@article {420,
	title = {Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers.},
	journal = {Appl Environ Microbiol},
	volume = {77},
	year = {2011},
	month = {2011 Sep},
	pages = {6502-9},
	abstract = {Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that the transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate-reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a decline in dsrB transcript abundance in the Desulfobacteraceae. These results suggest that monitoring transcripts of dissimilatory (bi)sulfite reductase genes in distinct populations of sulfate reducers can provide insight into the relative rates of metabolism of different components of the sulfate-reducing community and their ability to respond to environmental perturbations.},
	keywords = {Biodiversity, Deltaproteobacteria, DNA, Bacterial, Gene Expression Profiling, Hydrogensulfite Reductase, Molecular Sequence Data, Oxidation-Reduction, Sequence Analysis, DNA, Soil Microbiology, Sulfates, Water Microbiology},
	issn = {1098-5336},
	doi = {10.1128/AEM.00576-11},
	author = {Miletto, M and Williams, K H and N{\textquoteright}Guessan, A L and Lovley, D R}
}
@article {474,
	title = {Quantification of Desulfovibrio vulgaris dissimilatory sulfite reductase gene expression during electron donor- and electron acceptor-limited growth.},
	journal = {Appl Environ Microbiol},
	volume = {74},
	year = {2008},
	month = {2008 Sep},
	pages = {5850-3},
	abstract = {Previous studies have suggested that levels of transcripts for dsrA, a gene encoding a subunit of the dissimilatory sulfite reductase, are not directly related to the rates of sulfate reduction in sediments under all conditions. This phenomenon was further investigated with chemostat-grown Desulfovibrio vulgaris. Under sulfate-limiting conditions, dsrA transcript levels increased as the bulk rates of sulfate reduction in the chemostat increased, but transcript levels were similar at all sulfate reduction rates under electron donor-limiting conditions. When both electron donor- and electron acceptor-limiting conditions were considered, there was a direct correspondence between dsrA transcript levels and the rates of sulfate reduction per cell. These results suggest that dsrA transcript levels may provide important information on the metabolic state of sulfate reducers.},
	keywords = {Desulfovibrio vulgaris, Electron Transport, Gene Expression, Geologic Sediments, Hydrogensulfite Reductase, Oxidation-Reduction, RNA, Bacterial, RNA, Messenger, Sulfates},
	issn = {1098-5336},
	doi = {10.1128/AEM.00399-08},
	author = {Villanueva, Laura and Haveman, Shelley A and Summers, Zara M and Lovley, Derek R}
}
@article {500,
	title = {Quantifying expression of a dissimilatory (bi)sulfite reductase gene in petroleum-contaminated marine harbor sediments.},
	journal = {Microb Ecol},
	volume = {55},
	year = {2008},
	month = {2008 Apr},
	pages = {489-99},
	abstract = {The possibility of quantifying in situ levels of transcripts for dissimilatory (bi)sulfite reductase (dsr) genes to track the activity of sulfate-reducing microorganisms in petroleum-contaminated marine harbor sediments was evaluated. Phylogenetic analysis of the cDNA generated from mRNA for a ca. 1.4 kbp portion of the contiguous dsrA and dsrB genes suggested that Desulfosarcina species, closely related to cultures known to anaerobically oxidize aromatic hydrocarbons, were active sulfate reducers in the sediments. The levels of dsrA transcripts (per mug total mRNA) were quantified in sediments incubated anaerobically at the in situ temperature as well as in sediments incubated at higher temperatures and/or with added acetate to increase the rate of sulfate reduction. Levels of dsrA transcripts were low when there was no sulfate reduction because the sediments were depleted of sulfate or if sulfate reduction was inhibited with added molybdate. There was a direct correlation between dsrA transcript levels and rates of sulfate reduction when sulfate was at ca. 10 mM in the various sediment treatments, but it was also apparent that within a given sediment, dsrA levels increased over time as long as sulfate was available, even when sulfate reduction rates did not increase. These results suggest that phylogenetic analysis of dsr transcript sequences may provide insight into the active sulfate reducers in marine sediments and that quantifying levels of dsrA transcripts can indicate whether sulfate reducers are active in particular sediment. Furthermore, it may only be possible to use dsrA transcript levels to compare the relative rates of sulfate reduction in sediments when sulfate concentrations, and possibly other environmental conditions, are comparable.},
	keywords = {Anaerobiosis, Desulfitobacterium, DNA, Bacterial, DNA, Ribosomal, Gene Expression, Geologic Sediments, Hydrogensulfite Reductase, Molecular Sequence Data, Petroleum, Phylogeny, RNA, Bacterial, RNA, Messenger, RNA, Ribosomal, 16S, Temperature},
	issn = {0095-3628},
	doi = {10.1007/s00248-007-9294-2},
	author = {Chin, Kuk-Jeong and Sharma, Manju L and Russell, Lyndsey A and O{\textquoteright}Neill, Kathleen R and Lovley, Derek R}
}
