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Moravcová M, Siatka T, Krčmová LK, Matoušová K, Mladěnka P. Biological properties of vitamin B 12. Nutr Res Rev 2024:1-33. [PMID: 39376196 DOI: 10.1017/s0954422424000210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
Vitamin B12, cobalamin, is indispensable for humans owing to its participation in two biochemical reactions: the conversion of l-methylmalonyl coenzyme A to succinyl coenzyme A, and the formation of methionine by methylation of homocysteine. Eukaryotes, encompassing plants, fungi, animals and humans, do not synthesise vitamin B12, in contrast to prokaryotes. Humans must consume it in their diet. The most important sources include meat, milk and dairy products, fish, shellfish and eggs. Due to this, vegetarians are at risk to develop a vitamin B12 deficiency and it is recommended that they consume fortified food. Vitamin B12 behaves differently to most vitamins of the B complex in several aspects, e.g. it is more stable, has a very specific mechanism of absorption and is stored in large amounts in the organism. This review summarises all its biological aspects (including its structure and natural sources as well as its stability in food, pharmacokinetics and physiological function) as well as causes, symptoms, diagnosis (with a summary of analytical methods for its measurement), prevention and treatment of its deficiency, and its pharmacological use and potential toxicity.
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Affiliation(s)
- Monika Moravcová
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic
| | - Tomáš Siatka
- Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic
| | - Lenka Kujovská Krčmová
- Department of Clinical Biochemistry and Diagnostics, University Hospital Hradec Králové, Hradec Králové, Czech Republic
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic
| | - Kateřina Matoušová
- Department of Clinical Biochemistry and Diagnostics, University Hospital Hradec Králové, Hradec Králové, Czech Republic
| | - Přemysl Mladěnka
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic
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2
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Beauvais M, Schatt P, Montiel L, Logares R, Galand PE, Bouget FY. Functional redundancy of seasonal vitamin B 12 biosynthesis pathways in coastal marine microbial communities. Environ Microbiol 2023; 25:3753-3770. [PMID: 38031968 DOI: 10.1111/1462-2920.16545] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/15/2023] [Indexed: 12/01/2023]
Abstract
Vitamin B12 (cobalamin) is a major cofactor required by most marine microbes, but only produced by a few prokaryotes in the ocean, which is globally B12 -depleted. Despite the ecological importance of B12 , the seasonality of B12 metabolisms and the organisms involved in its synthesis in the ocean remain poorly known. Here we use metagenomics to assess the monthly dynamics of B12 -related pathways and the functional diversity of associated microbial communities in the coastal NW Mediterranean Sea over 7 years. We show that genes related to potential B12 metabolisms were characterized by an annual succession of different organisms carrying distinct production pathways. During the most productive winter months, archaea (Nitrosopumilus and Nitrosopelagicus) were the main contributors to B12 synthesis potential through the anaerobic pathway (cbi genes). In turn, Alphaproteobacteria (HIMB11, UBA8309, Puniceispirillum) contributed to B12 synthesis potential in spring and summer through the aerobic pathway (cob genes). Cyanobacteria could produce pseudo-cobalamin from spring to autumn. Finally, we show that during years with environmental perturbations, the organisms usually carrying B12 synthesis genes were replaced by others having the same gene, thus maintaining the potential for B12 production. Such ecological insurance could contribute to the long-term functional resilience of marine microbial communities exposed to contrasting inter-annual environmental conditions.
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Affiliation(s)
- Maxime Beauvais
- Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique de Banyuls, Banyuls sur Mer, France
| | - Philippe Schatt
- Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique de Banyuls, Banyuls sur Mer, France
| | - Lidia Montiel
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (ICM-CSIC), Barcelona, Spain
| | - Ramiro Logares
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (ICM-CSIC), Barcelona, Spain
| | - Pierre E Galand
- Sorbonne Université, CNRS, Laboratoire d'Écogéochimie des Environnements Benthiques (LECOB), Observatoire Océanologique de Banyuls, Banyuls sur Mer, France
| | - François-Yves Bouget
- Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique de Banyuls, Banyuls sur Mer, France
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3
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Mars Brisbin M, Mitarai S, Saito MA, Alexander H. Microbiomes of bloom-forming Phaeocystis algae are stable and consistently recruited, with both symbiotic and opportunistic modes. THE ISME JOURNAL 2022; 16:2255-2264. [PMID: 35764675 PMCID: PMC9381791 DOI: 10.1038/s41396-022-01263-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/11/2022] [Accepted: 05/31/2022] [Indexed: 05/29/2023]
Abstract
Phaeocystis is a cosmopolitan, bloom-forming phytoplankton genus that contributes significantly to global carbon and sulfur cycles. During blooms, Phaeocystis species produce large carbon-rich colonies, creating a unique interface for bacterial interactions. While bacteria are known to interact with phytoplankton-e.g., they promote growth by producing phytohormones and vitamins-such interactions have not been shown for Phaeocystis. Therefore, we investigated the composition and function of P. globosa microbiomes. Specifically, we tested whether microbiome compositions are consistent across individual colonies from four P. globosa strains, whether similar microbiomes are re-recruited after antibiotic treatment, and how microbiomes affect P. globosa growth under limiting conditions. Results illuminated a core colonial P. globosa microbiome-including bacteria from the orders Alteromonadales, Burkholderiales, and Rhizobiales-that was re-recruited after microbiome disruption. Consistent microbiome composition and recruitment is indicative that P. globosa microbiomes are stable-state systems undergoing deterministic community assembly and suggests there are specific, beneficial interactions between Phaeocystis and bacteria. Growth experiments with axenic and nonaxenic cultures demonstrated that microbiomes allowed continued growth when B-vitamins were withheld, but that microbiomes accelerated culture collapse when nitrogen was withheld. In sum, this study reveals symbiotic and opportunistic interactions between Phaeocystis colonies and microbiome bacteria that could influence large-scale phytoplankton bloom dynamics and biogeochemical cycles.
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Affiliation(s)
- Margaret Mars Brisbin
- Marine Biophysics Unit, Okinawa Institute of Science and Technology, Okinawa, Japan.
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - Satoshi Mitarai
- Marine Biophysics Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Mak A Saito
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Harriet Alexander
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
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4
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Ewald JM, Schnoor JL, Mattes TE. Combined read- and assembly-based metagenomics to reconstruct a Dehalococcoides mccartyi genome from PCB-contaminated sediments and evaluate functional differences among organohalide-respiring consortia in the presence of different halogenated contaminants. FEMS Microbiol Ecol 2022; 98:6602352. [PMID: 35665806 DOI: 10.1093/femsec/fiac067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/27/2022] [Accepted: 05/31/2022] [Indexed: 11/12/2022] Open
Abstract
Microbial communities that support respiration of halogenated organic contaminants by Dehalococcoides sp. facilitate full-scale bioremediation of chlorinated ethenes and demonstrate the potential to aid in bioremediation of halogenated aromatics like polychlorinated biphenyls (PCBs). However, it remains unclear if Dehalococcoides-containing microbial community dynamics observed in sediment-free systems quantitatively resemble that of sediment environments. To evaluate that possibility we assembled, annotated, and analyzed a Dehalococcoides sp. metagenome-assembled genome (MAG) from PCB-contaminated sediments. Phylogenetic analysis of reductive dehalogenase gene (rdhA) sequences within the MAG revealed that pcbA1 and pcbA4/5-like rdhA were absent, while several candidate PCB dehalogenase genes and potentially novel rdhA sequences were identified. Using a compositional comparative metagenomics approach, we quantified Dehalococcoides-containing microbial community structure shifts in response to halogenated organics and the presence of sediments. Functional level analysis revealed significantly greater abundances of genes associated with cobamide remodeling and horizontal gene transfer in tetrachloroethene-fed cultures as compared to halogenated aromatic-exposed consortia with or without sediments, despite little evidence of statistically significant differences in microbial community taxonomic structure. Our findings support the use of a generalizable comparative metagenomics workflow to evaluate Dehalococcoides-containing consortia in sediments and sediment-free environments to eludicate functions and microbial interactions that facilitate bioremediation of halogenated organic contaminants.
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Affiliation(s)
- Jessica M Ewald
- Department of Civil and Environmental Engineering, 4105 Seamans Center, University of Iowa, Iowa City, IA, 52242, USA
| | - Jerald L Schnoor
- Department of Civil and Environmental Engineering, 4105 Seamans Center, University of Iowa, Iowa City, IA, 52242, USA
| | - Timothy E Mattes
- Department of Civil and Environmental Engineering, 4105 Seamans Center, University of Iowa, Iowa City, IA, 52242, USA
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5
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Cordone A, D’Errico G, Magliulo M, Bolinesi F, Selci M, Basili M, de Marco R, Saggiomo M, Rivaro P, Giovannelli D, Mangoni O. Bacterioplankton Diversity and Distribution in Relation to Phytoplankton Community Structure in the Ross Sea Surface Waters. Front Microbiol 2022; 13:722900. [PMID: 35154048 PMCID: PMC8828583 DOI: 10.3389/fmicb.2022.722900] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/05/2022] [Indexed: 01/04/2023] Open
Abstract
Primary productivity in the Ross Sea region is characterized by intense phytoplankton blooms whose temporal and spatial distribution are driven by changes in environmental conditions as well as interactions with the bacterioplankton community. However, the number of studies reporting the simultaneous diversity of the phytoplankton and bacterioplankton in Antarctic waters are limited. Here, we report data on the bacterial diversity in relation to phytoplankton community structure in the surface waters of the Ross Sea during the Austral summer 2017. Our results show partially overlapping bacterioplankton communities between the stations located in the Terra Nova Bay (TNB) coastal waters and the Ross Sea Open Waters (RSOWs), with a dominance of members belonging to the bacterial phyla Bacteroidetes and Proteobacteria. In the TNB coastal area, microbial communities were characterized by a higher abundance of sequences related to heterotrophic bacterial genera such as Polaribacter spp., together with higher phytoplankton biomass and higher relative abundance of diatoms. On the contrary, the phytoplankton biomass in the RSOW were lower, with relatively higher contribution of haptophytes and a higher abundance of sequences related to oligotrophic and mixothrophic bacterial groups like the Oligotrophic Marine Gammaproteobacteria (OMG) group and SAR11. We show that the rate of diversity change between the two locations is influenced by both abiotic (salinity and the nitrogen to phosphorus ratio) and biotic (phytoplankton community structure) factors. Our data provide new insight into the coexistence of the bacterioplankton and phytoplankton in Antarctic waters, suggesting that specific rather than random interaction contribute to the organic matter cycling in the Southern Ocean.
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Affiliation(s)
- Angelina Cordone
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Giuseppe D’Errico
- Department of Life Sciences, DISVA, Polytechnic University of Marche, Ancona, Italy
| | - Maria Magliulo
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Francesco Bolinesi
- Department of Biology, University of Naples Federico II, Naples, Italy
- *Correspondence: Francesco Bolinesi,
| | - Matteo Selci
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Marco Basili
- National Research Council, Institute of Marine Biological Resources and Biotechnologies CNR-IRBIM, Ancona, Italy
| | - Rocco de Marco
- National Research Council, Institute of Marine Biological Resources and Biotechnologies CNR-IRBIM, Ancona, Italy
| | | | - Paola Rivaro
- Department of Chemistry and Industrial Chemistry, University of Genoa, Genoa, Italy
| | - Donato Giovannelli
- Department of Biology, University of Naples Federico II, Naples, Italy
- Department of Life Sciences, DISVA, Polytechnic University of Marche, Ancona, Italy
- National Research Council, Institute of Marine Biological Resources and Biotechnologies CNR-IRBIM, Ancona, Italy
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, United States
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Donato Giovannelli,
| | - Olga Mangoni
- Department of Biology, University of Naples Federico II, Naples, Italy
- Consorzio Nazionale Interuniversitario delle Scienze del Mare (CoNISMa), Rome, Italy
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6
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Ben Yahia M, Ben Yahia M. New insights in the physicochemical investigation of the vitamin B 12 nucleus using statistical physics treatment: interpretation of experiments and surface properties. RSC Adv 2020; 10:21724-21735. [PMID: 35516596 PMCID: PMC9054493 DOI: 10.1039/d0ra03077e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 05/14/2020] [Indexed: 11/24/2022] Open
Abstract
In this research paper, the equilibrium isotherms for the adsorption of cobalt(ii)nitrate and cobalt(ii)chloride on tetrakis(4-tolylphenyl)porphyrin (H2TTPP) were obtained at four temperatures for modeling analysis. The experimental data describing the adsorbed quantity of cobalt particles were measured using the quartz crystal microbalance (QCM) strategy. Then, statistical physics formalism was employed to interpret the complexation mechanism by applying the real gas law that contemplates the interaction between the adsorbate particles in the free state. Advanced models treated with the law of van der Waals were applied for the single and L.B.L adsorptions of Co2+ at various temperatures (288–318 K). The experimental adsorption data of CoCl2 on porphyrins were satisfactorily fitted with the monolayer equation, showing that the chlorine particles had no effect on the complexation system, while the nitrate particles were involved in the adsorption of Co(NO3)2 and contributed to the layer formation. The physicochemical parameters of statistical physics models were estimated and used to compare the complexation mechanisms of both adsorbates. The study of the cohesion pressure (a) and the co-volume (b) confirmed that cobalt chloride guaranteed more stability during the formation of the vitamin B12 nucleus. Deeper energetic analysis demonstrated that cobalt ions were complexed by ionic or covalent bonds in the case of cobalt chloride (complexation energy (–E1/2) varies from −48.2 to −50.3), while a physisorption process took place in the case of cobalt nitrate ((–E1) varies from −33.6 to −36.1), thus indicating that CoCl2–H2TTPP was the most stable complex. The statistical physics models were also used to investigate two thermodynamic functions that govern the adsorption mechanisms, namely, the configurational entropy and the Gibbs free enthalpy. Quartz Crystal Microbalance (QCM) setup for the measurement of adsorption isotherms of cobalt(ii)nitrate and cobalt(ii)chloride on tetrakis(4-tolylphenyl)porphyrin (H2TTPP).![]()
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Affiliation(s)
- Manel Ben Yahia
- Physics Department Rabigh College of Science and Arts, King Abdulaziz University Jeddah PO box 344 Rabigh 21911 Saudi Arabia
| | - Mohamed Ben Yahia
- Physics department, Laboratory of Quantum and Statistical Physics, LR18ES18, Faculty of Sciences of Monastir, University of Monastir Monastir 5000 Tunisia
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7
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Krayushkina D, Timmins-Schiffman E, Faux J, May DH, Riffle M, Harvey HR, Nunn BL. Growth phase proteomics of the heterotrophic marine bacterium Ruegeria pomeroyi. Sci Data 2019; 6:303. [PMID: 31796751 PMCID: PMC6890736 DOI: 10.1038/s41597-019-0308-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/07/2019] [Indexed: 11/14/2022] Open
Abstract
The heterotrophic marine bacterium, Ruegeria pomeroyi, was experimentally cultured under environmentally realistic carbon conditions and with a tracer-level addition of 13C-labeled leucine to track bacterial protein biosynthesis through growth phases. A combination of methods allowed observation of real-time bacterial protein production to understand metabolic priorities through the different growth phases. Over 2000 proteins were identified in each experimental culture from exponential and stationary growth phases. Within two hours of the 13C-labeled leucine addition, R. pomeroyi significantly assimilated the newly encountered substrate into new proteins. This dataset provides a fundamental baseline for understanding growth phase differences in molecular physiology of a cosmopolitan marine bacterium.
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Affiliation(s)
- Dasha Krayushkina
- University of Washington, Department of Psychiatry and Behavioral Sciences, Seattle, WA, 98195, USA
| | | | - Jessica Faux
- Old Dominion University, Department of Ocean, Earth & Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Damon H May
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA
| | - Michael Riffle
- University of Washington, Department of Biochemistry, Seattle, WA, 98195, USA
| | - H Rodger Harvey
- Old Dominion University, Department of Ocean, Earth & Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Brook L Nunn
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA.
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8
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Ma AT, Tyrell B, Beld J. Specificity of cobamide remodeling, uptake and utilization in Vibrio cholerae. Mol Microbiol 2019; 113:89-102. [PMID: 31609521 DOI: 10.1111/mmi.14402] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/11/2022]
Abstract
Cobamides are a group of compounds including vitamin B12 that can vary at the lower base position of the nucleotide loop. They are synthesized de novo by only a subset of prokaryotes, but some organisms encode partial biosynthesis pathways for converting one variant to another (remodeling) or completing biosynthesis from an intermediate (corrinoid salvaging). Here, we explore the cobamide specificity in Vibrio cholerae through examination of three natural variants representing major cobamide groups: commercially available cobalamin, and isolated pseudocobalamin and p-cresolylcobamide. We show that BtuB, the outer membrane corrinoid transporter, mediates the uptake of all three variants and the intermediate cobinamide. Our previous work suggested that V. cholerae could convert pseudocobalamin produced by cyanobacteria into cobalamin. In this work, cobamide specificity in V. cholerae is demonstrated by remodeling of pseudocobalamin and salvaging of cobinamide to produce cobalamin. Cobamide remodeling in V. cholerae is distinct from the canonical pathway requiring amidohydrolase CbiZ, and heterologous expression of V. cholerae CobS was sufficient for remodeling. Furthermore, function of V. cholerae cobamide-dependent methionine synthase MetH was robustly supported by cobalamin and p-cresolylcobamide, but not pseudocobalamin. Notably, the inability of V. cholerae to produce and utilize pseudocobalamin contrasts with enteric bacteria like Salmonella.
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Affiliation(s)
- Amy T Ma
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Breanna Tyrell
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Joris Beld
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
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9
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Metagenomic and chemical characterization of soil cobalamin production. ISME JOURNAL 2019; 14:53-66. [PMID: 31492962 PMCID: PMC6908642 DOI: 10.1038/s41396-019-0502-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 07/15/2019] [Accepted: 07/31/2019] [Indexed: 01/01/2023]
Abstract
Cobalamin (vitamin B12) is an essential enzyme cofactor for most branches of life. Despite the potential importance of this cofactor for soil microbial communities, the producers and consumers of cobalamin in terrestrial environments are still unknown. Here we provide the first metagenome-based assessment of soil cobalamin-producing bacteria and archaea, quantifying and classifying genes encoding proteins for cobalamin biosynthesis, transport, remodeling, and dependency in 155 soil metagenomes with profile hidden Markov models. We also measured several forms of cobalamin (CN-, Me-, OH-, Ado-B12) and the cobalamin lower ligand (5,6-dimethylbenzimidazole; DMB) in 40 diverse soil samples. Metagenomic analysis revealed that less than 10% of soil bacteria and archaea encode the genetic potential for de novo synthesis of this important enzyme cofactor. Predominant soil cobalamin producers were associated with the Proteobacteria, Actinobacteria, Firmicutes, Nitrospirae, and Thaumarchaeota. In contrast, a much larger proportion of abundant soil genera lacked cobalamin synthesis genes and instead were associated with gene sequences encoding cobalamin transport and cobalamin-dependent enzymes. The enrichment of DMB and corresponding DMB synthesis genes, relative to corrin ring synthesis genes, suggests an important role for cobalamin remodelers in terrestrial habitats. Together, our results indicate that microbial cobalamin production and repair serve as keystone functions that are significantly correlated with microbial community size, diversity, and biogeochemistry of terrestrial ecosystems.
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10
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Durán-Viseras A, Andrei AS, Ghai R, Sánchez-Porro C, Ventosa A. New Halonotius Species Provide Genomics-Based Insights Into Cobalamin Synthesis in Haloarchaea. Front Microbiol 2019; 10:1928. [PMID: 31507553 PMCID: PMC6719526 DOI: 10.3389/fmicb.2019.01928] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/05/2019] [Indexed: 11/13/2022] Open
Abstract
Hypersaline aquatic and terrestrial ecosystems display a cosmopolitan distribution. These environments teem with microbes and harbor a plethora of prokaryotic lineages that evaded ecological characterization due to the prior inability to cultivate them or to access their genomic information. In order to close the current knowledge gap, we performed two sampling and isolation campaigns in the saline soils of the Odiel Saltmarshes and the salterns of Isla Cristina (Huelva, Spain). From the isolated haloarchaeal strains subjected to high-throughput phylogenetic screening, two were chosen (F15BT and F9-27T) for physiological and genomic characterization due of their relatedness to the genus Halonotius. Comparative genomic analyses were carried out between the isolated strains and the genomes of previously described species Halonotius pteroides CECT 7525T, Halonotius aquaticus F13-13T and environmentaly recovered metagenome-assembled representatives of the genus Halonotius. The topology of the phylogenomic tree showed agreement with the phylogenetic ones based on 16S rRNA and rpoB' genes, and together with average amino acid and nucleotide identities suggested the two strains as novel species within the genus. We propose the names Halonotius terrestris sp. nov. (type strain F15BT = CECT 9688T = CCM 8954T) and Halonotius roseus sp. nov. (type strain F9-27T = CECT 9745T = CCM 8956T) for these strains. Comparative genomic analyses within the genus highlighted a typical salt-in signature, characterized by acidic proteomes with low isoelectric points, and indicated heterotrophic aerobic lifestyles. Genome-scale metabolic reconstructions revealed that the newly proposed species encode all the necessary enzymatic reactions involved in cobalamin (vitamin B12) biosynthesis. Based on the worldwide distribution of the genus and its abundance in hypersaline habitats we postulate that its members perform a critical function by being able to provide "expensive" commodities (i.e., vitamin B12) to the halophilic microbial communities at large.
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Affiliation(s)
- Ana Durán-Viseras
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Adrian-Stefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czechia
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czechia
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
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11
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Quantification of Vitamin B 12-Related Proteins in Marine Microbial Systems Using Selected Reaction Monitoring Mass Spectrometry. Methods Mol Biol 2019. [PMID: 30298249 DOI: 10.1007/978-1-4939-8728-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Mass spectrometry-based proteomic approaches to studying microbial systems enable assessment of taxonomically resolved functional capacity. A subset of these proteomic approaches are absolutely quantitative, enabling comparisons of protein expression patterns between different studies and across environments. This chapter outlines a method for applying quantitative assays in marine microbial communities, using proteins involved in vitamin B12 (cobalamin) utilization and production as specific examples. This approach involves identifying important protein targets, determining taxonomic resolution of the required assays, identifying suitable peptides, developing and optimizing liquid chromatography-selected reaction monitoring mass spectrometry assays (LC-SRM-MS), and processing the resulting data. Implementing the method outlined here results in measurements (fmol diagnostic peptide per μg of total bulk protein) that, in this case, define the nutritional status of microbial community members with respect to vitamin B12, and are comparable across and between marine microbial systems.
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12
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Uneven distribution of cobamide biosynthesis and dependence in bacteria predicted by comparative genomics. ISME JOURNAL 2018; 13:789-804. [PMID: 30429574 PMCID: PMC6461909 DOI: 10.1038/s41396-018-0304-9] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/14/2018] [Accepted: 10/04/2018] [Indexed: 11/08/2022]
Abstract
The vitamin B12 family of cofactors known as cobamides are essential for a variety of microbial metabolisms. We used comparative genomics of 11,000 bacterial species to analyze the extent and distribution of cobamide production and use across bacteria. We find that 86% of bacteria in this data set have at least one of 15 cobamide-dependent enzyme families, but only 37% are predicted to synthesize cobamides de novo. The distribution of cobamide biosynthesis and use vary at the phylum level. While 57% of Actinobacteria are predicted to biosynthesize cobamides, only 0.6% of Bacteroidetes have the complete pathway, yet 96% of species in this phylum have cobamide-dependent enzymes. The form of cobamide produced by the bacteria could be predicted for 58% of cobamide-producing species, based on the presence of signature lower ligand biosynthesis and attachment genes. Our predictions also revealed that 17% of bacteria have partial biosynthetic pathways, yet have the potential to salvage cobamide precursors. Bacteria with a partial cobamide biosynthesis pathway include those in a newly defined, experimentally verified category of bacteria lacking the first step in the biosynthesis pathway. These predictions highlight the importance of cobamide and cobamide precursor salvaging as examples of nutritional dependencies in bacteria.
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13
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Timmins-Schiffman E, Mikan MP, Ting YS, Harvey HR, Nunn BL. MS analysis of a dilution series of bacteria:phytoplankton to improve detection of low abundance bacterial peptides. Sci Rep 2018; 8:9276. [PMID: 29915279 PMCID: PMC6006377 DOI: 10.1038/s41598-018-27650-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 06/06/2018] [Indexed: 11/17/2022] Open
Abstract
Assigning links between microbial activity and biogeochemical cycles in the ocean is a primary objective for ecologists and oceanographers. Bacteria represent a small ecosystem component by mass, but act as the nexus for both nutrient transformation and organic matter recycling. There are limited methods to explore the full suite of active bacterial proteins largely responsible for degradation. Mass spectrometry (MS)-based proteomics now has the potential to document bacterial physiology within these complex systems. Global proteome profiling using MS, known as data dependent acquisition (DDA), is limited by the stochastic nature of ion selection, decreasing the detection of low abundance peptides. The suitability of MS-based proteomics methods in revealing bacterial signatures outnumbered by phytoplankton proteins was explored using a dilution series of pure bacteria (Ruegeria pomeroyi) and diatoms (Thalassiosira pseudonana). Two common acquisition strategies were utilized: DDA and selected reaction monitoring (SRM). SRM improved detection of bacterial peptides at low bacterial cellular abundance that were undetectable with DDA from a wide range of physiological processes (e.g. amino acid synthesis, lipid metabolism, and transport). We demonstrate the benefits and drawbacks of two different proteomic approaches for investigating species-specific physiological processes across relative abundances of bacteria that vary by orders of magnitude.
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Affiliation(s)
| | - Molly P Mikan
- Old Dominion University, Department of Ocean, Earth, and Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Ying Sonia Ting
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA
- Neon Therapeutics, Boston, MA, 02139, USA
| | - H Rodger Harvey
- Old Dominion University, Department of Ocean, Earth, and Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Brook L Nunn
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA.
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14
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Santos JA, Rempel S, Mous ST, Pereira CT, Ter Beek J, de Gier JW, Guskov A, Slotboom DJ. Functional and structural characterization of an ECF-type ABC transporter for vitamin B12. eLife 2018; 7:35828. [PMID: 29809140 PMCID: PMC5997447 DOI: 10.7554/elife.35828] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/26/2018] [Indexed: 01/01/2023] Open
Abstract
Vitamin B12 (cobalamin) is the most complex B-type vitamin and is synthetized exclusively in a limited number of prokaryotes. Its biologically active variants contain rare organometallic bonds, which are used by enzymes in a variety of central metabolic pathways such as L-methionine synthesis and ribonucleotide reduction. Although its biosynthesis and role as co-factor are well understood, knowledge about uptake of cobalamin by prokaryotic auxotrophs is scarce. Here, we characterize a cobalamin-specific ECF-type ABC transporter from Lactobacillus delbrueckii, ECF-CbrT, and demonstrate that it mediates the specific, ATP-dependent uptake of cobalamin. We solved the crystal structure of ECF-CbrT in an apo conformation to 3.4 Å resolution. Comparison with the ECF transporter for folate (ECF-FolT2) from the same organism, reveals how the identical ECF module adjusts to interact with the different substrate binding proteins FolT2 and CbrT. ECF-CbrT is unrelated to the well-characterized B12 transporter BtuCDF, but their biochemical features indicate functional convergence.
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Affiliation(s)
- Joana A Santos
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Stephan Rempel
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Sandra Tm Mous
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | | | - Josy Ter Beek
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Jan-Willem de Gier
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, Stockholm, Sweden
| | - Albert Guskov
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Dirk J Slotboom
- Groningen Biomolecular and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
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15
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Delmont TO, Eren AM, Vineis JH, Post AF. Genome reconstructions indicate the partitioning of ecological functions inside a phytoplankton bloom in the Amundsen Sea, Antarctica. Front Microbiol 2015; 6:1090. [PMID: 26579075 PMCID: PMC4620155 DOI: 10.3389/fmicb.2015.01090] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 09/22/2015] [Indexed: 11/30/2022] Open
Abstract
Antarctica polynyas support intense phytoplankton blooms, impacting their environment by a substantial depletion of inorganic carbon and nutrients. These blooms are dominated by the colony-forming haptophyte Phaeocystis antarctica and they are accompanied by a distinct bacterial population. Yet, the ecological role these bacteria may play in P. antarctica blooms awaits elucidation of their functional gene pool and of the geochemical activities they support. Here, we report on a metagenome (~160 million reads) analysis of the microbial community associated with a P. antarctica bloom event in the Amundsen Sea polynya (West Antarctica). Genomes of the most abundant Bacteroidetes and Proteobacteria populations have been reconstructed and a network analysis indicates a strong functional partitioning of these bacterial taxa. Three of them (SAR92, and members of the Oceanospirillaceae and Cryomorphaceae) are found in close association with P. antarctica colonies. Distinct features of their carbohydrate, nitrogen, sulfur and iron metabolisms may serve to support mutualistic relationships with P. antarctica. The SAR92 genome indicates a specialization in the degradation of fatty acids and dimethylsulfoniopropionate (compounds released by P. antarctica) into dimethyl sulfide, an aerosol precursor. The Oceanospirillaceae genome carries genes that may enhance algal physiology (cobalamin synthesis). Finally, the Cryomorphaceae genome is enriched in genes that function in cell or colony invasion. A novel pico-eukaryote, Micromonas related genome (19.6 Mb, ~94% completion) was also recovered. It contains the gene for an anti-freeze protein, which is lacking in Micromonas at lower latitudes. These draft genomes are representative for abundant microbial taxa across the Southern Ocean surface.
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Affiliation(s)
- Tom O. Delmont
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological LaboratoryWoods Hole, MA, USA
| | - A. Murat Eren
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological LaboratoryWoods Hole, MA, USA
| | - Joseph H. Vineis
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological LaboratoryWoods Hole, MA, USA
| | - Anton F. Post
- Coastal Resources Center, Graduate School of Oceanography, University of Rhode IslandNarragansett, RI, USA
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16
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Phytoplankton-bacterial interactions mediate micronutrient colimitation at the coastal Antarctic sea ice edge. Proc Natl Acad Sci U S A 2015. [PMID: 26221022 DOI: 10.1073/pnas.1501615112] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Southern Ocean primary productivity plays a key role in global ocean biogeochemistry and climate. At the Southern Ocean sea ice edge in coastal McMurdo Sound, we observed simultaneous cobalamin and iron limitation of surface water phytoplankton communities in late Austral summer. Cobalamin is produced only by bacteria and archaea, suggesting phytoplankton-bacterial interactions must play a role in this limitation. To characterize these interactions and investigate the molecular basis of multiple nutrient limitation, we examined transitions in global gene expression over short time scales, induced by shifts in micronutrient availability. Diatoms, the dominant primary producers, exhibited transcriptional patterns indicative of co-occurring iron and cobalamin deprivation. The major contributor to cobalamin biosynthesis gene expression was a gammaproteobacterial population, Oceanospirillaceae ASP10-02a. This group also contributed significantly to metagenomic cobalamin biosynthesis gene abundance throughout Southern Ocean surface waters. Oceanospirillaceae ASP10-02a displayed elevated expression of organic matter acquisition and cell surface attachment-related genes, consistent with a mutualistic relationship in which they are dependent on phytoplankton growth to fuel cobalamin production. Separate bacterial groups, including Methylophaga, appeared to rely on phytoplankton for carbon and energy sources, but displayed gene expression patterns consistent with iron and cobalamin deprivation. This suggests they also compete with phytoplankton and are important cobalamin consumers. Expression patterns of siderophore- related genes offer evidence for bacterial influences on iron availability as well. The nature and degree of this episodic colimitation appear to be mediated by a series of phytoplankton-bacterial interactions in both positive and negative feedback loops.
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17
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Delmont TO, Hammar KM, Ducklow HW, Yager PL, Post AF. Phaeocystis antarctica blooms strongly influence bacterial community structures in the Amundsen Sea polynya. Front Microbiol 2014; 5:646. [PMID: 25566197 PMCID: PMC4271704 DOI: 10.3389/fmicb.2014.00646] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 11/07/2014] [Indexed: 11/21/2022] Open
Abstract
Rising temperatures and changing winds drive the expansion of the highly productive polynyas (open water areas surrounded by sea ice) abutting the Antarctic continent. Phytoplankton blooms in polynyas are often dominated by the haptophyte Phaeocystis antarctica, and they generate the organic carbon that enters the resident microbial food web. Yet, little is known about how Phaeocystis blooms shape bacterial community structures and carbon fluxes in these systems. We identified the bacterial communities that accompanied a Phaeocystis bloom in the Amundsen Sea polynya during the austral summers of 2007–2008 and 2010–2011. These communities are distinct from those determined for the Antarctic Circumpolar Current (ACC) and off the Palmer Peninsula. Diversity patterns for most microbial taxa in the Amundsen Sea depended on location (e.g., waters abutting the pack ice near the shelf break and at the edge of the Dotson glacier) and depth, reflecting different niche adaptations within the confines of this isolated ecosystem. Inside the polynya, P. antarctica coexisted with the bacterial taxa Polaribacter sensu lato, a cryptic Oceanospirillum, SAR92 and Pelagibacter. These taxa were dominated by a single oligotype (genotypes partitioned by Shannon entropy analysis) and together contributed up to 73% of the bacterial community. Size fractionation of the bacterial community [<3 μm (free-living bacteria) vs. >3 μm (particle-associated bacteria)] identified several taxa (especially SAR92) that were preferentially associated with Phaeocystis colonies, indicative of a distinct role in Phaeocystis bloom ecology. In contrast, particle-associated bacteria at 250 m depth were enriched in Colwellia and members of the Cryomorphaceae suggesting that they play important roles in the decay of Phaeocystis blooms.
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Affiliation(s)
- Tom O Delmont
- Marine Biology Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution Woods Hole, MA, USA
| | - Katherine M Hammar
- Marine Biology Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution Woods Hole, MA, USA
| | - Hugh W Ducklow
- Lamont Doherty Earth Observatory, Columbia University Palisades, NY, USA
| | - Patricia L Yager
- Department of Marine Sciences, University of Georgia Athens, GA, USA
| | - Anton F Post
- Marine Biology Laboratory, Josephine Bay Paul Center for Comparative Molecular Biology and Evolution Woods Hole, MA, USA
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18
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Palenik B. Molecular mechanisms by which marine phytoplankton respond to their dynamic chemical environment. ANNUAL REVIEW OF MARINE SCIENCE 2014; 7:325-340. [PMID: 25195866 DOI: 10.1146/annurev-marine-010814-015639] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Marine scientists have long been interested in the interactions of marine phytoplankton with their chemical environments. Nutrient availability clearly controls carbon fixation on a global scale, but the interactions between phytoplankton and nutrients are complex and include both short-term responses (seconds to minutes) and longer-term evolutionary adaptations. This review outlines how genomics and functional genomics approaches are providing a better understanding of these complex interactions, especially for cyanobacteria and diatoms, for which the genome sequences of multiple model organisms are available. Transporters and related genes are emerging as the most likely candidates for biomarkers in stress-specific studies, but other genes are also possible candidates. One surprise has been the important role of horizontal gene transfer in mediating chemical-biological interactions.
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Affiliation(s)
- Brian Palenik
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0202;
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19
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Aquatic metagenomes implicate Thaumarchaeota in global cobalamin production. ISME JOURNAL 2014; 9:461-71. [PMID: 25126756 PMCID: PMC4303638 DOI: 10.1038/ismej.2014.142] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/02/2014] [Accepted: 07/03/2014] [Indexed: 01/06/2023]
Abstract
Cobalamin (vitamin B12) is a complex metabolite and essential cofactor required by many branches of life, including most eukaryotic phytoplankton. Algae and other cobalamin auxotrophs rely on environmental cobalamin supplied from a relatively small set of cobalamin-producing prokaryotic taxa. Although several Bacteria have been implicated in cobalamin biosynthesis and associated with algal symbiosis, the involvement of Archaea in cobalamin production is poorly understood, especially with respect to the Thaumarchaeota. Based on the detection of cobalamin synthesis genes in available thaumarchaeotal genomes, we hypothesized that Thaumarchaeota, which are ubiquitous and abundant in aquatic environments, have an important role in cobalamin biosynthesis within global aquatic ecosystems. To test this hypothesis, we examined cobalamin synthesis genes across sequenced thaumarchaeotal genomes and 430 metagenomes from a diverse range of marine, freshwater and hypersaline environments. Our analysis demonstrates that all available thaumarchaeotal genomes possess cobalamin synthesis genes, predominantly from the anaerobic pathway, suggesting widespread genetic capacity for cobalamin synthesis. Furthermore, although bacterial cobalamin genes dominated most surface marine metagenomes, thaumarchaeotal cobalamin genes dominated metagenomes from polar marine environments, increased with depth in marine water columns, and displayed seasonality, with increased winter abundance observed in time-series datasets (e.g., L4 surface water in the English Channel). Our results also suggest niche partitioning between thaumarchaeotal and cyanobacterial ribosomal and cobalamin synthesis genes across all metagenomic datasets analyzed. These results provide strong evidence for specific biogeographical distributions of thaumarchaeotal cobalamin genes, expanding our understanding of the global biogeochemical roles played by Thaumarchaeota in aquatic environments.
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20
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Graham LE, Knack JJ, Piotrowski MJ, Wilcox LW, Cook ME, Wellman CH, Taylor W, Lewis LA, Arancibia-Avila P. Lacustrine Nostoc (Nostocales) and associated microbiome generate a new type of modern clotted microbialite. JOURNAL OF PHYCOLOGY 2014; 50:280-291. [PMID: 26988185 DOI: 10.1111/jpy.12152] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 10/24/2013] [Indexed: 06/05/2023]
Abstract
Microbialites are mineral formations formed by microbial communities that are often dominated by cyanobacteria. Carbonate microbialites, known from Proterozoic times through the present, are recognized for sequestering globally significant amounts of inorganic carbon. Recent ecological work has focused on microbial communities dominated by cyanobacteria that produce microbial mats and laminate microbialites (stromatolites). However, the taxonomic composition and functions of microbial communities that generate distinctive clotted microbialites (thrombolites) are less well understood. Here, microscopy and deep shotgun sequencing were used to characterize the microbiome (microbial taxa and their genomes) associated with a single cyanobacterial host linked by 16S sequences to Nostoc commune Vaucher ex Bornet & Flahault, which dominates abundant littoral clotted microbialites in shallow, subpolar, freshwater Laguna Larga in southern Chile. Microscopy and energy-dispersive X-ray spectroscopy suggested the hypothesis that adherent hollow carbonate spheres typical of the clotted microbialite begin development on the rigid curved outer surfaces of the Nostoc balls. A surface biofilm included >50 nonoxygenic bacterial genera (taxa other than Nostoc) that indicate diverse ecological functions. The Laguna Larga Nostoc microbiome included the sulfate reducers Desulfomicrobium and Sulfospirillum and genes encoding all known proteins specific to sulfate reduction, a process known to facilitate carbonate deposition by increasing pH. Sequences indicating presence of nostocalean and other types of nifH, nostocalean sulfide:ferredoxin oxidoreductase (indicating anoxygenic photosynthesis), and biosynthetic pathways for the secondary products scytonemin, mycosporine, and microviridin toxin were identified. These results allow comparisons with microbiota and microbiomes of other algae and illuminate biogeochemical roles of ancient microbialites.
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Affiliation(s)
- Linda E Graham
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, Wisconsin, 53606, USA
| | - Jennifer J Knack
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, Wisconsin, 53606, USA
| | - Michael J Piotrowski
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, Wisconsin, 53606, USA
| | - Lee W Wilcox
- Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, Wisconsin, 53606, USA
| | - Martha E Cook
- School of Biological Sciences, Illinois State University, Normal, Illinois, 61790, USA
| | - Charles H Wellman
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Wilson Taylor
- Department of Biology, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, 54702, USA
| | - Louise A Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, 06269, USA
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21
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Yu Y, Zhou M, Kirsch F, Xu C, Zhang L, Wang Y, Jiang Z, Wang N, Li J, Eitinger T, Yang M. Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters. Cell Res 2013; 24:267-77. [PMID: 24366337 PMCID: PMC3945884 DOI: 10.1038/cr.2013.172] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/14/2013] [Accepted: 10/29/2013] [Indexed: 11/09/2022] Open
Abstract
The energy-coupling factor (ECF) transporters are multi-subunit protein complexes that mediate uptake of transition-metal ions and vitamins in about 50% of the prokaryotes, including bacteria and archaea. Biological and structural studies have been focused on ECF transporters for vitamins, but the molecular mechanism by which ECF systems transport metal ions from the environment remains unknown. Here we report the first crystal structure of a NikM, TtNikM2, the substrate-binding component (S component) of an ECF-type nickel transporter from Thermoanaerobacter tengcongensis. In contrast to the structures of the vitamin-specific S proteins with six transmembrane segments (TSs), TtNikM2 possesses an additional TS at its N-terminal region, resulting in an extracellular N-terminus. The highly conserved N-terminal loop inserts into the center of TtNikM2 and occludes a region corresponding to the substrate-binding sites of the vitamin-specific S components. Nickel binds to NikM via its coordination to four nitrogen atoms, which are derived from Met1, His2 and His67 residues. These nitrogen atoms form an approximately square-planar geometry, similar to that of the metal ion-binding sites in the amino-terminal Cu(2+)- and Ni(2+)-binding (ATCUN) motif. Replacements of residues in NikM contributing to nickel coordination compromised the Ni-transport activity. Furthermore, systematic quantum chemical investigation indicated that this geometry enables NikM to also selectively recognize Co(2+). Indeed, the structure of TtNikM2 containing a bound Co(2+) ion has almost no conformational change compared to the structure that contains a nickel ion. Together, our data reveal an evolutionarily conserved mechanism underlying the metal selectivity of EcfS proteins, and provide insights into the ion-translocation process mediated by ECF transporters.
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Affiliation(s)
- You Yu
- 1] MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China [2] Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Mingze Zhou
- 1] MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China [2] Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Franziska Kirsch
- Humboldt-Universität zu Berlin, Institut für Biologie/Mikrobiologie, 10115 Berlin, Germany
| | - Congqiao Xu
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Li Zhang
- 1] MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China [2] Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yu Wang
- Shanghai Synchrotron Radiation Facilities, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
| | - Zheng Jiang
- Shanghai Synchrotron Radiation Facilities, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
| | - Na Wang
- 1] MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China [2] Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jun Li
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Thomas Eitinger
- Humboldt-Universität zu Berlin, Institut für Biologie/Mikrobiologie, 10115 Berlin, Germany
| | - Maojun Yang
- 1] MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China [2] Department of Pharmacology and Pharmaceutical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
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22
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Glass JB, Yu H, Steele JA, Dawson KS, Sun S, Chourey K, Pan C, Hettich RL, Orphan VJ. Geochemical, metagenomic and metaproteomic insights into trace metal utilization by methane-oxidizing microbial consortia in sulphidic marine sediments. Environ Microbiol 2013; 16:1592-611. [DOI: 10.1111/1462-2920.12314] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 10/13/2013] [Indexed: 01/17/2023]
Affiliation(s)
- Jennifer B. Glass
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena CA 91125 USA
| | - Hang Yu
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena CA 91125 USA
| | - Joshua A. Steele
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena CA 91125 USA
| | - Katherine S. Dawson
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena CA 91125 USA
| | - Shulei Sun
- The CAMERA Project; University of California San Diego; San Diego CA 92093 USA
| | - Karuna Chourey
- Chemical Sciences Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
| | - Chongle Pan
- Chemical Sciences Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
| | - Robert L. Hettich
- Chemical Sciences Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
| | - Victoria J. Orphan
- Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena CA 91125 USA
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23
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Abstract
Atypical protein kinases of the RIO (right open reading frame) kinase family are found in all three domains of life, emphasizing their essential function. In all archaeal genomes sequenced to date, typically two, but at least one, members of the RIO kinase family have been identified. Although the function of RIO kinases in Archaea remains to be resolved, bioinformatics analysis (e.g. comparison of the phylogenetic distribution and gene neighbourhood analysis, as well as interaction analysis) in combination with the available phosphoproteome study of Sulfolobus solfataricus provided some first hints to the possible function as well as revealed some putative target proteins for RIO kinases in Archaea. This study suggests a possible function of archaeal RIO kinases in RNA and/or DNA binding/processing translation initiation or ribosomal biogenesis resembling the assumed physiological role in yeast.
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24
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Thi Vu H, Itoh H, Ishii S, Senoo K, Otsuka S. Identification and phylogenetic characterization of cobalamin biosynthetic genes of Ensifer adhaerens. Microbes Environ 2012; 28:153-5. [PMID: 23257908 PMCID: PMC4070679 DOI: 10.1264/jsme2.me12069] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Ensifer adhaerens CSBa was screened as a cobalamin producer. The draft genome sequence revealed that the strain possesses 22 cobalamin biosynthetic genes (cob genes). The cob gene arrangement on the genome of E. adhaerens CSBa was similar to that of other Ensifer species, and most similar to that of Pseudomonas denitrificans SC510. The cobN sequence phylogeny was generally congruent with that of the 16S rRNA gene, and it is suggeted that E. adhaerens CSBa might have inherited the cob genes from common ancestors of the Ensifer species. It was also suggested that the cob genes can be laterally transferred.
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Affiliation(s)
- Hoan Thi Vu
- Department of Applied Biological Chemistry, The University of Tokyo, Tokyo, Japan
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25
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Bertrand EM, Allen AE. Influence of vitamin B auxotrophy on nitrogen metabolism in eukaryotic phytoplankton. Front Microbiol 2012; 3:375. [PMID: 23091473 PMCID: PMC3476827 DOI: 10.3389/fmicb.2012.00375] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 10/02/2012] [Indexed: 01/22/2023] Open
Abstract
While nitrogen availability is known to limit primary production in large parts of the ocean, vitamin starvation amongst eukaryotic phytoplankton is becoming increasingly recognized as an oceanographically relevant phenomenon. Cobalamin (B(12)) and thiamine (B(1)) auxotrophy are widespread throughout eukaryotic phytoplankton, with over 50% of cultured isolates requiring B(12) and 20% requiring B(1). The frequency of vitamin auxotrophy in harmful algal bloom species is even higher. Instances of colimitation between nitrogen and B vitamins have been observed in marine environments, and interactions between these nutrients have been shown to impact phytoplankton species composition. This review surveys available data, including relevant gene expression patterns, to evaluate the potential for interactive effects of nitrogen and vitamin B(12) and B(1) starvation in eukaryotic phytoplankton. B(12) plays essential roles in amino acid and one-carbon metabolism, while B(1) is important for primary carbohydrate and amino acid metabolism and likely useful as an anti-oxidant. Here we will focus on three potential metabolic interconnections between vitamin, nitrogen, and sulfur metabolism that may have ramifications for the role of vitamin and nitrogen scarcities in driving ocean productivity and species composition. These include: (1) B(12), B(1), and N starvation impacts on osmolyte and antioxidant production, (2) B(12) and B(1) starvation impacts on polyamine biosynthesis, and (3) influence of B(12) and B(1) starvation on the diatom urea cycle and amino acid recycling through impacts on the citric acid cycle. We evaluate evidence for these interconnections and identify oceanographic contexts in which each may impact rates of primary production and phytoplankton community composition. Major implications include that B(12) and B(1) deprivation may impair the ability of phytoplankton to recover from nitrogen starvation and that changes in vitamin and nitrogen availability may synergistically impact harmful algal bloom formation.
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Affiliation(s)
- Erin M Bertrand
- Department of Microbial and Environmental Genomics, J. Craig Venter Institute San Diego, CA, USA
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26
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Koch F, Hattenrath-Lehmann TK, Goleski JA, Sañudo-Wilhelmy S, Fisher NS, Gobler CJ. Vitamin b(1) and b(12) uptake and cycling by plankton communities in coastal ecosystems. Front Microbiol 2012; 3:363. [PMID: 23091470 PMCID: PMC3469840 DOI: 10.3389/fmicb.2012.00363] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 09/24/2012] [Indexed: 11/13/2022] Open
Abstract
While vitamin B12 has recently been shown to co-limit the growth of coastal phytoplankton assemblages, the cycling of B-vitamins in coastal ecosystems is poorly understood as planktonic uptake rates of vitamins B1 and B12 have never been quantified in tandem in any aquatic ecosystem. The goal of this study was to establish the relationships between plankton community composition, carbon fixation, and B-vitamin assimilation in two contrasting estuarine systems. We show that, although B-vitamin concentrations were low (pM), vitamin concentrations and uptake rates were higher within a more eutrophic estuary and that vitamin B12 uptake rates were significantly correlated with rates of primary production. Eutrophic sites hosted larger bacterial and picoplankton abundances with larger carbon normalized vitamin uptake rates. Although the >2 μm phytoplankton biomass was often dominated by groups with a high incidence of vitamin auxotrophy (dinoflagellates and diatoms), picoplankton (<2 μm) were always responsible for the majority of B12-vitamin uptake. Multiple lines of evidence suggest that heterotrophic bacteria were the primary users of vitamins among the picoplankton during this study. Nutrient/vitamin amendment experiments demonstrated that, in the Summer and Fall, vitamin B12 occasionally limited or co-limited the accumulation of phytoplankton biomass together with nitrogen. Combined with prior studies, these findings suggest that picoplankton are the primary producers and users of B-vitamins in some coastal ecosystems and that rapid uptake of B-vitamins by heterotrophic bacteria may sometimes deprive larger phytoplankton of these micronutrients and thus influence phytoplankton species succession.
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Affiliation(s)
- Florian Koch
- School of Marine and Atmospheric Sciences, Stony Brook University Southampton, NY, USA
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27
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Abstract
B vitamins are some of the most commonly required biochemical cofactors in living systems. Therefore, cellular metabolism of marine vitamin-requiring (auxotrophic) phytoplankton and bacteria would likely be significantly compromised if B vitamins (thiamin B(1), riboflavin B(2), pyridoxine B(6), biotin B(7), and cobalamin B(12)) were unavailable. However, the factors controlling the synthesis, ambient concentrations, and uptake of these key organic compounds in the marine environment are still not well understood. Here, we report vertical distributions of five B vitamins (and the amino acid methionine) measured simultaneously along a latitudinal gradient through the contrasting oceanographic regimes of the southern California-Baja California coast in the Northeast Pacific margin. Although vitamin concentrations ranged from below the detection limits of our technique to 30 pM for B(2) and B(12) and to ∼500 pM for B(1), B(6), and B(7), each vitamin showed a different geographical and depth distribution. Vitamin concentrations were independent of each other and of inorganic nutrient levels, enriched primarily in the upper mesopelagic zone (depth of 100-300 m), and associated with water mass origin. Moreover, vitamin levels were below our detection limits (ranging from ≤0.18 pM for B(12) to ≤0.81 pM for B(1)) in extensive areas (100s of kilometers) of the coastal ocean, and thus may exert important constraints on the taxonomic composition of phytoplankton communities, and potentially also on rates of primary production and carbon sequestration.
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28
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Influence of cobalamin scarcity on diatom molecular physiology and identification of a cobalamin acquisition protein. Proc Natl Acad Sci U S A 2012; 109:E1762-71. [PMID: 22652568 DOI: 10.1073/pnas.1201731109] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diatoms are responsible for ~40% of marine primary production and are key players in global carbon cycling. There is mounting evidence that diatom growth is influenced by cobalamin (vitamin B(12)) availability. This cobalt-containing micronutrient is only produced by some bacteria and archaea but is required by many diatoms and other eukaryotic phytoplankton. Despite its potential importance, little is known about mechanisms of cobalamin acquisition in diatoms or the impact of cobalamin scarcity on diatom molecular physiology. Proteomic profiling and RNA-sequencing transcriptomic analysis of the cultured diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana revealed three distinct strategies used by diatoms to cope with low cobalamin: increased cobalamin acquisition machinery, decreased cobalamin demand, and management of reduced methionine synthase activity through changes in folate and S-adenosyl methionine metabolism. One previously uncharacterized protein, cobalamin acquisition protein 1 (CBA1), was up to 160-fold more abundant under low cobalamin availability in both diatoms. Autologous overexpression of CBA1 revealed association with the outside of the cell and likely endoplasmic reticulum localization. Cobalamin uptake rates were elevated in strains overexpressing CBA1, directly linking this protein to cobalamin acquisition. CBA1 is unlike characterized cobalamin acquisition proteins and is the only currently identified algal protein known to be implicated in cobalamin uptake. The abundance and widespread distribution of transcripts encoding CBA1 in environmental samples suggests that cobalamin is an important nutritional factor for phytoplankton. Future study of CBA1 and other molecular signatures of cobalamin scarcity identified here will yield insight into the evolution of cobalamin utilization and facilitate monitoring of cobalamin starvation in oceanic diatom communities.
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29
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Merchant SS, Helmann JD. Elemental economy: microbial strategies for optimizing growth in the face of nutrient limitation. Adv Microb Physiol 2012; 60:91-210. [PMID: 22633059 PMCID: PMC4100946 DOI: 10.1016/b978-0-12-398264-3.00002-4] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microorganisms play a dominant role in the biogeochemical cycling of nutrients. They are rightly praised for their facility for fixing both carbon and nitrogen into organic matter, and microbial driven processes have tangibly altered the chemical composition of the biosphere and its surrounding atmosphere. Despite their prodigious capacity for molecular transformations, microorganisms are powerless in the face of the immutability of the elements. Limitations for specific elements, either fleeting or persisting over eons, have left an indelible trace on microbial genomes, physiology, and their very atomic composition. We here review the impact of elemental limitation on microbes, with a focus on selected genetic model systems and representative microbes from the ocean ecosystem. Evolutionary adaptations that enhance growth in the face of persistent or recurrent elemental limitations are evident from genome and proteome analyses. These range from the extreme (such as dispensing with a requirement for a hard to obtain element) to the extremely subtle (changes in protein amino acid sequences that slightly, but significantly, reduce cellular carbon, nitrogen, or sulfur demand). One near-universal adaptation is the development of sophisticated acclimation programs by which cells adjust their chemical composition in response to a changing environment. When specific elements become limiting, acclimation typically begins with an increased commitment to acquisition and a concomitant mobilization of stored resources. If elemental limitation persists, the cell implements austerity measures including elemental sparing and elemental recycling. Insights into these fundamental cellular properties have emerged from studies at many different levels, including ecology, biological oceanography, biogeochemistry, molecular genetics, genomics, and microbial physiology. Here, we present a synthesis of these diverse studies and attempt to discern some overarching themes.
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Affiliation(s)
- Sabeeha S. Merchant
- Institute for Genomics and Proteomics and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, 14853-8101
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30
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Saito MA, Bulygin VV, Moran DM, Taylor C, Scholin C. Examination of microbial proteome preservation techniques applicable to autonomous environmental sample collection. Front Microbiol 2011; 2:215. [PMID: 22069397 PMCID: PMC3209654 DOI: 10.3389/fmicb.2011.00215] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 10/10/2011] [Indexed: 01/10/2023] Open
Abstract
Improvements in temporal and spatial sampling frequency have the potential to open new windows into the understanding of marine microbial dynamics. In recent years, efforts have been made to allow automated samplers to collect microbial biomass for DNA/RNA analyses from moored observatories and autonomous underwater vehicles. Measurements of microbial proteins are also of significant interest given their biogeochemical importance as enzymes that catalyze reactions and transporters that interface with the environment. We examined the influence of five preservatives solutions (SDS-extraction buffer, ethanol, trichloroacetic acid, B-PER, and RNAlater) on the proteome integrity of the marine cyanobacterium Synechococcus WH8102 after 4 weeks of storage at room temperature. Four approaches were used to assess degradation: total protein recovery, band integrity on an SDS detergent polyacrylamide electrophoresis (SDS-PAGE) gel, and number of protein identifications and relative abundances by 1-dimensional LC–MS/MS proteomic analyses. Total protein recoveries from the preserved samples were lower than the frozen control due to processing losses, which could be corrected for with internal standardization. The trichloroacetic acid preserved sample showed significant loss of protein band integrity on the SDS-PAGE gel. The RNAlater preserved sample showed the highest number of protein identifications (103% relative to the control; 520 ± 31 identifications in RNAlater versus 504 ± 4 in the control), equivalent to the frozen control. Relative abundances of individual proteins in the RNAlater treatment were quite similar to that of the frozen control (average ratio of 1.01 ± 0.27 for the 50 most abundant proteins), while the SDS-extraction buffer, ethanol, and B-PER all showed significant decreases in both number of identifications and relative abundances of individual proteins. Based on these findings, RNAlater was an effective proteome preservative, although further study is warranted on additional marine microbes.
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Affiliation(s)
- Mak A Saito
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution Woods Hole, MA, USA
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31
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Bertrand EM, Saito MA, Lee PA, Dunbar RB, Sedwick PN, DiTullio GR. Iron limitation of a springtime bacterial and phytoplankton community in the ross sea: implications for vitamin b(12) nutrition. Front Microbiol 2011; 2:160. [PMID: 21886638 PMCID: PMC3155878 DOI: 10.3389/fmicb.2011.00160] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 07/13/2011] [Indexed: 11/14/2022] Open
Abstract
The Ross Sea is home to some of the largest phytoplankton blooms in the Southern Ocean. Primary production in this system has previously been shown to be iron limited in the summer and periodically iron and vitamin B(12) colimited. In this study, we examined trace metal limitation of biological activity in the Ross Sea in the austral spring and considered possible implications for vitamin B(12) nutrition. Bottle incubation experiments demonstrated that iron limited phytoplankton growth in the austral spring while B(12), cobalt, and zinc did not. This is the first demonstration of iron limitation in a Phaeocystis antarctica-dominated, early season Ross Sea phytoplankton community. The lack of B(12) limitation in this location is consistent with previous Ross Sea studies in the austral summer, wherein vitamin additions did not stimulate P. antarctica growth and B(12) was limiting only when bacterial abundance was low. Bottle incubation experiments and a bacterial regrowth experiment also revealed that iron addition directly enhanced bacterial growth. B(12) uptake measurements in natural water samples and in an iron fertilized bottle incubation demonstrated that bacteria serve not only as a source for vitamin B(12), but also as a significant sink, and that iron additions enhanced B(12) uptake rates in phytoplankton but not bacteria. Additionally, vitamin uptake rates did not become saturated upon the addition of up to 95 pM B(12). A rapid B(12) uptake rate was observed after 13 min, which then decreased to a slower constant uptake rate over the next 52 h. Results from this study highlight the importance of iron availability in limiting early season Ross Sea phytoplankton growth and suggest that rates of vitamin B(12) production and consumption may be impacted by iron availability.
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Affiliation(s)
- Erin M. Bertrand
- MIT/WHOI Joint Program in Chemical Oceanography and Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic InstitutionWoods Hole, MA, USA
| | - Mak A. Saito
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic InstitutionWoods Hole, MA, USA
| | - Peter A. Lee
- Hollings Marine Laboratory, College of CharlestonCharleston, SC, USA
| | - Robert B. Dunbar
- Department of Environmental Earth Systems Science, Stanford UniversityStanford, CA, USA
| | - Peter N. Sedwick
- Department of Ocean, Earth and Atmospheric Sciences, Old Dominion UniversityNorfolk, VA, USA
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