Project description:We established simple synthetic microbial communities in a microcosm model system to determine the mechanisms that underlay cross-feeding in microbial methane-consuming communities. Co-occurring strains from Lake Washington sediment were used that are involved in methane consumption, a methanotroph and two non-methanotrophic methylotrophs. Overall design: RNAseq profiles of methanotrophs and non-methanotrophic methylotrophs in pure culture and in two species mixtures. Duplicate samples (total N = 10) were submitted for transcriptomics analysis to GENEWIZ (Seattle, USA). 1 x 50 bp were sequenced in single-read configuration in Rapid Run mode on a HiSeq 2500 System.
Project description:Harnessing the metabolic potential of uncultured microbial communities is a compelling opportunity for the biotechnology industry, an approach that would vastly expand the portfolio of usable feedstocks. Methane is particularly promising because it is abundant and energy-rich, yet the most efficient methane-activating metabolic pathways involve mixed communities of anaerobic methanotrophic archaea and sulfate reducing bacteria. These communities oxidize methane at high catabolic efficiency and produce chemically reduced by-products at a comparable rate and in near-stoichiometric proportion to methane consumption. These reduced compounds can be used for feedstock and downstream chemical production, and at the production rates observed in situ they are an appealing, cost-effective prospect. Notably, the microbial constituents responsible for this bioconversion are most prominent in select deep-sea sediments, and while they can be kept active at surface pressures, they have not yet been cultured in the lab. In an industrial capacity, deep-sea sediments could be periodically recovered and replenished, but the associated technical challenges and substantial costs make this an untenable approach for full-scale operations. In this study, we present a novel method for incorporating methanotrophic communities into bioindustrial processes through abstraction onto low mass, easily transportable carbon cloth artificial substrates. Using Gulf of Mexico methane seep sediment as inoculum, optimal physicochemical parameters were established for methane-oxidizing, sulfide-generating mesocosm incubations. Metabolic activity required >?40% seawater salinity, peaking at 100% salinity and 35?°C. Microbial communities were successfully transferred to a carbon cloth substrate, and rates of methane-dependent sulfide production increased more than threefold per unit volume. Phylogenetic analyses indicated that carbon cloth-based communities were substantially streamlined and were dominated by Desulfotomaculum geothermicum. Fluorescence in situ hybridization microscopy with carbon cloth fibers revealed a novel spatial arrangement of anaerobic methanotrophs and sulfate reducing bacteria suggestive of an electronic coupling enabled by the artificial substrate. This system: 1) enables a more targeted manipulation of methane-activating microbial communities using a low-mass and sediment-free substrate; 2) holds promise for the simultaneous consumption of a strong greenhouse gas and the generation of usable downstream products; and 3) furthers the broader adoption of uncultured, mixed microbial communities for biotechnological use.
1000-01-01 | S-EPMC5947824 | BioStudies
Project description:EMG produced TPA metagenomics assembly of the Methane-oxidizing microbial communities from mesocosms in the Hudson Canyon - EN1E Hudson Canyon metagenome (sediment metagenome) data set.
| PRJEB26408 | ENA
Project description:EMG produced TPA metagenomics assembly of the Methane-oxidizing microbial communities from mesocosms in the Hudson Canyon - EN8C Hudson Canyon metagenome (sediment metagenome) data set.
| PRJEB26297 | ENA
Project description:EMG produced TPA metagenomics assembly of the Methane-oxidizing microbial communities from mesocosms in the Hudson Canyon - EN8B Hudson Canyon metagenome (sediment metagenome) data set.