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Rodero MDR, Magdalena JA, Steyer JP, Escudié R, Capson-Tojo G. Potential of enriched phototrophic purple bacteria for H 2 bioconversion into single cell protein. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168471. [PMID: 37951275 DOI: 10.1016/j.scitotenv.2023.168471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/20/2023] [Accepted: 11/08/2023] [Indexed: 11/13/2023]
Abstract
Single cell protein (SCP) has emerged as an alternative protein source, potentially based on the recovery of carbon and nutrients from waste-derived resources as part of the circular economy. From those resources, gaseous substrates have the advantage of an easy sterilization, allowing the production of pathogen-free SCP. Sterile gaseous substrates allow producing pathogen-free SCP. This study evaluated the use of an enriched phototrophic purple bacteria (PPB) consortium for SCP production using H2 and CO2 as electron and C sources. The influence of pH (6.0-8.5), temperature (15-50 °C) and light intensity (0-50 W·m-2) on the growth kinetics and biomass yields was investigated using batch tests. Optimal conditions were found at pH 7, 25 °C and light intensities over 30 W·m-2. High biomass and protein yields were achieved (~ 1 g CODbiomass·g CODH2consumed-1 and 3.9-4.4 g protein·g H2-1) regardless of the environmental conditions, being amongst the highest values reported from gaseous streams. These high yields were obtained thanks to the use of light as a sole energy source by the PPB consortium, allowing a total utilization of H2 for growth. Hydrogen uptake rates varied considerably, with values up to 61 ± 5 mg COD·d-1 for the overall H2 consumption rates and 2.00 ± 0.14 g COD·g COD-1·d-1 for the maximum specific uptake rates under optimal growth conditions. The latter value was estimated using a mechanistic model able to represent PPB growth on H2. The biomass exhibited high protein contents (>50 % w/w) and adequate amino acid profiles, showing its suitability as SCP for feed. PPB were the dominant bacteria during the experiments (relative abundance over 80 % in most tests), with a stable population dominated by Rhodobacter sp. and Rhodopseudomonas sp. This study demonstrates the potential of enriched PPB cultures for H2 bioconversion into SCP.
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Affiliation(s)
- María Del Rosario Rodero
- INRAE, Univ Montpellier, LBE, 102 Avenue des Etangs, 11100 Narbonne, France; Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain.
| | - Jose Antonio Magdalena
- INRAE, Univ Montpellier, LBE, 102 Avenue des Etangs, 11100 Narbonne, France; Vicerrectorado de Investigación y Transferencia de la Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | - Renaud Escudié
- INRAE, Univ Montpellier, LBE, 102 Avenue des Etangs, 11100 Narbonne, France
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2
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Fernández-Juárez V, Hallstrøm S, Pacherres CO, Wang J, Coll-Garcia G, Kühl M, Riemann L. Biofilm formation and cell plasticity drive diazotrophy in an anoxygenic phototrophic bacterium. Appl Environ Microbiol 2023; 89:e0102723. [PMID: 37882569 PMCID: PMC10686084 DOI: 10.1128/aem.01027-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/14/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE The contribution of non-cyanobacterial diazotrophs (NCDs) to total N2 fixation in the marine water column is unknown, but their importance is likely constrained by the limited availability of dissolved organic matter and low O2 conditions. Light could support N2 fixation and growth by NCDs, yet no examples from bacterioplankton exist. In this study, we show that the phototrophic NCD, Rhodopseudomonas sp. BAL398, which is a member of the diazotrophic community in the surface waters of the Baltic Sea, can utilize light. Our study highlights the significance of biofilm formation for utilizing light and fixing N2 under oxic conditions and the role of cell plasticity in regulating these processes. Our findings have implications for the general understanding of the ecology and importance of NCDs in marine waters.
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Affiliation(s)
- Víctor Fernández-Juárez
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Søren Hallstrøm
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Cesar O. Pacherres
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jiaqi Wang
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Guillem Coll-Garcia
- Microbiology, Biology Department, University of the Balearic Islands, Palma de Mallorca, Spain
- Environmental Microbiology Group, Mediterranean Institute for Advanced Studies (CSIC-UIB), Esporles, Spain
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lasse Riemann
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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3
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Tani K, Kanno R, Ji XC, Satoh I, Kobayashi Y, Hall M, Yu LJ, Kimura Y, Mizoguchi A, Humbel BM, Madigan MT, Wang-Otomo ZY. Rhodobacter capsulatus forms a compact crescent-shaped LH1-RC photocomplex. Nat Commun 2023; 14:846. [PMID: 36792596 PMCID: PMC9932092 DOI: 10.1038/s41467-023-36460-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
Rhodobacter (Rba.) capsulatus has been a favored model for studies of all aspects of bacterial photosynthesis. This purple phototroph contains PufX, a polypeptide crucial for dimerization of the light-harvesting 1-reaction center (LH1-RC) complex, but lacks protein-U, a U-shaped polypeptide in the LH1-RC of its close relative Rba. sphaeroides. Here we present a cryo-EM structure of the Rba. capsulatus LH1-RC purified by DEAE chromatography. The crescent-shaped LH1-RC exhibits a compact structure containing only 10 LH1 αβ-subunits. Four αβ-subunits corresponding to those adjacent to protein-U in Rba. sphaeroides were absent. PufX in Rba. capsulatus exhibits a unique conformation in its N-terminus that self-associates with amino acids in its own transmembrane domain and interacts with nearby polypeptides, preventing it from interacting with proteins in other complexes and forming dimeric structures. These features are discussed in relation to the minimal requirements for the formation of LH1-RC monomers and dimers, the spectroscopic behavior of both the LH1 and RC, and the bioenergetics of energy transfer from LH1 to the RC.
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Affiliation(s)
- Kazutoshi Tani
- Graduate School of Medicine, Mie University, Tsu, Japan.
| | - Ryo Kanno
- Scientific Imaging Section, Research Support Division, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1, Tancha, Onna-Son, Kunigami-Gun, Okinawa, Japan.,Quantum wave microscopy unit, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1, Tancha, Onna-Son, Kunigami-Gun, Okinawa, Japan
| | | | | | | | - Malgorzata Hall
- Scientific Imaging Section, Research Support Division, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1, Tancha, Onna-Son, Kunigami-Gun, Okinawa, Japan
| | - Long-Jiang Yu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yukihiro Kimura
- Department of Agrobioscience, Graduate School of Agriculture, Kobe University, Nada, Kobe, Japan
| | | | - Bruno M Humbel
- Scientific Imaging Section, Research Support Division, Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1, Tancha, Onna-Son, Kunigami-Gun, Okinawa, Japan.,Department of Cell Biology and Neuroscience, Juntendo University, Graduate School of Medicine, Tokyo, Japan
| | - Michael T Madigan
- School of Biological Sciences, Department of Microbiology, Southern Illinois University, Carbondale, IL, USA
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4
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Purple bacteria screening for photoautohydrogenotrophic food production: Are new H 2-fed isolates faster and nutritionally better than photoheterotrophically obtained reference species? N Biotechnol 2022; 72:38-47. [PMID: 36049649 DOI: 10.1016/j.nbt.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/26/2022] [Accepted: 08/28/2022] [Indexed: 12/14/2022]
Abstract
Photoautohydrogenotrophic enrichments of wastewater treatment microbiomes were performed to obtain hypothetically high-potential specialist species for biotechnological applications. From these enrichment cultures, ten photoautohydrogenotrophic species were isolated: six Rhodopseudomonas species, three Rubrivivax members and Rhodobacter blasticus. The performance of these isolates was compared to three commonly studied, and originally photoheterotrophically enriched species (Rhodopseudomonas palustris, Rhodobacter capsulatus and Rhodobacter sphaeroides), designated as reference species. Repeated subcultivations were applied to improve the initial poor performance of the isolates (acclimation effect), which resulted in increases in both maximum growth rate and protein productivity. However, the maximum growth rate of the reference species remained 3-7 times higher compared to the isolates (0.42-0.84 d-1 at 28 °C), while protein productivities remained 1.5-1.7 times higher. This indicated that H2-based enrichment did not result in photoautohydrogenotrophic specialists, suggesting that the reference species are more suitable for intensified biomass and protein production. On the other hand, the isolates were able to provide equally high protein quality profiles as the references species, providing full dietary essential amino acid matches for human food. Lastly, the effect of metabolic carbon/electron switching (back and forth between auto- to heterotrophic conditions) initially boosted µmax when returning to photoautohydrogenotrophic conditions. However, the switch negatively impacted lag phase, protein productivities and pigment contents. In the case of protein productivity, the acquired acclimation was partially lost with decreases of up to 44 % and 40 % respectively for isolates and reference species. Finally, the three reference species, and specifically Rh. capsulatus, remained the most suitable candidate(s) for further biotechnological development.
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5
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Beaver K, Gaffney EM, Minteer SD. Understanding metabolic bioelectrocatalysis of the purple bacterium Rhodobacter capsulatus through substrate modulation. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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6
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Yu J, Moon SK, Kim YH, Min J. Isoprene production by Rhodobacter sphaeroides and its antimicrobial activity. Res Microbiol 2022; 173:103938. [DOI: 10.1016/j.resmic.2022.103938] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/02/2022] [Accepted: 03/09/2022] [Indexed: 11/25/2022]
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Alloul A, Spanoghe J, Machado D, Vlaeminck SE. Unlocking the genomic potential of aerobes and phototrophs for the production of nutritious and palatable microbial food without arable land or fossil fuels. Microb Biotechnol 2022; 15:6-12. [PMID: 33529492 PMCID: PMC8719805 DOI: 10.1111/1751-7915.13747] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 12/24/2020] [Indexed: 01/04/2023] Open
Abstract
The increasing world population and living standards urgently necessitate the transition towards a sustainable food system. One solution is microbial protein, i.e. using microbial biomass as alternative protein source for human nutrition, particularly based on renewable electron and carbon sources that do not require arable land. Upcoming green electrification and carbon capture initiatives enable this, yielding new routes to H2, CO2 and CO2-derived compounds like methane, methanol, formic- and acetic acid. Aerobic hydrogenotrophs, methylotrophs, acetotrophs and microalgae are the usual suspects for nutritious and palatable biomass production on these compounds. Interestingly, these compounds are largely un(der)explored for purple non-sulfur bacteria, even though these microbes may be suitable for growing aerobically and phototrophically on these substrates. Currently, selecting the best strains, metabolisms and cultivation conditions for nutritious and palatable microbial food mainly starts from empirical growth experiments, and mostly does not stretch beyond bulk protein. We propose a more target-driven and efficient approach starting from the genome-embedded potential to tuning towards, for instance, essential amino- and fatty acids, vitamins, taste,... Genome-scale metabolic models combined with flux balance analysis will facilitate this, narrowing down experimental variations and enabling to get the most out of the 'best' combinations of strain and electron and carbon sources.
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Affiliation(s)
- Abbas Alloul
- Research Group of Sustainable Energy, Air and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 171Antwerpen2020Belgium
| | - Janne Spanoghe
- Research Group of Sustainable Energy, Air and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 171Antwerpen2020Belgium
| | - Daniel Machado
- Department of Biotechnology and Food ScienceNorwegian University of Science and TechnologyTrondheim7491Norway
| | - Siegfried E. Vlaeminck
- Research Group of Sustainable Energy, Air and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 171Antwerpen2020Belgium
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8
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Kumar Sharma A, Kumar Ghodke P, Manna S, Chen WH. Emerging technologies for sustainable production of biohydrogen production from microalgae: A state-of-the-art review of upstream and downstream processes. BIORESOURCE TECHNOLOGY 2021; 342:126057. [PMID: 34597808 DOI: 10.1016/j.biortech.2021.126057] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/23/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Biohydrogen (BioH2) is considered as one of the most environmentally friendly fuels and a strong candidate to meet the future demand for a sustainable source of energy. Presently, the production of BioH2 from photosynthetic organisms has raised a lot of hopes in the fuel industry. Moreover, microalgal-based BioH2 synthesis not only helps to combat current global warming by capturing greenhouse gases but also plays a key role in wastewater treatment. Hence, this manuscript provides a state-of-the-art review of the upstream and downstream BioH2 production processes. Different metabolic routes such as direct and indirect photolysis, dark fermentation, photofermentation, and microbial electrolysis are covered in detail. Upstream processes (e.g. growth techniques, growth media) also have a great impact on BioH2 productivity and economics, which is also explored. Technical and scientific obstacles of microalgae BioH2 systems are finally addressed, allowing the technology to become more innovative and commercial.
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Affiliation(s)
- Amit Kumar Sharma
- Department of Chemistry, Centre for Alternate and Renewable Energy Research, R&D, University of Petroleum & Energy Studies (UPES), School of Engineering, Energy Acres Building, Bidholi, Dehradun 248007, Uttarakhand, India
| | - Praveen Kumar Ghodke
- Department of Chemical Engineering, National Institute of Technology Calicut, Kozhikode 673601, Kerala, India
| | - Suvendu Manna
- Department of Health Safety, Environment and Civil Engineering, University of Petroleum and Energy Studies, Dehradun, Uttarakhand 248007, India
| | - Wei-Hsin Chen
- Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan; Department of Mechanical Engineering, National Chin-Yi University of Technology, Taichung 411, Taiwan.
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9
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Spanoghe J, Vermeir P, Vlaeminck SE. Microbial food from light, carbon dioxide and hydrogen gas: Kinetic, stoichiometric and nutritional potential of three purple bacteria. BIORESOURCE TECHNOLOGY 2021; 337:125364. [PMID: 34120062 DOI: 10.1016/j.biortech.2021.125364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 06/12/2023]
Abstract
The urgency for a protein transition towards more sustainable solutions is one of the major societal challenges. Microbial protein is one of the alternative routes, in which land- and fossil-free production should be targeted. The photohydrogenotrophic growth of purple bacteria, which builds on the H2- and CO2-economy, is unexplored for its microbial protein potential. The three tested species (Rhodobacter capsulatus, Rhodobacter sphaeroides and Rhodopseudomonas palustris) obtained promising growth rates (2.3-2.7 d-1 at 28°C) and protein productivities (0.09-0.12 g protein L-1 d-1), rendering them likely faster and more productive than microalgae. The achieved protein yields (2.6-2.9 g protein g-1 H2) transcended the ones of aerobic hydrogen oxidizing bacteria. Furthermore, all species provided full dietary protein matches for humans and their fatty acid content was dominated by vaccenic acid (82-86%). Given its kinetic and nutritional performance we recommend to consider Rhodobacter capsulatus as a high-potential sustainable source of microbial food.
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Affiliation(s)
- Janne Spanoghe
- Research Group of Sustainable Energy, Air and Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, Antwerpen 2020, Belgium
| | - Pieter Vermeir
- Laboratory for Chemical Analysis, Department of Green Chemistry and Technology, Ghent University, Valentin Vaerwyckweg 1, Gent 9000, Belgium
| | - Siegfried E Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology (DuEL), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, Antwerpen 2020, Belgium.
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10
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Alloul A, Cerruti M, Adamczyk D, Weissbrodt DG, Vlaeminck SE. Operational Strategies to Selectively Produce Purple Bacteria for Microbial Protein in Raceway Reactors. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8278-8286. [PMID: 34085818 DOI: 10.1021/acs.est.0c08204] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Purple non-sulfur bacteria (PNSB) show potential for microbial protein production on wastewater as animal feed. They offer good selectivity (i.e., low microbial diversity and high abundance of one species) when grown anaerobically in the light. However, the cost of closed anaerobic photobioreactors is prohibitive for protein production. Although open raceway reactors are cheaper, their feasibility to selectively grow PNSB is thus far unexplored. This study developed operational strategies to boost PNSB abundance in the biomass of a raceway reactor fed with volatile fatty acids. For a flask reactor run at a 2 day sludge retention time (SRT), matching the chemical oxygen demand (COD) loading rate to the removal rate in the light period prevented substrate availability during the dark period and increased the PNSB abundance from 50-67 to 88-94%. A raceway reactor run at a 2 day SRT showed an increased PNSB abundance from 14 to 56% when oxygen supply was reduced (no stirring at night). The best performance was achieved at the highest surface-to-volume ratio (10 m2 m-3 increased light availability) showing productivities up to 0.2 g protein L-1 day-1 and a PNSB abundance of 78%. This study pioneered in PNSB-based microbial protein production in raceway reactors, yielding high selectivity while avoiding the combined availability of oxygen, COD, and darkness.
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Affiliation(s)
- Abbas Alloul
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - Marta Cerruti
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Damian Adamczyk
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - David G Weissbrodt
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Siegfried E Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
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11
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Fradinho J, Allegue LD, Ventura M, Melero JA, Reis MAM, Puyol D. Up-scale challenges on biopolymer production from waste streams by Purple Phototrophic Bacteria mixed cultures: A critical review. BIORESOURCE TECHNOLOGY 2021; 327:124820. [PMID: 33578354 DOI: 10.1016/j.biortech.2021.124820] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 06/12/2023]
Abstract
The increasing volume of waste streams require new biological technologies that can address pollution concerns while offering sustainable products. Purple phototrophic bacteria (PPB) are very versatile organisms that present a unique metabolism that allows them to adapt to a variety of environments, including the most complex waste streams. Their successful adaptation to such demanding conditions is partly the result of internal polymers accumulation which can be stored for electron/energy balance or as carbon and nutrients reserves for deprivation periods. Polyhydroxyalkanoates, glycogen, sulphur and polyphosphate are examples of polymers produced by PPB that can be economically explored due to their applications in the plastic, energy and fertilizers sectors. Their large-scale production implies the outdoor operation of PPB systems which brings new challenges, identified in this review. An overview of the current PPB polymer producing technologies and prospects for their future development is also provided.
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Affiliation(s)
- J Fradinho
- UCIBIO-REQUIMTE, Department of Chemistry, Faculty of Sciences and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - L D Allegue
- Group of Chemical and Environmental Engineering (GIQA), Higher School of Experimental Sciences and Technology (ESCET), Universidad Rey Juan Carlos, 28933 Móstoles, Madrid, Spain
| | - M Ventura
- Group of Chemical and Environmental Engineering (GIQA), Higher School of Experimental Sciences and Technology (ESCET), Universidad Rey Juan Carlos, 28933 Móstoles, Madrid, Spain
| | - J A Melero
- Group of Chemical and Environmental Engineering (GIQA), Higher School of Experimental Sciences and Technology (ESCET), Universidad Rey Juan Carlos, 28933 Móstoles, Madrid, Spain
| | - M A M Reis
- UCIBIO-REQUIMTE, Department of Chemistry, Faculty of Sciences and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - D Puyol
- Group of Chemical and Environmental Engineering (GIQA), Higher School of Experimental Sciences and Technology (ESCET), Universidad Rey Juan Carlos, 28933 Móstoles, Madrid, Spain.
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12
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Cerruti M, Stevens B, Ebrahimi S, Alloul A, Vlaeminck SE, Weissbrodt DG. Enrichment and Aggregation of Purple Non-sulfur Bacteria in a Mixed-Culture Sequencing-Batch Photobioreactor for Biological Nutrient Removal From Wastewater. Front Bioeng Biotechnol 2021; 8:557234. [PMID: 33392158 PMCID: PMC7773948 DOI: 10.3389/fbioe.2020.557234] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022] Open
Abstract
Mixed-culture biotechnologies are widely used to capture nutrients from wastewater. Purple non-sulfur bacteria (PNSB), a guild of anoxygenic photomixotrophic organisms, rise interest for their ability to directly assimilate nutrients in the biomass. One challenge targets the aggregation and accumulation of PNSB biomass to separate it from the treated water. Our aim was to enrich and produce a concentrated, fast-settling PNSB biomass with high nutrient removal capacity in a 1.5-L, stirred-tank, anaerobic sequencing-batch photobioreactor (SBR). PNSB were rapidly enriched after inoculation with activated sludge at 0.1 gVSS L-1 in a first batch of 24 h under continuous irradiance of infrared (IR) light (>700 nm) at 375 W m-2, with Rhodobacter reaching 54% of amplicon sequencing read counts. SBR operations with decreasing hydraulic retention times (48 to 16 h, i.e., 1-3 cycles d-1) and increasing volumetric organic loading rates (0.2-1.3 kg COD d-1 m-3) stimulated biomass aggregation, settling, and accumulation in the system, reaching as high as 3.8 g VSS L-1. The sludge retention time (SRT) increased freely from 2.5 to 11 days. Acetate, ammonium, and orthophosphate were removed up to 96% at a rate of 1.1 kg COD d-1 m-3, 77% at 113 g N d-1 m-3, and 73% at 15 g P d-1 m-3, respectively, with COD:N:P assimilation ratio of 100:6.7:0.9 m/m/m. SBR regime shifts sequentially selected for Rhodobacter (90%) under shorter SRT and non-limiting concentration of acetate during reaction phases, for Rhodopseudomonas (70%) under longer SRT and acetate limitation during reaction, and Blastochloris (10%) under higher biomass concentrations, underlying competition for substrate and photons in the PNSB guild. With SBR operations we produced a fast-settling biomass, highly (>90%) enriched in PNSB. A high nutrient removal was achieved by biomass assimilation, reaching the European nutrient discharge limits. We opened further insights on the microbial ecology of PNSB-based processes for water resource recovery.
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Affiliation(s)
- Marta Cerruti
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Berber Stevens
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Sirous Ebrahimi
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands.,Department of Chemical Engineering, Sahand University of Technology, Tabriz, Iran
| | - Abbas Alloul
- Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | | | - David G Weissbrodt
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
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13
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Sakarika M, Spanoghe J, Sui Y, Wambacq E, Grunert O, Haesaert G, Spiller M, Vlaeminck SE. Purple non-sulphur bacteria and plant production: benefits for fertilization, stress resistance and the environment. Microb Biotechnol 2020; 13:1336-1365. [PMID: 31432629 PMCID: PMC7415370 DOI: 10.1111/1751-7915.13474] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/23/2019] [Accepted: 07/26/2019] [Indexed: 11/28/2022] Open
Abstract
Purple non-sulphur bacteria (PNSB) are phototrophic microorganisms, which increasingly gain attention in plant production due to their ability to produce and accumulate high-value compounds that are beneficial for plant growth. Remarkable features of PNSB include the accumulation of polyphosphate, the production of pigments and vitamins and the production of plant growth-promoting substances (PGPSs). Scattered case studies on the application of PNSB for plant cultivation have been reported for decades, yet a comprehensive overview is lacking. This review highlights the potential of using PNSB in plant production, with emphasis on three key performance indicators (KPIs): fertilization, resistance to stress (biotic and abiotic) and environmental benefits. PNSB have the potential to enhance plant growth performance, increase the yield and quality of edible plant biomass, boost the resistance to environmental stresses, bioremediate heavy metals and mitigate greenhouse gas emissions. Here, the mechanisms responsible for these attributes are discussed. A distinction is made between the use of living and dead PNSB cells, where critical interpretation of existing literature revealed the better performance of living cells. Finally, this review presents research gaps that remain yet to be elucidated and proposes a roadmap for future research and implementation paving the way for a more sustainable crop production.
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Affiliation(s)
- Myrsini Sakarika
- Research Group of Sustainable Air, Energy and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Janne Spanoghe
- Research Group of Sustainable Air, Energy and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Yixing Sui
- Research Group of Sustainable Air, Energy and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Eva Wambacq
- Department of Plants and CropsFaculty of Bioscience EngineeringGhent UniversityV. Vaerwyckweg 19000GhentBelgium
| | - Oliver Grunert
- Greenyard Horticulture Belgium NVSkaldenstraat 7a9042GentBelgium
| | - Geert Haesaert
- Department of Plants and CropsFaculty of Bioscience EngineeringGhent UniversityV. Vaerwyckweg 19000GhentBelgium
| | - Marc Spiller
- Research Group of Sustainable Air, Energy and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
| | - Siegfried E. Vlaeminck
- Research Group of Sustainable Air, Energy and Water TechnologyDepartment of Bioscience EngineeringUniversity of AntwerpGroenenborgerlaan 1712020AntwerpenBelgium
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14
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Sass K, Güllert S, Streit WR, Perner M. A hydrogen-oxidizing bacterium enriched from the open ocean resembling a symbiont. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:396-405. [PMID: 32338395 DOI: 10.1111/1758-2229.12847] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 03/31/2020] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
A new autotrophic hydrogen-oxidizing Chromatiaceae bacterium, namely bacterium CTD079, was enriched from a water column sample at 1500 m water depth in the southern Pacific Ocean. Based on the phylogeny of 16S rRNA genes, it was closely related to a scaly snail endosymbiont (99.2% DNA sequence identity) whose host so far is only known to colonize hydrothermal vents along the Indian ridge. The average nucleotide identity between the genomes of CTD079 and the snail endosymbiont was 91%. The observed differences likely reflect adaptations to their specific habitats. For example, CTD079 encodes additional enzymes like the formate dehydrogenase increasing the organism's spectrum of energy generation pathways. Other additional physiological features of CTD079 included the increase of viral defence strategies, secretion systems and specific transporters for essential elements. These important genome characteristics suggest an adaptation to life in the open ocean.
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Affiliation(s)
- Katharina Sass
- Molecular Biology of Microbial Consortia, Universität Hamburg, Hamburg, Germany
- Microbiology and Biotechnology, Universität Hamburg, Hamburg, Germany
| | - Simon Güllert
- Microbiology and Biotechnology, Universität Hamburg, Hamburg, Germany
| | - Wolfgang R Streit
- Microbiology and Biotechnology, Universität Hamburg, Hamburg, Germany
| | - Mirjam Perner
- Molecular Biology of Microbial Consortia, Universität Hamburg, Hamburg, Germany
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15
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Kawai S, Nishihara A, Matsuura K, Haruta S. Hydrogen-dependent autotrophic growth in phototrophic and chemolithotrophic cultures of thermophilic bacteria, Chloroflexus aggregans and Chloroflexus aurantiacus, isolated from Nakabusa hot springs. FEMS Microbiol Lett 2020; 366:5510454. [PMID: 31158281 DOI: 10.1093/femsle/fnz122] [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] [Received: 01/14/2019] [Accepted: 06/01/2019] [Indexed: 11/14/2022] Open
Abstract
The genus Chloroflexus is a deeply branching group of thermophilic filamentous anoxygenic phototrophic bacteria. The bacteria in this genus have been shown to grow well heterotrophically under anaerobic photosynthetic and aerobic respiratory conditions. We examined autotrophic growth in new isolates of Chloroflexus strains from hot springs in Nakabusa, Japan. The isolates belonging to Chloroflexus aggregans (98.7% identity of 16S rRNA gene sequence to the respective type strain) and Chloroflexus aurantiacus (99.9% identity to the respective type strain) grew photoautotrophically under a 24% H2 atmosphere. We also observed chemolithotrophic growth of these isolates under 80% H2 and 5% O2 conditions in the dark. This is the first report showing that Chloroflexus grew under both photoautotrophic and chemolithotrophic conditions in addition to photoheterotrophic and aerobic chemoheterotrophic conditions.
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Affiliation(s)
- Shigeru Kawai
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Arisa Nishihara
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Katsumi Matsuura
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Shin Haruta
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
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16
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Orsi E, Folch PL, Monje-López VT, Fernhout BM, Turcato A, Kengen SWM, Eggink G, Weusthuis RA. Characterization of heterotrophic growth and sesquiterpene production by Rhodobacter sphaeroides on a defined medium. J Ind Microbiol Biotechnol 2019; 46:1179-1190. [PMID: 31187318 PMCID: PMC6697705 DOI: 10.1007/s10295-019-02201-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/29/2019] [Indexed: 11/30/2022]
Abstract
Rhodobacter sphaeroides is a metabolically versatile bacterium capable of producing terpenes natively. Surprisingly, terpene biosynthesis in this species has always been investigated in complex media, with unknown compounds possibly acting as carbon and nitrogen sources. Here, a defined medium was adapted for R. sphaeroides dark heterotrophic growth, and was used to investigate the conversion of different organic substrates into the reporter terpene amorphadiene. The amorphadiene synthase was cloned in R. sphaeroides, allowing its biosynthesis via the native 2-methyl-d-erythritol-4-phosphate (MEP) pathway and, additionally, via a heterologous mevalonate one. The latter condition increased titers up to eightfold. Consequently, better yields and productivities to previously reported complex media cultivations were achieved. Productivity was further investigated under different cultivation conditions, including nitrogen and oxygen availability. This novel cultivation setup provided useful insight into the understanding of terpene biosynthesis in R. sphaeroides, allowing to better comprehend its dynamics and regulation during chemoheterotrophic cultivation.
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Affiliation(s)
- Enrico Orsi
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Pauline L Folch
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Vicente T Monje-López
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Bas M Fernhout
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Alessandro Turcato
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Servé W M Kengen
- Laboratory of Microbiology, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands
| | - Gerrit Eggink
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands.,Biobased Products Food and Biobased Research, Wageningen University and Research, Wageningen, The Netherlands
| | - Ruud A Weusthuis
- Bioprocess Engineering, Department of Agrotechnology and Food, Wageningen University and Research, Wageningen, The Netherlands.
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17
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Martin WF, Bryant DA, Beatty JT. A physiological perspective on the origin and evolution of photosynthesis. FEMS Microbiol Rev 2018; 42:205-231. [PMID: 29177446 PMCID: PMC5972617 DOI: 10.1093/femsre/fux056] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/20/2017] [Indexed: 12/22/2022] Open
Abstract
The origin and early evolution of photosynthesis are reviewed from an ecophysiological perspective. Earth's first ecosystems were chemotrophic, fueled by geological H2 at hydrothermal vents and, required flavin-based electron bifurcation to reduce ferredoxin for CO2 fixation. Chlorophyll-based phototrophy (chlorophototrophy) allowed autotrophs to generate reduced ferredoxin without electron bifurcation, providing them access to reductants other than H2. Because high-intensity, short-wavelength electromagnetic radiation at Earth's surface would have been damaging for the first chlorophyll (Chl)-containing cells, photosynthesis probably arose at hydrothermal vents under low-intensity, long-wavelength geothermal light. The first photochemically active pigments were possibly Zn-tetrapyrroles. We suggest that (i) after the evolution of red-absorbing Chl-like pigments, the first light-driven electron transport chains reduced ferredoxin via a type-1 reaction center (RC) progenitor with electrons from H2S; (ii) photothioautotrophy, first with one RC and then with two, was the bridge between H2-dependent chemolithoautotrophy and water-splitting photosynthesis; (iii) photothiotrophy sustained primary production in the photic zone of Archean oceans; (iv) photosynthesis arose in an anoxygenic cyanobacterial progenitor; (v) Chl a is the ancestral Chl; and (vi), anoxygenic chlorophototrophic lineages characterized so far acquired, by horizontal gene transfer, RCs and Chl biosynthesis with or without autotrophy, from the architects of chlorophototrophy-the cyanobacterial lineage.
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Affiliation(s)
- William F Martin
- Institute for Molecular Evolution, University of Düsseldorf, D-40225 Düsseldorf, Germany
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - J Thomas Beatty
- Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
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18
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Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments. WATER 2017. [DOI: 10.3390/w9020108] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Park JY, Kim YH, Min J. CO2 reduction and organic compounds production by photosynthetic bacteria with surface displayed carbonic anhydrase and inducible expression of phosphoenolpyruvate carboxylase. Enzyme Microb Technol 2017; 96:103-110. [DOI: 10.1016/j.enzmictec.2016.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/05/2016] [Accepted: 10/11/2016] [Indexed: 11/30/2022]
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20
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Wecker MS, Beaton SE, Chado RA, Ghirardi ML. Development of a
Rhodobacter capsulatus
self‐reporting model system for optimizing light‐dependent, [FeFe]‐hydrogenase‐driven H
2
production. Biotechnol Bioeng 2016; 114:291-297. [DOI: 10.1002/bit.26076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/29/2016] [Accepted: 08/08/2016] [Indexed: 11/07/2022]
Affiliation(s)
| | - Stephen E. Beaton
- United States Air Force AcademyDepartment of ChemistryColorado SpringsColorado
| | - Robert A. Chado
- United States Air Force AcademyDepartment of ChemistryColorado SpringsColorado
| | - Maria L. Ghirardi
- National Renewable Energy LaboratoryMS 3313, 15013 Denver West ParkwayGoldenColorado80401
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21
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Magdaong NCM, Niedzwiedzki DM, Goodson C, Blankenship RE. Carotenoid-to-Bacteriochlorophyll Energy Transfer in the LH1–RC Core Complex of a Bacteriochlorophyll b Containing Purple Photosynthetic Bacterium Blastochloris viridis. J Phys Chem B 2016; 120:5159-71. [DOI: 10.1021/acs.jpcb.6b04307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikki Cecil M. Magdaong
- Department
of Biology, Washington University in Saint Louis, One Brookings
Drive, St. Louis, Missouri 63130 United States
- Department of Chemistry, Washington University in Saint Louis, One Brookings Drive, St.
Louis, Missouri 63130 United States
- Photosynthetic
Antenna Research Center, Washington University in Saint Louis, One Brookings
Drive, St. Louis, Missouri 63130 United States
| | - Dariusz M. Niedzwiedzki
- Photosynthetic
Antenna Research Center, Washington University in Saint Louis, One Brookings
Drive, St. Louis, Missouri 63130 United States
| | - Carrie Goodson
- Department
of Biology, Washington University in Saint Louis, One Brookings
Drive, St. Louis, Missouri 63130 United States
| | - Robert E. Blankenship
- Department
of Biology, Washington University in Saint Louis, One Brookings
Drive, St. Louis, Missouri 63130 United States
- Department of Chemistry, Washington University in Saint Louis, One Brookings Drive, St.
Louis, Missouri 63130 United States
- Photosynthetic
Antenna Research Center, Washington University in Saint Louis, One Brookings
Drive, St. Louis, Missouri 63130 United States
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22
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Fennema D, Phillips IR, Shephard EA. Trimethylamine and Trimethylamine N-Oxide, a Flavin-Containing Monooxygenase 3 (FMO3)-Mediated Host-Microbiome Metabolic Axis Implicated in Health and Disease. ACTA ACUST UNITED AC 2016; 44:1839-1850. [PMID: 27190056 PMCID: PMC5074467 DOI: 10.1124/dmd.116.070615] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 05/13/2016] [Indexed: 02/06/2023]
Abstract
Flavin-containing monooxygenase 3 (FMO3) is known primarily as an enzyme involved in the metabolism of therapeutic drugs. On a daily basis, however, we are exposed to one of the most abundant substrates of the enzyme trimethylamine (TMA), which is released from various dietary components by the action of gut bacteria. FMO3 converts the odorous TMA to nonodorous TMA N-oxide (TMAO), which is excreted in urine. Impaired FMO3 activity gives rise to the inherited disorder primary trimethylaminuria (TMAU). Affected individuals cannot produce TMAO and, consequently, excrete large amounts of TMA. A dysbiosis in gut bacteria can give rise to secondary TMAU. Recently, there has been much interest in FMO3 and its catalytic product, TMAO, because TMAO has been implicated in various conditions affecting health, including cardiovascular disease, reverse cholesterol transport, and glucose and lipid homeostasis. In this review, we consider the dietary components that can give rise to TMA, the gut bacteria involved in the production of TMA from dietary precursors, the metabolic reactions by which bacteria produce and use TMA, and the enzymes that catalyze the reactions. Also included is information on bacteria that produce TMA in the oral cavity and vagina, two key microbiome niches that can influence health. Finally, we discuss the importance of the TMA/TMAO microbiome-host axis in health and disease, considering factors that affect bacterial production and host metabolism of TMA, the involvement of TMAO and FMO3 in disease, and the implications of the host-microbiome axis for management of TMAU.
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Affiliation(s)
- Diede Fennema
- Institute of Structural and Molecular Biology, University College London (D.F., I.R.P., E.A.S.), and School of Biological and Chemical Sciences, Queen Mary University of London (I.R.P.), London, United Kingdom
| | - Ian R Phillips
- Institute of Structural and Molecular Biology, University College London (D.F., I.R.P., E.A.S.), and School of Biological and Chemical Sciences, Queen Mary University of London (I.R.P.), London, United Kingdom
| | - Elizabeth A Shephard
- Institute of Structural and Molecular Biology, University College London (D.F., I.R.P., E.A.S.), and School of Biological and Chemical Sciences, Queen Mary University of London (I.R.P.), London, United Kingdom
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23
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Cúcio C, Engelen AH, Costa R, Muyzer G. Rhizosphere Microbiomes of European + Seagrasses Are Selected by the Plant, But Are Not Species Specific. Front Microbiol 2016; 7:440. [PMID: 27065991 PMCID: PMC4815253 DOI: 10.3389/fmicb.2016.00440] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/18/2016] [Indexed: 11/13/2022] Open
Abstract
Seagrasses are marine flowering plants growing in soft-body sediments of intertidal and shallow sub-tidal zones. They play an important role in coastal ecosystems by stabilizing sediments, providing food and shelter for animals, and recycling nutrients. Like other plants, seagrasses live intimately with both beneficial and unfavorable microorganisms. Although much is known about the microbiomes of terrestrial plants, little is known about the microbiomes of seagrasses. Here we present the results of a detailed study on the rhizosphere microbiome of seagrass species across the North-eastern Atlantic Ocean: Zostera marina, Zostera noltii, and Cymodocea nodosa. High-resolution amplicon sequencing of 16S rRNA genes showed that the rhizobiomes were significantly different from the bacterial communities of surrounding bulk sediment and seawater. Although we found no significant differences between the rhizobiomes of different seagrass species within the same region, those of seagrasses in different geographical locations differed strongly. These results strongly suggest that the seagrass rhizobiomes are shaped by plant metabolism, but not coevolved with their host. The core rhizobiome of seagrasses includes mostly bacteria involved in the sulfur cycle, thereby highlighting the importance of sulfur-related processes in seagrass ecosystems.
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Affiliation(s)
- Catarina Cúcio
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands
| | - Aschwin H. Engelen
- Marine Ecology and Evolution Research Group, Centro de Ciencias do Mar, Universidade do AlgarveFaro, Portugal
| | - Rodrigo Costa
- Microbial Ecology and Evolution Research Group, Centro de Ciencias do Mar, Universidade do AlgarveFaro, Portugal
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, Netherlands
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24
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Zepeda Mendoza ML, Lundberg J, Ivarsson M, Campos P, Nylander JAA, Sallstedt T, Dalen L. Metagenomic Analysis from the Interior of a Speleothem in Tjuv-Ante's Cave, Northern Sweden. PLoS One 2016; 11:e0151577. [PMID: 26985997 PMCID: PMC4795671 DOI: 10.1371/journal.pone.0151577] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 03/01/2016] [Indexed: 02/01/2023] Open
Abstract
Speleothems are secondary mineral deposits normally formed by water supersaturated with calcium carbonate percolating into underground caves, and are often associated with low-nutrient and mostly non-phototrophic conditions. Tjuv-Ante's cave is a shallow-depth cave formed by the action of waves, with granite and dolerite as major components, and opal-A and calcite as part of the speleothems, making it a rare kind of cave. We generated two DNA shotgun sequencing metagenomic datasets from the interior of a speleothem from Tjuv-Ante's cave representing areas of old and relatively recent speleothem formation. We used these datasets to perform i) an evaluation of the use of these speleothems as past biodiversity archives, ii) functional and taxonomic profiling of the speleothem's different formation periods, and iii) taxonomic comparison of the metagenomic results to previous microscopic analyses from a nearby speleothem of the same cave. Our analyses confirm the abundance of Actinobacteria and fungi as previously reported by microscopic analyses on this cave, however we also discovered a larger biodiversity. Interestingly, we identified photosynthetic genes, as well as genes related to iron and sulphur metabolism, suggesting the presence of chemoautotrophs. Furthermore, we identified taxa and functions related to biomineralization. However, we could not confidently establish the use of this type of speleothems as biological paleoarchives due to the potential leaching from the outside of the cave and the DNA damage that we propose has been caused by the fungal chemical etching.
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Affiliation(s)
| | - Johannes Lundberg
- Department of Botany, Swedish Museum of Natural History, Stockholm, Sweden
| | - Magnus Ivarsson
- Department of Palaeobiology and the Nordic Center for Earth Evolution (NordCEE), Swedish Museum of Natural History, Stockholm, Sweden
| | - Paula Campos
- Centre for GeoGenetics, University of Copenhagen, Natural History Museum of Denmark, Copenhagen, Denmark
| | - Johan A. A. Nylander
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
| | - Therese Sallstedt
- Department of Palaeobiology and the Nordic Center for Earth Evolution (NordCEE), Swedish Museum of Natural History, Stockholm, Sweden
| | - Love Dalen
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
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25
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Omairi T, Wainwright M. Fluorescent minerals--A potential source of UV protection and visible light for the growth of green algae and cyanobacteria in extreme cosmic environments. LIFE SCIENCES IN SPACE RESEARCH 2015; 6:87-91. [PMID: 26256632 DOI: 10.1016/j.lssr.2015.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 07/03/2015] [Accepted: 07/06/2015] [Indexed: 06/04/2023]
Abstract
We propose that green algae (Chlorella variabilis and Dunaliella tertiolecta) and cyanobacteria (Synechococcus elongatus and Nostoc commune) can grow inside fluorescent rock minerals which convert damaging UV light to visible light, thereby allowing these organisms to survive and thrive in UV-rich environments without (or with limited) visible light, which would otherwise be inimical to them. The four microorganisms were incubated inside fluorescent rocks composed of fluorite, calcite and pyrite. The resultant growth was then measured following exposure to UV radiation, with the use of optical density and measurement of chlorophyll concentration. Results show that the microorganisms were shielded from harmful UV in these semi-transparent rocks, while at the same time benefiting from the fact that the minerals converted UV to visible light; this have been shown by a statistically significant increase in their growth, which although lower than when the cells were incubated in sunlight, was significantly higher than in controls incubated in the dark.
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Affiliation(s)
- Tareq Omairi
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Milton Wainwright
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
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26
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Khan NE, Nybo SE, Chappell J, Curtis WR. Triterpene hydrocarbon production engineered into a metabolically versatile host--Rhodobacter capsulatus. Biotechnol Bioeng 2015; 112:1523-32. [PMID: 25728701 DOI: 10.1002/bit.25573] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/14/2015] [Accepted: 02/11/2015] [Indexed: 11/08/2022]
Abstract
Triterpene hydrocarbon biosynthesis of the ancient algae Botryococcus braunii was installed into Rhodobacter capsulatus to explore the production of C30 hydrocarbon in a host capable of diverse growth habits-utilizing carbohydrate, sunlight or hydrogen (with CO2 fixation) as alternative energy feedstocks. Engineering an enhanced MEP pathway was also used to augment triterpene accumulation. Despite dramatically different sources of carbon and reducing power, nearly the same level of botryococcene or squalene (∼5 mg oil/g-dry-weight [gDW]) was achieved in small-scale aerobic heterotrophic, anaerobic photoheterotrophic, and aerobic chemoautotrophic growth conditions. A glucose fed-batch bioreactor reached 40 mg botryococcene/L (∼12 mg/gDW), while autotrophic bioreactor performance with CO2 , H2 , and O2 reached 110 mg/L (16.7 mg/gDW) during batch and 60 mg/L (23 mg/gDW) during continuous operation at a dilution rate corresponding to about 10% of μ(max). Batch and continuous autotrophic specific productivity was found to reach 0.5 and 0.32 mg triterpene/g DW/h, comparable to prior reports for terpene production driven by heterotrophic growth conditions. This demonstrates the feasibility of alternative feedstocks and trophic modes to provide comparable routes to biochemicals that do not rely on sugar.
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Affiliation(s)
- Nymul E Khan
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - S Eric Nybo
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, 40536
| | - Joe Chappell
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, 40536
| | - Wayne R Curtis
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802.
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27
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Nybo SE, Khan NE, Woolston BM, Curtis WR. Metabolic engineering in chemolithoautotrophic hosts for the production of fuels and chemicals. Metab Eng 2015; 30:105-120. [PMID: 25959019 DOI: 10.1016/j.ymben.2015.04.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/06/2015] [Accepted: 04/29/2015] [Indexed: 12/19/2022]
Abstract
The ability of autotrophic organisms to fix CO2 presents an opportunity to utilize this 'greenhouse gas' as an inexpensive substrate for biochemical production. Unlike conventional heterotrophic microorganisms that consume carbohydrates and amino acids, prokaryotic chemolithoautotrophs have evolved the capacity to utilize reduced chemical compounds to fix CO2 and drive metabolic processes. The use of chemolithoautotrophic hosts as production platforms has been renewed by the prospect of metabolically engineered commodity chemicals and fuels. Efforts such as the ARPA-E electrofuels program highlight both the potential and obstacles that chemolithoautotrophic biosynthetic platforms provide. This review surveys the numerous advances that have been made in chemolithoautotrophic metabolic engineering with a focus on hydrogen oxidizing bacteria such as the model chemolithoautotrophic organism (Ralstonia), the purple photosynthetic bacteria (Rhodobacter), and anaerobic acetogens. Two alternative strategies of microbial chassis development are considered: (1) introducing or enhancing autotrophic capabilities (carbon fixation, hydrogen utilization) in model heterotrophic organisms, or (2) improving tools for pathway engineering (transformation methods, promoters, vectors etc.) in native autotrophic organisms. Unique characteristics of autotrophic growth as they relate to bioreactor design and process development are also discussed in the context of challenges and opportunities for genetic manipulation of organisms as production platforms.
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Affiliation(s)
- S Eric Nybo
- Department of Pharmaceutical Sciences, College of Pharmacy, Ferris State University, Big Rapids, MI, United States
| | - Nymul E Khan
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, United States
| | - Benjamin M Woolston
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Wayne R Curtis
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, United States.
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28
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Lin Z, Cui X, Zhao C, Yang S, Imhoff JF. Pigments accumulation via light and oxygen in Rhodobacter capsulatus strain XJ-1 isolated from saline soil. J Basic Microbiol 2013; 54:828-34. [PMID: 23686461 DOI: 10.1002/jobm.201200565] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 02/17/2013] [Indexed: 11/11/2022]
Abstract
A Rhodobacter capsulatus strain, designated XJ-1, isolated from saline soil, accumulated almost only one kind of bacteriochlorophyll a anaerobically in the light, aerobically in the light and dark, and the relative contents of the bacteriochlorophyll a were 44.61, 74.89, and 77.53% of the total pigments, respectively. A new purple pigment appeared only in aerobic-light grown cells, exhibited absorption maxima at 355, 389, 520, 621, and 755 nm, especially distinctly unusual peak at 621 nm, whereas vanished in anaerobic-light and in aerobic-dark culture. Spheroidene and OH-spheroidene predominated in anaerobic phototrophic cultures. Spheroidenone was the sole carotenoid when exposed to both light and oxygen. The second keto-carotenoids, OH-spheroidenone, presented only in aerobic-dark culture in addition to spheroidenone. Strain XJ-1 would be a good model organism for the further illustration of the regulation of bacteriochlorophyll biosynthesis gene expression in response to unique habitat.
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Affiliation(s)
- Zhihua Lin
- College of Life Science, Shanxi University, Taiyuan, China
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Phylogeny and photoheterotrophy in the acidophilic phototrophic purple bacterium Rhodoblastus acidophilus. Arch Microbiol 2012; 194:567-74. [DOI: 10.1007/s00203-012-0790-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 01/03/2012] [Accepted: 01/05/2012] [Indexed: 10/14/2022]
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Fogg PC, Hynes AP, Digby E, Lang AS, Beatty JT. Characterization of a newly discovered Mu-like bacteriophage, RcapMu, in Rhodobacter capsulatus strain SB1003. Virology 2011; 421:211-21. [DOI: 10.1016/j.virol.2011.09.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 08/25/2011] [Accepted: 09/28/2011] [Indexed: 10/16/2022]
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Integrative Control of Carbon, Nitrogen, Hydrogen, and Sulfur Metabolism: The Central Role of the Calvin–Benson–Bassham Cycle. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010. [DOI: 10.1007/978-1-4419-1528-3_15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Bauer CE, Setterdahl A, Wu J, Robinson BR. Regulation of Gene Expression in Response to Oxygen Tension. THE PURPLE PHOTOTROPHIC BACTERIA 2009. [DOI: 10.1007/978-1-4020-8815-5_35] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Madigan MT, Jung DO. An Overview of Purple Bacteria: Systematics, Physiology, and Habitats. THE PURPLE PHOTOTROPHIC BACTERIA 2009. [DOI: 10.1007/978-1-4020-8815-5_1] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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35
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RegB/RegA, A Global Redox-Responding Two-Component System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 631:131-48. [DOI: 10.1007/978-0-387-78885-2_9] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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36
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Zeng X, Roh JH, Callister SJ, Tavano CL, Donohue TJ, Lipton MS, Kaplan S. Proteomic characterization of the Rhodobacter sphaeroides 2.4.1 photosynthetic membrane: identification of new proteins. J Bacteriol 2007; 189:7464-74. [PMID: 17704227 PMCID: PMC2168454 DOI: 10.1128/jb.00946-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Rhodobacter sphaeroides intracytoplasmic membrane (ICM) is an inducible membrane that is dedicated to the major events of bacterial photosynthesis, including harvesting light energy, separating primary charges, and transporting electrons. In this study, multichromatographic methods coupled with Fourier transform ion cyclotron resonance mass spectrometry, combined with subcellular fractionation, was used to test the hypothesis that the photosynthetic membrane of R. sphaeroides 2.4.1 contains a significant number of heretofore unidentified proteins in addition to the integral membrane pigment-protein complexes, including light-harvesting complexes 1 and 2, the photochemical reaction center, and the cytochrome bc(1) complex described previously. Purified ICM vesicles are shown to be enriched in several abundant, newly identified membrane proteins, including a protein of unknown function (AffyChip designation RSP1760) and a possible alkane hydroxylase (RSP1467). When the genes encoding these proteins are mutated, specific photosynthetic phenotypes are noted, illustrating the potential new insights into solar energy utilization to be gained by this proteomic blueprint of the ICM. In addition, proteins necessary for other cellular functions, such as ATP synthesis, respiration, solute transport, protein translocation, and other physiological processes, were also identified to be in association with the ICM. This study is the first to provide a more global view of the protein composition of a photosynthetic membrane from any source. This protein blueprint also provides insights into potential mechanisms for the assembly of the pigment-protein complexes of the photosynthetic apparatus, the formation of the lipid bilayer that houses these integral membrane proteins, and the possible functional interactions of ICM proteins with activities that reside in domains outside this specialized bioenergetic membrane.
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Affiliation(s)
- Xiaohua Zeng
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston TX, 77030, USA
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Sirijovski N, Mamedov F, Olsson U, Styring S, Hansson M. Rhodobacter capsulatus magnesium chelatase subunit BchH contains an oxygen sensitive iron-sulfur cluster. Arch Microbiol 2007; 188:599-608. [PMID: 17639347 DOI: 10.1007/s00203-007-0282-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 06/01/2007] [Accepted: 06/16/2007] [Indexed: 11/29/2022]
Abstract
Magnesium chelatase is the first unique enzyme of the bacteriochlorophyll biosynthetic pathway. It consists of three subunits (BchI, BchD, and BchH). Amino acid sequence analysis of the Rhodobacter capsulatus BchH revealed a novel cysteine motif (393CX2CX3CX14C) that was found in only six other proteobacteria (CX2CX3CX11-14C). The cysteine motif is likely to coordinate an unprecedented [Fe-S] cluster. Purified BchH demonstrated absorbance in the 460 nm region. This absorbance was abolished in BchH proteins with alanine substitutions at positions Cys396 and Cys414. These modified proteins were also EPR silent. In contrast, wild type BchH protein in the reduced state showed EPR signals resembling those of a [4Fe-4S] cluster with rhombic symmetry and g values at 1.90, 1.93, and 2.09, superimposed with a [3Fe-4S] cluster centered at g = 2.02. The [3Fe-4S] signal was observed independently of the [4Fe-4S] signal under oxidizing conditions. Mg-chelatase activity assays showed that the cluster is not catalytic. We suggest that the [4Fe-4S] and [3Fe-4S] signals originate from a single coordination site on the monomeric BchH protein and that the [4Fe-4S] cluster is sensitive to oxidation. It is speculated that the cluster participates in the switching between aerobic and anaerobic life of the proteobacteria.
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Affiliation(s)
- Nick Sirijovski
- Department of Biochemistry, Center for Molecular Protein Science, Lund University, PO Box 124, 221 00 Lund, Sweden.
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Hamblin MJ, Shaw JG, Curson JP, Kelly DJ. Mutagenesis, cloning and complementation analysis of C4-dicarboxylate transport genes fromRhodobacter capsulatus. Mol Microbiol 2006; 4:1567-1574. [DOI: 10.1111/j.1365-2958.1990.tb02068.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Yoshida S, Inui M, Yukawa H, Kanao T, Tomizawa KI, Atomi H, Imanaka T. Phototrophic growth of a Rubisco-deficient mesophilic purple nonsulfur bacterium harboring a Type III Rubisco from a hyperthermophilic archaeon. J Biotechnol 2006; 124:532-44. [PMID: 16530868 DOI: 10.1016/j.jbiotec.2006.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2005] [Revised: 01/24/2006] [Accepted: 02/01/2006] [Indexed: 10/24/2022]
Abstract
The hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1 harbors a structurally novel, Type III Rubisco (Rbc(Tk)). In terms of protein engineering of Rubiscos, the enzyme may provide an alternative target to the conventional Type I and Type II enzymes. With a future aim to improve the catalytic properties of Rbc(Tk), here we examined whether or not the enzyme could support growth of a mesophilic organism dependent on CO2 fixation. Via double-crossover homologous recombination, we first deleted three Rubisco genes present on the chromosome of the photosynthetic mesophile Rhodopseudomonas palustris No. 7. The mutant strain (delta3) could neither grow under photoautotrophic nor photoheterotrophic conditions. We introduced the rbc(Tk) gene into strain delta3 either on a plasmid, or by integrating the gene onto the chromosome. The two transformant strains harboring rbc(Tk) displayed growth under photoautotrophic and photoheterotrophic conditions, both dependent on CO2 fixation. Specific growth rates and Rubisco activity levels were compared under photoheterotrophic conditions among the two transformants and the wild-type strain. We observed that the levels of Rubisco activity in the respective cell-free extracts correlated well with the specific growth rates. Immunoprecipitation experiments revealed that Rubisco activity detected in the transformants was derived solely from Rbc(Tk). These results demonstrated that the Type III Rbc(Tk) from a hyperthermophile could support CO2 fixation in a mesophilic organism, and that the specific growth rate of the transformant can be used as a convenient parameter for selection of engineered proteins with improved Rubisco activity.
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Affiliation(s)
- Shosuke Yoshida
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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Elsen S, Swem LR, Swem DL, Bauer CE. RegB/RegA, a highly conserved redox-responding global two-component regulatory system. Microbiol Mol Biol Rev 2004; 68:263-79. [PMID: 15187184 PMCID: PMC419920 DOI: 10.1128/mmbr.68.2.263-279.2004] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Reg regulon from Rhodobacter capsulatus and Rhodobacter sphaeroides encodes proteins involved in numerous energy-generating and energy-utilizing processes such as photosynthesis, carbon fixation, nitrogen fixation, hydrogen utilization, aerobic and anaerobic respiration, denitrification, electron transport, and aerotaxis. The redox signal that is detected by the membrane-bound sensor kinase, RegB, appears to originate from the aerobic respiratory chain, given that mutations in cytochrome c oxidase result in constitutive RegB autophosphorylation. Regulation of RegB autophosphorylation also involves a redox-active cysteine that is present in the cytosolic region of RegB. Both phosphorylated and unphosphorylated forms of the cognate response regulator RegA are capable of activating or repressing a variety of genes in the regulon. Highly conserved homologues of RegB and RegA have been found in a wide number of photosynthetic and nonphotosynthetic bacteria, with evidence suggesting that RegB/RegA plays a fundamental role in the transcription of redox-regulated genes in many bacterial species.
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Affiliation(s)
- Sylvie Elsen
- Laboratoire de Biochimie et de Biophysique des Systèmes Intégrés (UMR 5092 CNRS-CEA-UJF), Grenoble, France
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Novak RT, Gritzer RF, Leadbetter ER, Godchaux W. Phototrophic utilization of taurine by the purple nonsulfur bacteria Rhodopseudomonas palustris and Rhodobacter sphaeroides. Microbiology (Reading) 2004; 150:1881-1891. [PMID: 15184574 DOI: 10.1099/mic.0.27023-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Taurine metabolism by two phototrophically grown purple nonsulfur bacteria enrichment isolates has been examined.Rhodopseudomonas palustris(strain Tau1) grows with taurine as a sole electron donor, sulfur and nitrogen source during photoautotrophic growth.Rhodobacter sphaeroides(strain Tau3) grows on the compound as sole electron donor, sulfur and nitrogen source, and partial carbon source, in the presence of CO2during photoheterotrophic growth. Both organisms utilize an inducible taurine–pyruvate aminotransferase and a sulfoacetaldehyde acetyltransferase. The products of this metabolism are bisulfite and acetyl phosphate. Bisulfite ultimately was oxidized to sulfate, but this was not an adequate source of electrons for photometabolism. Experiments using either [U-14C]taurine or14CO2demonstrated thatRb. sphaeroidesTau3 assimilated the carbon from approximately equimolar amounts of taurine and exogenous CO2. The taurine-carbon assimilation was not diminished by excess non-radioactive bicarbonate. Malate synthase (but not isocitrate lyase) was induced in these taurine-grown cells. It is concluded that assimilation of taurine carbon occurs through an intermediate other than CO2. Similar labelling experiments withRp. palustrisTau1 determined that taurine is utilized only as an electron donor for the reduction of CO2, which contributes all the cell carbon. Photoautotrophic metabolism was confirmed in this organism by the absence of either malate synthase or isocitrate lyase in taurine+CO2-grown cells. Culture collection strains of these two bacteria did not utilize taurine in these fashions.
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Affiliation(s)
- Ryan T Novak
- U-2131 Beach Hall, University of Connecticut, Storrs, CT 06269, USA
| | - Rachel F Gritzer
- U-2131 Beach Hall, University of Connecticut, Storrs, CT 06269, USA
| | | | - Walter Godchaux
- U-2131 Beach Hall, University of Connecticut, Storrs, CT 06269, USA
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Kappler U, Huston WM, McEwan AG. Control of dimethylsulfoxide reductase expression in Rhodobacter capsulatus: the role of carbon metabolites and the response regulators DorR and RegA. MICROBIOLOGY (READING, ENGLAND) 2002; 148:605-614. [PMID: 11832523 DOI: 10.1099/00221287-148-2-605] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Regulation of the expression of dimethylsulfoxide (DMSO) reductase was investigated in the purple phototrophic bacterium Rhodobacter capsulatus. Under phototrophic, anaerobic conditions with malate as carbon source, DMSO caused an approximately 150-fold induction of DMSO reductase activity. The response regulator DorR was required for DMSO-dependent induction and also appeared to slightly repress DMSO reductase expression in the absence of substrate. Likewise, when pyruvate replaced malate as carbon source there was an induction of DMSO reductase activity in cells grown at low light intensity (16 W m(-2)) and again this induction was dependent on DorR. The level of DMSO reductase activity in aerobically grown cells was elevated when pyruvate replaced malate as carbon source. One possible explanation for this is that acetyl phosphate, produced from pyruvate, may activate expression of DMSO reductase by direct phosphorylation of DorR, leading to low levels of induction of dor gene expression in the absence of DMSO. A mutant lacking the global response regulator of photosynthesis gene expression, RegA, exhibited high levels of DMSO reductase in the absence of DMSO, when grown phototrophically with malate as carbon source. This suggests that phosphorylated RegA acts as a repressor of dor operon expression under these conditions. It has been proposed elsewhere that RegA-dependent expression is negatively regulated by the cytochrome cbb3 oxidase. A cco mutant lacking cytochrome cbb3 exhibited significantly higher levels of phi[dorA::lacZ] activity in the presence of DMSO compared to wild-type cells and this is consistent with the above model. Pyruvate restored DMSO reductase expression in the regA mutant to the same pattern as found in wild-type cells. These data suggest that R. capsulatus contains a regulator of DMSO respiration that is distinct from DorR and RegA, is activated in the presence of pyruvate, and acts as a negative regulator of DMSO reductase expression.
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Affiliation(s)
- Ulrike Kappler
- Department of Microbiology & Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Qld 4072, Australia1
| | - Wilhelmina M Huston
- Department of Microbiology & Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Qld 4072, Australia1
| | - Alastair G McEwan
- Department of Microbiology & Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Qld 4072, Australia1
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Tichi MA, Meijer WG, Tabita FR. Complex I and its involvement in redox homeostasis and carbon and nitrogen metabolism in Rhodobacter capsulatus. J Bacteriol 2001; 183:7285-94. [PMID: 11717288 PMCID: PMC95578 DOI: 10.1128/jb.183.24.7285-7294.2001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A transposon mutant of Rhodobacter capsulatus, strain Mal7, that was incapable of photoautotrophic and chemoautotrophic growth and could not grow photoheterotrophically in the absence of an exogenous electron acceptor was isolated. The phenotype of strain Mal7 suggested that the mutation was in some gene(s) not previously shown to be involved in CO(2) fixation control. The site of transposition in strain Mal7 was identified and shown to be in the gene nuoF, which encodes one of the 14 subunits for NADH ubiquinone-oxidoreductase, or complex I. To confirm the role of complex I and nuoF for CO(2)-dependent growth, a site-directed nuoF mutant was constructed (strain SBC1) in wild-type strain SB1003. The complex I-deficient strains Mal7 and SBC1 exhibited identical phenotypes, and the pattern of CO(2) fixation control through the Calvin-Benson-Bassham pathway was the same for both strains. It addition, it was shown that electron transport through complex I led to differential control of the two major cbb operons of this organism. Complex I was further shown to be linked to the control of nitrogen metabolism during anaerobic photosynthetic growth of R. capsulatus.
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Affiliation(s)
- M A Tichi
- Department of Microbiology and the Plant Molecular Biology/Biotechnology Program, The Ohio State University, Columbus, Ohio 43210-1292, USA
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McEwan AG, George CL, Ferguson SJ, Jackson J. A nitrate reductase activity inRhodopseudomonas capsulatalinked to electron transfer and generation of a membrane potential. FEBS Lett 2001. [DOI: 10.1016/0014-5793(82)80751-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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45
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Tichi MA, Tabita FR. Interactive control of Rhodobacter capsulatus redox-balancing systems during phototrophic metabolism. J Bacteriol 2001; 183:6344-54. [PMID: 11591679 PMCID: PMC100130 DOI: 10.1128/jb.183.21.6344-6354.2001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In nonsulfur purple bacteria, redox homeostasis is achieved by the coordinate control of various oxidation-reduction balancing mechanisms during phototrophic anaerobic respiration. In this study, the ability of Rhodobacter capsulatus to maintain a balanced intracellular oxidation-reduction potential was considered; in addition, interrelationships between the control of known redox-balancing systems, the Calvin-Benson-Bassham, dinitrogenase and dimethyl sulfoxide reductase systems, were probed in strains grown under both photoheterotrophic and photoautotrophic growth conditions. By using cbb(I) (cbb form I operon)-, cbb(II)-, nifH-, and dorC-reporter gene fusions, it was demonstrated that each redox-balancing system responds to specific metabolic circumstances under phototrophic growth conditions. In specific mutant strains of R. capsulatus, expression of both the Calvin-Benson-Bassham and dinitrogenase systems was influenced by dimethyl sulfoxide respiration. Under photoheterotrophic growth conditions, coordinate control of redox-balancing systems was further manifested in ribulose 1,5-bisphosphate carboxylase/oxygenase and phosphoribulokinase deletion strains. These findings demonstrated the existence of interactive control mechanisms that govern the diverse means by which R. capsulatus maintains redox poise during photoheterotrophic and photoautotrophic growth.
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Affiliation(s)
- M A Tichi
- Department of Microbiology and Plant Molecular Biology/Biotechnology Program, The Ohio State University, Columbus, Ohio 43210-1292, USA
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46
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Pantazopoulous PE, Madigan MT. Primary alcohols and di-alcohols as growth substrates for the purple nonsulfur bacteriumRhodobacter capsulatus. Can J Microbiol 2000. [DOI: 10.1139/w00-104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Growth experiments were performed with the purple nonsulfur bacterium Rhodobacter capsulatus to test its ability to use aliphatic, methyl-substituted, and unsaturated alcohols, as well as di-alcohols, as carbon sources for growth. Both phototrophic and chemotrophic growth was observed on a wide variety of such alcohols. By contrast, secondary or tertiary alcohols, or primary alcohols containing an ethyl or propyl substituent, did not support growth. In addition, preculture history and serial subculturing were found to be important factors for obtaining reliable growth of R. capsulatus on alcohols. Collectively, these results suggest that the carbon nutritional diversity of Rhodobacter capsulatus is even greater than previously suspected and that besides metabolizing organic acids and fatty acids in nature, this species may also be a major consumer of alcohols.Key words: purple nonsulfur bacteria, Rhodobacter capsulatus, alcohol metabolism, primary alcohols, di-alcohols.
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Elsen S, Dischert W, Colbeau A, Bauer CE. Expression of uptake hydrogenase and molybdenum nitrogenase in Rhodobacter capsulatus is coregulated by the RegB-RegA two-component regulatory system. J Bacteriol 2000; 182:2831-7. [PMID: 10781552 PMCID: PMC101992 DOI: 10.1128/jb.182.10.2831-2837.2000] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purple photosynthetic bacteria are capable of generating cellular energy from several sources, including photosynthesis, respiration, and H(2) oxidation. Under nutrient-limiting conditions, cellular energy can be used to assimilate carbon and nitrogen. This study provides the first evidence of a molecular link for the coregulation of nitrogenase and hydrogenase biosynthesis in an anoxygenic photosynthetic bacterium. We demonstrated that molybdenum nitrogenase biosynthesis is under the control of the RegB-RegA two-component regulatory system in Rhodobacter capsulatus. Footprint analyses and in vivo transcription studies showed that RegA indirectly activates nitrogenase synthesis by binding to and activating the expression of nifA2, which encodes one of the two functional copies of the nif-specific transcriptional activator, NifA. Expression of nifA2 but not nifA1 is reduced in the reg mutants up to eightfold under derepressing conditions and is also reduced under repressing conditions. Thus, although NtrC is absolutely required for nifA2 expression, RegA acts as a coactivator of nifA2. We also demonstrated that in reg mutants, [NiFe]hydrogenase synthesis and activity are increased up to sixfold. RegA binds to the promoter of the hydrogenase gene operon and therefore directly represses its expression. Thus, the RegB-RegA system controls such diverse processes as energy-generating photosynthesis and H(2) oxidation, as well as the energy-demanding processes of N(2) fixation and CO(2) assimilation.
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Affiliation(s)
- S Elsen
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
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Dubbs JM, Tabita FR. Two functionally distinct regions upstream of the cbbI operon of Rhodobacter sphaeroides regulate gene expression. J Bacteriol 1998; 180:4903-11. [PMID: 9733694 PMCID: PMC107516 DOI: 10.1128/jb.180.18.4903-4911.1998] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/1997] [Accepted: 07/21/1998] [Indexed: 11/20/2022] Open
Abstract
A number of cbbFI::lacZ translational fusion plasmids containing various lengths of sequence 5' to the form I (cbbI) Calvin-Benson-Bassham cycle operon (cbbFIcbbPIcbbAIcbbLIcbbSI) of Rhodobacter sphaeroides were constructed. Expression of beta-galactosidase was monitored under a variety of growth conditions. It was found that 103 bp of sequence upstream of the cbbFI transcription start was sufficient to confer low levels of regulated cbbI promoter expression; this activity was dependent on the presence of an intact cbbR gene. Additionally, R. sphaeroides CbbR was shown to bind to the region between 9 and 100 bp 5' to the cbbFI transcription start. Inclusion of an additional upstream sequence, from 280 to 636 bp 5' to cbbFI, resulted in a significant increase in regulated cbbI promoter expression under all growth conditions tested. A 50-bp region responsible for the majority of this increase occurs between 280 and 330 bp 5' to cbbFI. The additional 306 bp of upstream sequence from 330 to 636 bp also appears to play a positive regulatory role. A 4-bp deletion 281 to 284 bp 5' to cbbFI significantly reduced cbbI expression while the proper regulatory pattern was retained. These studies provide evidence for the presence of two functionally distinct regions of the cbbI promoter, with the distal domain providing significant regulated promoter activity that adheres to the normal pattern of expression.
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Affiliation(s)
- J M Dubbs
- Department of Microbiology and the Plant Molecular Biology/Biotechnology Program, The Ohio State University, Columbus, Ohio 43210-1292, USA
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Abstract
The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynthetically under anaerobic conditions. Aerobic anoxygenic phototrophic bacteria are classified in two marine (Erythrobacter and Roseobacter) and six freshwater (Acidiphilium, Erythromicrobium, Erythromonas, Porphyrobacter, Roseococcus, and Sandaracinobacter) genera, which phylogenetically belong to the alpha-1, alpha-3, and alpha-4 subclasses of the class Proteobacteria. Despite this phylogenetic information, the evolution and ancestry of their photosynthetic properties are unclear. We discuss several current proposals for the evolutionary origin of aerobic phototrophic bacteria. The closest phylogenetic relatives of aerobic phototrophic bacteria include facultatively anaerobic purple nonsulfur phototrophic bacteria. Since these two bacterial groups share many properties, yet have significant differences, we compare and contrast their physiology, with an emphasis on morphology and photosynthetic and other metabolic processes.
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Affiliation(s)
- V V Yurkov
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, Canada V6T 1Z3.
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Paoli GC, Vichivanives P, Tabita FR. Physiological control and regulation of the Rhodobacter capsulatus cbb operons. J Bacteriol 1998; 180:4258-69. [PMID: 9696777 PMCID: PMC107425 DOI: 10.1128/jb.180.16.4258-4269.1998] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/1998] [Accepted: 06/03/1998] [Indexed: 11/20/2022] Open
Abstract
The genes encoding enzymes of the Calvin-Benson-Bassham (CBB) reductive pentose phosphate pathway in Rhodobacter capsulatus are organized in at least two operons, each preceded by a separate cbbR gene, encoding potential LysR-type transcriptional activators. As a prelude to studies of cbb gene regulation in R. capsulatus, the nucleotide sequence of a 4,537-bp region, which included cbbRII, was determined. This region contained the following open reading frames: a partial pgm gene (encoding phosphoglucomutase) and a complete qor gene (encoding NADPH:quinone oxidoreductase), followed by cbbRII, cbbF (encoding fructose 1,6-bisphosphatase), cbbP (encoding phosphoribulokinase), and part of cbbT (encoding transketolase). Physiological control of the CBB pathway and regulation of the R. capsulatus cbb genes were studied by using a combination of mutant strains and promoter fusion constructs. Characterization of mutant strains revealed that either form I or form II ribulose 1, 5-bisphosphate carboxylase/oxygenase (RubisCO), encoded by the cbbLS and cbbM genes, respectively, could support photoheterotrophic and autotrophic growth. A strain with disruptions in both cbbL and cbbM could not grow autotrophically and grew photoheterotrophically only when dimethyl sulfoxide was added to the culture medium. Disruption of cbbP resulted in a strain that did not synthesize form II RubisCO and had a phenotype similar to that observed in the RubisCO-minus strain, suggesting that there is only one cbbP gene in R. capsulatus and that this gene is cotranscribed with cbbM. Analysis of RubisCO activity and synthesis in strains with disruptions in either cbbRI or cbbRII, and beta-galactosidase determinations from wild-type and mutant strains containing cbbIp- and cbbIIp-lacZ fusion constructs, indicated that the cbbI and cbbII operons of R. capsulatus are within separate CbbR regulons.
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Affiliation(s)
- G C Paoli
- Department of Microbiology and Plant Molecular Biology/Biotechnology Program, The Ohio State University, Columbus, Ohio 43210-1292, USA
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