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Leavitt WD, Waldbauer J, Venceslau SS, Sim MS, Zhang L, Boidi FJ, Plummer S, Diaz JM, Pereira IAC, Bradley AS. Energy flux couples sulfur isotope fractionation to proteomic and metabolite profiles in Desulfovibrio vulgaris. GEOBIOLOGY 2024; 22:e12600. [PMID: 38725144 DOI: 10.1111/gbi.12600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 01/31/2024] [Accepted: 04/18/2024] [Indexed: 07/12/2024]
Abstract
Microbial sulfate reduction is central to the global carbon cycle and the redox evolution of Earth's surface. Tracking the activity of sulfate reducing microorganisms over space and time relies on a nuanced understanding of stable sulfur isotope fractionation in the context of the biochemical machinery of the metabolism. Here, we link the magnitude of stable sulfur isotopic fractionation to proteomic and metabolite profiles under different cellular energetic regimes. When energy availability is limited, cell-specific sulfate respiration rates and net sulfur isotope fractionation inversely covary. Beyond net S isotope fractionation values, we also quantified shifts in protein expression, abundances and isotopic composition of intracellular S metabolites, and lipid structures and lipid/water H isotope fractionation values. These coupled approaches reveal which protein abundances shift directly as a function of energy flux, those that vary minimally, and those that may vary independent of energy flux and likely do not contribute to shifts in S-isotope fractionation. By coupling the bulk S-isotope observations with quantitative proteomics, we provide novel constraints for metabolic isotope models. Together, these results lay the foundation for more predictive metabolic fractionation models, alongside interpretations of environmental sulfur and sulfate reducer lipid-H isotope data.
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Affiliation(s)
- William D Leavitt
- Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire, USA
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jacob Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Sofia S Venceslau
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Min Sub Sim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
| | - Lichun Zhang
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Flavia Jaquelina Boidi
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
- Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Sydney Plummer
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
| | - Julia M Diaz
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Alexander S Bradley
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, Saint Louis, Missouri, USA
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2
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Ferreira D, Venceslau SS, Bernardino R, Preto A, Zhang L, Waldbauer JR, Leavitt WD, Pereira IAC. DsrC is involved in fermentative growth and interacts directly with the FlxABCD-HdrABC complex in Desulfovibrio vulgaris Hildenborough. Environ Microbiol 2023; 25:962-976. [PMID: 36602077 DOI: 10.1111/1462-2920.16335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 12/28/2022] [Indexed: 01/06/2023]
Abstract
DsrC is a key protein in dissimilatory sulfur metabolism, where it works as co-substrate of the dissimilatory sulfite reductase DsrAB. DsrC has two conserved cysteines in a C-terminal arm that are converted to a trisulfide upon reduction of sulfite. In sulfate-reducing bacteria, DsrC is essential and previous works suggested additional functions beyond sulfite reduction. Here, we studied whether DsrC also plays a role during fermentative growth of Desulfovibrio vulgaris Hildenborough, by studying two strains where the functionality of DsrC is impaired by a lower level of expression (IPFG07) and additionally by the absence of one conserved Cys (IPFG09). Growth studies coupled with metabolite and proteomic analyses reveal that fermentation leads to lower levels of DsrC, but impairment of its function results in reduced growth by fermentation and a shift towards more fermentative metabolism during sulfate respiration. In both respiratory and fermentative conditions, there is increased abundance of the FlxABCD-HdrABC complex and Adh alcohol dehydrogenase in IPFG09 versus the wild type, which is reflected in higher production of ethanol. Pull-down experiments confirmed a direct interaction between DsrC and the FlxABCD-HdrABC complex, through the HdrB subunit. Dissimilatory sulfur metabolism, where sulfur compounds are used for energy generation, is a key process in the ecology of anoxic environments, and is more widespread among bacteria than previously believed. Two central proteins for this type of metabolism are DsrAB dissimilatory sulfite reductase and its co-substrate DsrC. Using physiological, proteomic and biochemical studies of Desulfovibrio vulgaris Hildenborough and mutants affected in DsrC functionality, we show that DsrC is also relevant for fermentative growth of this model organism and that it interacts directly with the soluble FlxABCD-HdrABC complex that links the NAD(H) pool with dissimilatory sulfite reduction.
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Affiliation(s)
- Delfim Ferreira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sofia S Venceslau
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Raquel Bernardino
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - André Preto
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lichun Zhang
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Jacob R Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - William D Leavitt
- Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire, USA
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire, USA
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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Smith DA, Fike DA, Johnston DT, Bradley AS. Isotopic Fractionation Associated With Sulfate Import and Activation by Desulfovibrio vulgaris str. Hildenborough. Front Microbiol 2020; 11:529317. [PMID: 33072004 PMCID: PMC7531388 DOI: 10.3389/fmicb.2020.529317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 08/14/2020] [Indexed: 11/13/2022] Open
Abstract
The use of stable isotopes to trace biogeochemical sulfur cycling relies on an understanding of how isotopic fractionation is imposed by metabolic networks. We investigated the effects of the first two enzymatic steps in the dissimilatory sulfate reduction (DSR) network - sulfate permease and sulfate adenylyl transferase (Sat) - on the sulfur and oxygen isotopic composition of residual sulfate. Mutant strains of Desulfovibrio vulgaris str. Hildenborough (DvH) with perturbed expression of these enzymes were grown in batch culture, with a subset grown in continuous culture, to examine the impact of these enzymatic steps on growth rate, cell specific sulfate reduction rate and isotopic fractionations in comparison to the wild type strain. Deletion of several permease genes resulted in only small (∼1‰) changes in sulfur isotope fractionation, a difference that approaches the uncertainties of the measurement. Mutants that perturb Sat expression show higher fractionations than the wild type strain. This increase probably relates to an increased material flux between sulfate and APS, allowing an increase in the expressed fractionation of rate-limiting APS reductase. This work illustrates that flux through the initial steps of the DSR pathway can affect the fractionation imposed by the overall pathway, even though these steps are themselves likely to impose only small fractionations.
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Affiliation(s)
- Derek A Smith
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States
| | - David A Fike
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States
| | - David T Johnston
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States
| | - Alexander S Bradley
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States.,Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, United States
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Leavitt WD, Venceslau SS, Waldbauer J, Smith DA, Pereira IAC, Bradley AS. Proteomic and Isotopic Response of Desulfovibrio vulgaris to DsrC Perturbation. Front Microbiol 2019; 10:658. [PMID: 31031715 PMCID: PMC6470260 DOI: 10.3389/fmicb.2019.00658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 03/15/2019] [Indexed: 11/30/2022] Open
Abstract
Dissimilatory sulfate reduction is a microbial energy metabolism that can produce sulfur isotopic fractionations over a large range in magnitude. Calibrating sulfur isotopic fractionation in laboratory experiments allows for better interpretations of sulfur isotopes in modern sediments and ancient sedimentary rocks. The proteins involved in sulfate reduction are expressed in response to environmental conditions, and are collectively responsible for the net isotopic fractionation between sulfate and sulfide. We examined the role of DsrC, a key component of the sulfate reduction pathway, by comparing wildtype Desulfovibrio vulgaris DSM 644T to strain IPFG07, a mutant deficient in DsrC production. Both strains were cultivated in parallel chemostat reactors at identical turnover times and cell specific sulfate reduction rates. Under these conditions, sulfur isotopic fractionations between sulfate and sulfide of 17.3 ± 0.5‰ or 12.6 ± 0.5‰ were recorded for the wildtype or mutant, respectively. The enzymatic machinery that produced these different fractionations was revealed by quantitative proteomics. Results are consistent with a cellular-level response that throttled the supply of electrons and sulfur supply through the sulfate reduction pathway more in the mutant relative to the wildtype, independent of rate. We conclude that the smaller fractionation observed in the mutant strain is a consequence of sulfate reduction that proceeded at a rate that consumed a greater proportion of the strains overall capacity for sulfate reduction. These observations have consequences for models of sulfate reducer metabolism and how it yields different isotopic fractionations, notably, the role of DsrC in central energy metabolism.
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Affiliation(s)
- William D. Leavitt
- Department of Earth Sciences, Dartmouth College, Hanover, NH, United States
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States
- Department of Chemistry, Dartmouth College, Hanover, NH, United States
| | - Sofia S. Venceslau
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Jacob Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, United States
| | - Derek A. Smith
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States
| | - Inês A. Cardoso Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Alexander S. Bradley
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, United States
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, United States
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Sim MS, Ogata H, Lubitz W, Adkins JF, Sessions AL, Orphan VJ, McGlynn SE. Role of APS reductase in biogeochemical sulfur isotope fractionation. Nat Commun 2019; 10:44. [PMID: 30626879 PMCID: PMC6327049 DOI: 10.1038/s41467-018-07878-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/29/2018] [Indexed: 11/09/2022] Open
Abstract
Sulfur isotope fractionation resulting from microbial sulfate reduction (MSR) provides some of the earliest evidence of life, and secular variations in fractionation values reflect changes in biogeochemical cycles. Here we determine the sulfur isotope effect of the enzyme adenosine phosphosulfate reductase (Apr), which is present in all known organisms conducting MSR and catalyzes the first reductive step in the pathway and reinterpret the sedimentary sulfur isotope record over geological time. Small fractionations may be attributed to low sulfate concentrations and/or high respiration rates, whereas fractionations greater than that of Apr require a low chemical potential at that metabolic step. Since Archean sediments lack fractionation exceeding the Apr value of 20‰, they are indicative of sulfate reducers having had access to ample electron donors to drive their metabolisms. Large fractionations in post-Archean sediments are congruent with a decline of favorable electron donors as aerobic and other high potential metabolic competitors evolved.
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Affiliation(s)
- Min Sub Sim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, South Korea. .,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA.
| | - Hideaki Ogata
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany.,Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany
| | - Jess F Adkins
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Alex L Sessions
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Shawn E McGlynn
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA. .,Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Tokyo, 152-8550, Japan.
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Pellerin A, Wenk CB, Halevy I, Wing BA. Sulfur Isotope Fractionation by Sulfate-Reducing Microbes Can Reflect Past Physiology. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:4013-4022. [PMID: 29505248 DOI: 10.1021/acs.est.7b05119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Sulfur (S) isotope fractionation by sulfate-reducing microorganisms is a direct manifestation of their respiratory metabolism. This fractionation is apparent in the substrate (sulfate) and waste (sulfide) produced. The sulfate-reducing metabolism responds to variability in the local environment, with the response determined by the underlying genotype, resulting in the expression of an "isotope phenotype". Sulfur isotope phenotypes have been used as a diagnostic tool for the metabolic activity of sulfate-reducing microorganisms in the environment. Our experiments with Desulfovibrio vulgaris Hildenborough (DvH) grown in batch culture suggest that the S isotope phenotype of sulfate respiring microbes may lag environmental changes on time scales that are longer than generational. When inocula from different phases of growth are assayed under the same environmental conditions, we observed that DvH exhibited different net apparent fractionations of up to -9‰. The magnitude of fractionation was weakly correlated with physiological parameters but was strongly correlated to the age of the initial inoculum. The S isotope fractionation observed between sulfate and sulfide showed a positive correlation with respiration rate, contradicting the well-described negative dependence of fractionation on respiration rate. Quantitative modeling of S isotope fractionation shows that either a large increase (≈50×) in the abundance of sulfate adenylyl transferase (Sat) or a smaller increase in sulfate transport proteins (≈2×) is sufficient to account for the change in fractionation associated with past physiology. Temporal transcriptomic studies with DvH imply that expression of sulfate permeases doubles over the transition from early exponential to early stationary phase, lending support to the transport hypothesis proposed here. As it is apparently maintained for multiple generations (≈1-6) of subsequent growth in the assay environment, we suggest that this fractionation effect acts as a sort of isotopic "memory" of a previous physiological and environmental state. Whatever its root cause, this physiological hysteresis effect can explain variations in fractionations observed in many environments. It may also enable new insights into life at energetic limits, especially if its historical footprint extends deeper than generational.
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Affiliation(s)
- André Pellerin
- Center for Geomicrobiology, Department of Bioscience , Aarhus University , Ny Munkegade 114 , Aarhus C 8000 , Denmark
| | - Christine B Wenk
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Itay Halevy
- Department of Earth and Planetary Sciences , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Boswell A Wing
- Geological Sciences , University of Colorado Boulder , UCB 399, Boulder , Colorado 80309-0399 , United States
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Feng Y, Stams AJM, de Vos WM, Sánchez-Andrea I. Enrichment of sulfidogenic bacteria from the human intestinal tract. FEMS Microbiol Lett 2017; 364:2966324. [PMID: 28158432 DOI: 10.1093/femsle/fnx028] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 01/30/2017] [Indexed: 01/16/2023] Open
Abstract
Hydrogen sulfide is formed in the human intestinal tract as the end product of the anaerobic microbial degradation of sulfur compounds present in mucus, bile or proteins. Since human gut microbial sulfur metabolism has been poorly characterized, we aimed to identify and isolate the microorganisms involved in sulfide formation. Fresh fecal samples from one healthy donor and one diagnosed with irritable bowel syndrome were used as inocula for enrichments that were supplemented with sulfate or sulfite as electron acceptors in combination with different electron donors. After two transfers, cultures with high sulfide production were selected and the phylogenetic composition of the enriched microbial communities was determined. Sulfite respiration and cysteine degradation were the dominant sulfidogenic processes, and the most abundant bacteria enriched belonged to Bilophila and Clostridium cluster XIVa. Different isolates were obtained and remarkably included a novel sulfite reducer, designated strain 2C. Strain 2C belongs to the Veillonellaceae family of Firmicutes phylum and showed limited (91%) 16S rRNA gene sequence similarity with that of known Sporomusa species and hence may represent a novel genus. This study indicates that bacteria that utilize sulfite and organic sulfur compounds rather than merely sulfate are relevant for human intestinal sulfur metabolism.
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Affiliation(s)
- Yuan Feng
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands.,IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands.,Department of Bacteriology and Immunology, Faculty of Medicine University of Helsinki, 00014 Helsinki, Finland
| | - Irene Sánchez-Andrea
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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Zaarur S, Wang DT, Ono S, Bosak T. Influence of Phosphorus and Cell Geometry on the Fractionation of Sulfur Isotopes by Several Species of Desulfovibrio during Microbial Sulfate Reduction. Front Microbiol 2017; 8:890. [PMID: 28611734 PMCID: PMC5447228 DOI: 10.3389/fmicb.2017.00890] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/02/2017] [Indexed: 12/02/2022] Open
Abstract
We investigated the influence of organic substrates and phosphate concentration on the rates of dissimilatory microbial sulfate reduction and the 34S/32S isotopic fractionation produced by several Desulfovibrio species. Our experiments corroborate the previously reported species-specific correlation between sulfur isotope fractionation and cell-specific sulfate reduction rates. We also identify cell size as a key factor that contributes to the species-effect of this correlation. Phosphate limitation results in larger cells and contributes to a small decrease in sulfur isotope fractionation concomitant with an apparent increase in cell-specific sulfate reduction rates. Sulfur isotope fractionation in phosphate-limited cultures asymptotically approaches a lower limit of approximately 5‰ as cell-specific sulfate reduction rates increase to >100 fmol cell−1 day−1. These experimental results test models that link the reversibilities of enzymatic steps in dissimilatory sulfate reduction to sulfur isotope fractionation and show that these models can provide consistent predictions across large variations in physiological states experienced by sulfate reducing bacteria.
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Affiliation(s)
- Shikma Zaarur
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of TechnologyCambridge, MA, United States
| | - David T Wang
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of TechnologyCambridge, MA, United States
| | - Shuhei Ono
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of TechnologyCambridge, MA, United States
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of TechnologyCambridge, MA, United States
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