The electron transfer system of synthrophically grown desulfovibrio vulgaris

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Journal of Bacteriology

DOI:https://doi.org/10.1128/JB.00356-09· OSTI ID:963925

Walker, Christopher ^[1]; He, Zhili ^[2]; Yang, Zamin Koo ^[3]; Ringbauer, Joseph ^[1]; HE, Qiang ^[3]; Zhou, Jizhong ^[2]; Voordouw, Gerrit ^[4]; Wall, Judy ^[5]; Arkin, Adam ^[6]; Hazen, Terry ^[6]; Stolyar, Sergey ^[7]; Stahl, David ^[7]

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1. University of Washington, Seattle
2. University of Oklahoma
3. ORNL
4. University of Calgary, ALberta, Canada
5. University of Missouri, Columbia
6. Lawrence Berkeley National Laboratory (LBNL)
7. University of Washington

Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic coupling between hydrogen producers and consumers is a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent on growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, numerous genes involved in electron transfer and energy generation were upregulated in D. vulgaris compared with their expression in sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn), and the well-characterized high-molecular-weight cytochrome (Hmc) were among the most highly expressed and upregulated genes. Additionally, a predicted operon containing genes involved in lactate transport and oxidation exhibited upregulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd, and Hyn impaired or severely limited syntrophic growth but had little effect on growth via sulfate respiration. These results demonstrate that syntrophic growth and sulfate respiration use largely independent energy generation pathways and imply that to understand microbial processes that sustain nutrient cycling, lifestyles not captured in pure culture must be considered.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 963925
• Journal Information: Journal of Bacteriology, Journal Name: Journal of Bacteriology Journal Issue: 18 Vol. 191; ISSN JOBAAY; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
CARBON CYCLE
CYTOCHROMES
DESULFOVIBRIO
ELECTRON TRANSFER
ELECTRONS
ENERGY RECOVERY
GENES
HYDROGEN
HYDROGEN TRANSFER
HYDROGENASES
LACTATES
MUTATIONS
NUTRIENTS
ORGANIC MATTER
OXIDATION
RESPIRATION
SULFATES