Project description:Gas hydrates, also known as clathrates, are cages of ice-like water crystals encasing gas molecules such as methane (CH4). Despite the global importance of gas hydrates, their microbiomes remain mysterious. Microbial cells are physically associated with hydrates, and the taxonomy of these hydrate-associated microbiomes is distinct from non-hydrate-bearing sites. Global 16S rRNA gene surveys show that members of sub-clade JS-1 of the uncultivated bacterial candidate phylum Atribacteria are the dominant taxa in gas hydrates. The Atribacteria phylogeny is highly diverse, suggesting the potential for wide functional variation and niche specialization. Here, we examined the distribution, phylogeny, and metabolic potential of uncultivated Atribacteria in cold, salty, and high-pressure sediments beneath Hydrate Ridge, off the coast of Oregon, USA, using a combination of 16S rRNA gene amplicon, metagenomic, and metaproteomic analysis. Methods were developed to extract bacterial cellular protein from these sediments, as outlined below. Sample Description Three sediments samples were collected from beneath Hydrate Ridge, off the coast of Oregon, USA. Sediments were cored at ODP site 1244 (44°35.1784´N; 125°7.1902´W; 895 m water depth) on the eastern flank of Hydrate Ridge ~3 km northeast of the southern summit on ODP Leg 204 in 2002 and stored at -80°C at the IODP Gulf Coast Repository. E10H5 sediment is from 68.5 meters below sediment surface interface C1H2 sediment is from 2 meters below sediment surface interface. C3H4 sediment is from 21 meters below sediment surface interface.
Project description:Freshwater environments such as rivers receive effluent discharges from wastewater treatment plants, representing a potential hotspot for antibiotic resistance genes (ARGs). These effluents also contain low levels of different antimicrobials including biocides and antibiotics such as sulfonamides that can be frequently detected in rivers. The impact of such exposure on ARG prevalence and microbial diversity of riverine environment is unknown, so the aim of this study was to investigate the release of a sub-lethal concentration (<4 g L-1) of the sulfonamide compound sulfamethoxazole (SMX) on the river bacterial microbiome using a microflume system. This system was a semi-natural in-vitro microflume using river water (30 L) and sediment, with circulation to mimic river flow. A combination of ‘omics’ approaches were conducted to study the impact of SMX exposure on the microbiomes within the microflumes. Metaproteomics did not show differences in ARGs expression with SMX exposure in water.
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains. 73 samples total. Evaluation of changes in a model community's metatranscriptome over time after exposure to a consortium of 5 fermented milk product (FMP) strains (40 samples); evaluation of the gene expression of the FMP strains in other in vitro conditions, including MRS medium (B. animalis subsp. lactis only, 4 samples) and a commercial FMP fermentation (all 5 strains, 6 samples); evaluation of the gene expression of native human microbiomes before and after the consumption of a commercial FMP (23 samples).