[Degradation of fatty acid by syntrophic hydrocarbon-degrading consortium M82].

OBJECTIVE

Using molecular ecology methods, we screened non-hydrocarbon carbon sources suitable for growth of syntrophic hydrocarbon-degrading Syntrophus sp.

METHODS

The acclimated methanogenic hexadecane-degrading consortium M82 was subcultured with dodecanedioic acid, tetradecanedioic acid, hexadecanoic acid, propionate and lactate. PCR-DGGE and qPCR were used to analyze the abundance and quantity of syntrophaceae using different carbon sources. The T-RFLP was applied to analyze archaeal community.

RESULTS

The consortium M82 could grow and produce methane using a variety of fatty acids that also resulted in the change in bacterial microbial community structure. Syntrophaceae bacterial stripe was obviously detected in the culture added additional dodecanedioic acid and tetradecanedioic acid. Furthermore, the results show that the logarithmic abundance of Syntrophaceae was 7.4 and 7.6 in per milliliter culture in the two enrichment cultures respectively, which were 2 - 3 units higher than these in other cultures. The archaeal community structure was mainly composed of acetoclastic methanogens Methanosaeta and hydrogenotrophic methanogens Methanoculleus in all culture.

CONCLUSION

Syntrophus sp. can use non-hydrocarbon carbon source (dodecanedioic acid and tetradecanedioic acid) as substrate to grow, which provides valuable information to isolate syntrophic hydrocarbon bacteria, and reveal the molecular mechanism of syntrophic hydrocarbon degradation.