAR116 clade and some Bacteroidetes and Verrucomicrobia seemed to disappear during the mixing period. Furthermore, we found that some microbes previously considered seasonal (e.g., Archaea or Actinobacteria) were living in deeper layers within the photic zone during the stratification period. A strong depth-related specialization was detected, not only at the taxonomic level but also at the functional level, even within the different clades, for the manipulation and uptake of specific polysaccharides. Rhodopsin sequences (green or blue) also showed narrow depth distributions that correlated with the taxonomy of the microbe in which they were found but not with depth. CONCLUSIONS Although limited to a single location in the Mediterranean, this study has profound implications for our understanding of how marine microbial communities vary with depth within the photic zone when stratified. Our results highlight the importance of collecting samples at different depths in the water column when comparing seasonal variations and have important ramifications for global marine studies that most often take samples from only one single depth. Furthermore, our perspective and approaches (metagenomic assembly and recruitment) are broadly applicable to other metagenomic studies.
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Affiliation(s)
- Jose M Haro-Moreno
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, Apartado 18, San Juan de Alicante, 03550, Alicante, Spain
| | - Mario López-Pérez
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, Apartado 18, San Juan de Alicante, 03550, Alicante, Spain
| | - José R de la Torre
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, USA
| | - Antonio Picazo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Burjassot, E-46100, Valencia, Spain
| | - Antonio Camacho
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Burjassot, E-46100, Valencia, Spain
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, Apartado 18, San Juan de Alicante, 03550, Alicante, Spain.
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95
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Maresca JA, Miller KJ, Keffer JL, Sabanayagam CR, Campbell BJ. Distribution and Diversity of Rhodopsin-Producing Microbes in the Chesapeake Bay. Appl Environ Microbiol 2018; 84:e00137-18. [PMID: 29703736 PMCID: PMC6007120 DOI: 10.1128/aem.00137-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/23/2018] [Indexed: 01/09/2023] Open
Abstract
Although sunlight is an abundant source of energy in surface environments, less than 0.5% of the available photons are captured by (bacterio)chlorophyll-dependent photosynthesis in plants and bacteria. Metagenomic data indicate that 30 to 60% of the bacterial genomes in some environments encode rhodopsins, retinal-based photosystems found in heterotrophs, suggesting that sunlight may provide energy for more life than previously suspected. However, quantitative data on the number of cells that produce rhodopsins in environmental systems are limited. Here, we use total internal reflection fluorescence microscopy to show that the number of free-living microbes that produce rhodopsins increases along the salinity gradient in the Chesapeake Bay. We correlate this functional data with environmental data to show that rhodopsin abundance is positively correlated with salinity and with indicators of active heterotrophy during the day. Metagenomic and metatranscriptomic data suggest that the microbial rhodopsins in the low-salinity samples are primarily found in Actinobacteria and Bacteroidetes, while those in the high-salinity samples are associated with SAR-11 type AlphaproteobacteriaIMPORTANCE Microbial rhodopsins are common light-activated ion pumps in heterotrophs, and previous work has proposed that heterotrophic microbes use them to conserve energy when organic carbon is limiting. If this hypothesis is correct, rhodopsin-producing cells should be most abundant where nutrients are most limited. Our results indicate that in the Chesapeake Bay, rhodopsin gene abundance is correlated with salinity, and functional rhodopsin production is correlated with nitrate, bacterial production, and chlorophyll a We propose that in this environment, where carbon and nitrogen are likely not limiting, heterotrophs do not need to use rhodopsins to supplement ATP synthesis. Rather, the light-generated proton motive force in nutrient-rich environments could be used to power energy-dependent membrane-associated processes, such as active transport of organic carbon and cofactors, enabling these organisms to more efficiently utilize exudates from primary producers.
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Affiliation(s)
- Julia A Maresca
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | - Kelsey J Miller
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Jessica L Keffer
- Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA
| | | | - Barbara J Campbell
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
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96
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Thiel V, Tank M, Bryant DA. Diversity of Chlorophototrophic Bacteria Revealed in the Omics Era. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:21-49. [PMID: 29505738 DOI: 10.1146/annurev-arplant-042817-040500] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Because of recent advances in omics methodologies, knowledge of chlorophototrophy (i.e., chlorophyll-based phototrophy) in bacteria has rapidly increased. Chlorophototrophs currently are known to occur in seven bacterial phyla: Cyanobacteria, Proteobacteria, Chlorobi, Chloroflexi, Firmicutes, Acidobacteria, and Gemmatimonadetes. Other organisms that can produce chlorophylls and photochemical reaction centers may still be undiscovered. Here we summarize the current status of the taxonomy and phylogeny of chlorophototrophic bacteria as revealed by genomic methods. In specific cases, we briefly describe important ecophysiological and metabolic insights that have been gained from the application of genomic methods to these bacteria. In the 20 years since the completion of the Synechocystis sp. PCC 6803 genome in 1996, approximately 1,100 genomes have been sequenced, which represents nearly the complete diversity of known chlorophototrophic bacteria. These data are leading to new insights into many important processes, including photosynthesis, nitrogen and carbon fixation, cellular differentiation and development, symbiosis, and ecosystem functionality.
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Affiliation(s)
- Vera Thiel
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; ,
| | - Marcus Tank
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; ,
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA
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97
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de Lorenzo V. Environmental microbiology to the rescue of planet earth. Environ Microbiol 2018; 20:1910-1916. [DOI: 10.1111/1462-2920.14105] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Víctor de Lorenzo
- Systems Biology Department, Centro Nacional de Biotecnología‐CSIC, Campus de CantoblancoMadrid 28049 Spain
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98
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Pushkarev A, Hevroni G, Roitman S, Shim JG, Choi A, Jung KH, Béjà O. The Use of a Chimeric Rhodopsin Vector for the Detection of New Proteorhodopsins Based on Color. Front Microbiol 2018; 9:439. [PMID: 29593685 PMCID: PMC5859045 DOI: 10.3389/fmicb.2018.00439] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/26/2018] [Indexed: 11/20/2022] Open
Abstract
Student microbial ecology laboratory courses are often conducted as condensed courses in which theory and wet lab work are combined in a very intensive short time period. In last decades, the study of marine microbial ecology is increasingly reliant on molecular-based methods, and as a result many of the research projects conducted in such courses require sequencing that is often not available on site and may take more time than a typical course allows. In this work, we describe a protocol combining molecular and functional methods for analyzing proteorhodopsins (PRs), with visible results in only 4–5 days that do not rely on sequencing. PRs were discovered in oceanic surface waters two decades ago, and have since been observed in different marine environments and diverse taxa, including the abundant alphaproteobacterial SAR11 group. PR subgroups are currently known to absorb green and blue light, and their distribution was previously explained by prevailing light conditions – green pigments at the surface and blue pigments in deeper waters, as blue light travels deeper in the water column. To detect PR in environmental samples, we created a chimeric plasmid suitable for direct expression of PRs using PCR amplification and functional analysis in Escherichia coli cells. Using this assay, we discovered several exceptional cases of PRs whose phenotypes differed from those predicted based on sequence only, including a previously undescribed yellow-light absorbing PRs. We applied this assay in two 10-days marine microbiology courses and found it to greatly enhance students’ laboratory experience, enabling them to gain rapid visual feedback and colorful reward for their work. Furthermore we expect this assay to promote the use of functional assays for the discovery of new rhodopsin variants.
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Affiliation(s)
- Alina Pushkarev
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Gur Hevroni
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Sheila Roitman
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Jin-Gon Shim
- Department of Life Science and Institute of Biological Interfaces, Sogang University, Seoul, South Korea
| | - Ahreum Choi
- 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
| | - Oded Béjà
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
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99
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Kandori H, Inoue K, Tsunoda SP. Light-Driven Sodium-Pumping Rhodopsin: A New Concept of Active Transport. Chem Rev 2018. [DOI: 10.1021/acs.chemrev.7b00548] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
| | - Keiichi Inoue
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Satoshi P. Tsunoda
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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100
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Olson DK, Yoshizawa S, Boeuf D, Iwasaki W, DeLong EF. Proteorhodopsin variability and distribution in the North Pacific Subtropical Gyre. ISME JOURNAL 2018; 12:1047-1060. [PMID: 29476140 PMCID: PMC5864233 DOI: 10.1038/s41396-018-0074-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/21/2017] [Accepted: 12/05/2017] [Indexed: 11/17/2022]
Abstract
Proteorhodopsin is a light-activated retinal-containing proton pump found in many marine bacteria. These photoproteins are globally distributed in the ocean’s photic zone and are capable of generating a proton motive force across the cell membrane. We investigated the phylogenetic diversity, distribution, and abundance of proteorhodopsin encoding genes in free-living bacterioplankton in the North Pacific Subtropical Gyre, leveraging a gene catalog derived from metagenomic samples from the ocean’s surface to 1000 m depth. Proteorhodopsin genes were identified at all depths sampled, but were most abundant at depths shallower than 200 m. The majority of proteorhodopsin gene sequences (60.9%) belonged to members of the SAR11 lineage, with remaining sequences distributed among other diverse taxa. We observed variations in the conserved residues involved in ion pumping and spectral tuning, and biochemically confirmed four different proton pumping proteorhodopsin motifs, including one unique to deep-water SAR11. We also identified a new group of putative proteorhodopsins having unknown function. Our results reveal a broad organismal and unexpected depth distribution for different proteorhodopsin types, as well as substantial within-taxon variability. These data provide a framework for exploring the ecological relevance of proteorhodopsins and their spatiotemporal variation and function in heterotrophic bacteria in the open ocean.
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Affiliation(s)
- Daniel K Olson
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawaii, Honolulu, HI, 96822, USA
| | - Susumu Yoshizawa
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, 277-8564, Japan
| | - Dominique Boeuf
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawaii, Honolulu, HI, 96822, USA
| | - Wataru Iwasaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, 277-8564, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Edward F DeLong
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawaii, Honolulu, HI, 96822, USA.
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