Anaerobic biodegradation of alkanes by enriched consortia under four different reducing conditions.

Enrichments of alkane-degrading microorganisms were established under sulfate-reducing, denitrifying, iron-reducing, and methanogenic conditions using an estuarine sediment. The sulfate-reducing and denitrifying enrichments mineralized [1-14C]hexadecane to 14CO2. Degradation was coupled to sulfate reduction and denitrification, as indicated by the ratios of hexadecane degraded to the electron acceptors reduced. Dependence of hexadecane degradation by the sulfate-reducing enrichments on sulfate reduction was also shown. The results indicate the existence of diverse microbial communities capable of alkane degradation in the sediment studied.