论文部分内容阅读
Promoting direct interspecies electron transfer(DIET)to enhance syntrophic metabolism may be a strategy for accelerating and stabilizing the conversion of organic wastes to methane,but microorganisms capable of metabolizing key intermediates,such as propionate and butyrate,via DIET under methanogenic conditions have yet to be identified.In an attempt to establish methanogenic communities metabolizing propionate or butyrate with DIET,enrichments were initiated with up-flow anaerobic sludge blanket(UASB)reactors,similar to those that were previously reported to support communities that metabolized ethanol with DIET that relied on direct biological electrical connections between the syntrophic partners.In the absence of any amendments,the microbial communities enriched were dominated by microorganisms closely related to pure cultures that are known to metabolize propionate or butyrate to acetate with the production of H2.However,when biochar was added to the reactors there was a substantial enrichment on the biochar surface of 16S rRNA gene sequences closely related to Geobacter and Methanosaeata species known to participate in DIET.A biochar-amended reactor metabolized propionate faster than the biochar-free control reactor and in the reactors fed butyrate acetate metabolism was more efficient in the presence of biochar.