HR: 1400h
AN: B13B-05 [Abstracts]
TI: Sulfur Isotopic Fractionation During Dissimilatory Sulfate Reduction from the Perspective of an Entire Microbial Metabolism
AU: * Webber, B
EM: benjamin.webber@mail.mcgill.ca
AF: McGill University, 805 rue Sherbrooke O., Montréal, QC H3A 2A7, Canada
AU: Lau, L
EM: lawrence.lau2@mail.mcgill.ca
AF: McGill University, 805 rue Sherbrooke O., Montréal, QC H3A 2A7, Canada
AU: Wing, B
EM: boswell.wing@mcgill.ca
AF: McGill University, 805 rue Sherbrooke O., Montréal, QC H3A 2A7, Canada
AB:
Whether in the investigation of the most ancient life on Earth, examination of surface oxidation properties
across geological timescales, or the estimation of microbial metabolism in inaccessible environments,
dissimilatory sulfate reduction (DSR) constrains biogeochemical processes in a variety of spatial and temporal
scales.
Pioneering work in the 1970s established the importance of DSR to biogeochemical processes and its
potential as a geochemical tracer, and models for biological controls of DSR were published from empirical
results of in vitro microbial cultures. Recent efforts have expanded upon this body of work and further extended
toward multiple sulfur isotopes and through the more precise definition of the biological processes
themselves. Resulting from these recent efforts is an rigorous description of DSR of the sulfur metabolism of
sulfate-reducing bacteria.
However, despite these efforts, the exact mechanisms of DSR within the scope of a complex system such as
microbial metabolism remain incomplete and obscure. We will be presenting ongoing work coupling together
recent mathematical models of isotopic fractionation with a flux-oriented, genomically-derived software model
of the metabolism of Desulfovibrio vulgaris, a patent sulfate-reducing bacterium. Our presentation will explore
the effects on isotopic fractionation throughout the sulfate reduction pathway of D. vulgaris by a multitude of
separate and distinct biological pathways within the bacterial metabolism. Further, we will be discussing both
the pitfalls and promise of such an approach and its implications for future research.
DE: 0420 Biomolecular and chemical tracers
DE: 0465 Microbiology: ecology, physiology and genomics (4840)
DE: 0466 Modeling
DE: 0488 Sulfur cycling
SC: Biogeosciences [B]
MN: 2009 Joint Assembly