Bacterial cultures capable of facultative growth on methane under thermophilic or thermotolerant conditions. Issue 6 (1st November 2007) - Niedzielski, Maksymilian F
Abstract : Bacteria cultured from thermal features (cultures OS and 44) and from sedimentary rock of the continental margin (SA) are capable of growth on methane as a sole carbon source under thermotolerant (OS and 44) to thermophilic (SA) conditions. All three grew better on enriched medium, suggesting methane is not a preferred substrate. Sequencing (16S rDNA) suggests OS and 44 are primarily Brevibacillus and SA is primarily Geobacillus, not members of described methanotrophic genera. These cultures appear pure based on cell morphology, however they may be consortia of tightly syntrophic bacteria. Growth on 13 C-methane demonstrated that these bacteria incorporate carbon from methane. Labeling (δ 13 C) was greatest when cultures were grown on methane only. When medium was supplemented with yeast extract (0.05%) labeling was less intense, however total methane incorporation was greater due to increased bacterial biomass. These bacterial cultures could have application for methane removal from waste streams at high temperatures.