Browsing by Author "Camilleri, Laura B."

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Biofilm growth mode promotes maximum carrying capacity and community stability during product inhibition syntrophy
(2014-12) Brileya, Kristen A.; Camilleri, Laura B.; Zane, Grant M.; Wall, Judy D.; Fields, Matthew W.
Sulfate-reducing bacteria (SRB) can interact syntrophically with other community members in the absence of sulfate, and interactions with hydrogen-consuming methanogens are beneficial when these archaea consume potentially inhibitory H2 produced by the SRB. A dual continuous culture approach was used to characterize population structure within a syntrophic biofilm formed by the SRB Desulfovibrio vulgaris Hildenborough and the methanogenic archaeum Methanococcus maripaludis. Under the tested conditions, monocultures of D. vulgaris formed thin, stable biofilms, but monoculture M. maripaludis did not. Microscopy of intact syntrophic biofilm confirmed that D. vulgaris formed a scaffold for the biofilm, while intermediate and steady-state images revealed that M. maripaludis joined the biofilm later, likely in response to H2 produced by the SRB. Close interactions in structured biofilm allowed efficient transfer of H2 to M. maripaludis, and H2 was only detected in cocultures with a mutant SRB that was deficient in biofilm formation (ΔpilA). M. maripaludis produced more carbohydrate (uronic acid, hexose, and pentose) as a monoculture compared to total coculture biofilm, and this suggested an altered carbon flux during syntrophy. The syntrophic biofilm was structured into ridges (∼300 × 50 μm) and models predicted lactate limitation at ∼50 μm biofilm depth. The biofilm had structure that likely facilitated mass transfer of H2 and lactate, yet maximized biomass with a more even population composition (number of each organism) when compared to the bulk-phase community. Total biomass protein was equivalent in lactate-limited and lactate-excess conditions when a biofilm was present, but in the absence of biofilm, total biomass protein was significantly reduced. The results suggest that multispecies biofilms create an environment conducive to resource sharing, resulting in increased biomass retention, or carrying capacity, for cooperative populations.
Complete genome sequence of Pelosinus fermentans JBW45, a member of a remarkably competitive group of Negativicutes in the Firmicutes Phylum
(2015-09) Bowen De León, Kara; Utturkar, S. M.; Camilleri, Laura B.; Elias, Dwayne A.; Arkin, Adam P.; Fields, Matthew W.; Brown, S. D.; Wall, Judy D.
The genome of Pelosinus fermentans JBW45, isolated from a chromium-contaminated site in Hanford, Washington, USA, has been completed with PacBio sequencing. Nine copies of the rRNA gene operon and multiple transposase genes with identical sequences resulted in breaks in the original draft genome and may suggest genomic instability of JBW45.
Draft genome sequence of Pelosinus fermentans JBW45, isolated during in situ stimulation for Cr(VI) reduction
(2012-10) Bowen De León, Kara; Young, Mary Lynn; Camilleri, Laura B.; Brown, S. T.; Skerker, J. M.; Deutschbauer, A. M.; Arkin, Adam P.; Fields, Matthew W.
Pelosinus fermentans JBW45 is an anaerobic, lactate-fermenting bacterium isolated from Cr(VI)-contaminated groundwater at the Hanford Nuclear Reservation 100-H site (Washington) that was collected after stimulation with a polylactate compound. The genome sequence of this organism will provide insight into the metabolic potential of a predominant population during stimulation for metal-reducing conditions.