抄録
The anaerobic long-chain fatty acids (LCFA) degrading microorganisms were enriched and attempted at isolation of those microbes to address the fundamental information of microbes responsible for anaerobic degradation of LCFA. Primary enrichment cultures were made with each of four LCFA substrates (palmitate, stearate, oleate and linoleate as a sole energy source) at 55°C or 37°C with two sources of anaerobic granular sludge as the inoculum. After several successive transfers of these enrichments, we applied 16S rRNA gene-based molecular approaches for the enrichments to reveal the bacterial populations reside in. These results suggested that anaerobic degradation of LCFA may involve in not only microbes belonging to the family Syntrophomonadaceae, which contains all anaerobic syntrophic LCFA degrader isolated so far, but also phylogenetically different groups of bacteria. After several attempts were made to isolate these microbes, we obtained a highly purified culture which was able to degrade palmitate in syntrophic association with hydrogenotrophic methanogens from the thermophilic palmitate-degrading enrichment culture. In addition, we successfully isolated strain TOL which was predominant population in the thermophilic oleate-degrading enrichment culture. However, strain TOL did not show oleate degradability under any cultivation conditions to date.
