Community structure of microbial consortia enriched on halogenated aromatic compounds under different electron accepting conditions

V.K. Knight, L.J. Kerkhof, and M.M. Häggblom

Biotechnology Center for Agriculture and the Environment

Rutgers, The State University of New Jersey

59 Dudley Road, New Brunswick, NJ 08901-8520, USA

Phospholipid fatty acid analysis (PFLA) can be used as a rapid method to monitor changes in microbial community structure. In addition, microorganisms in consortia can be identified by direct isolation of DNA followed by construction of 16S rDNA clonal libraries and sequencing of unique clones. Combined these two approaches provide more detailed information about the entire microbial community. Dehalogenating microbial consortia were enriched under sulfidogenic, Fe(III)-reducing or methanogenic conditions using a common sediment inoculum with brominated phenols and benzoic acids as the a carbon source. Stable consortia were maintained with repeated feeding and serial dilution into fresh medium. Microbial communities were monitored by PFLA analysis and phylogenetic techniques. Principal component analysis of the phospholipid fatty acids demonstrated that distinct populations were enriched with each substrate and under each electron accepting condition. The combination of PFLA and phylogenetic analysis will help discern the organisms responsible for dehalogenation and degradation of halogenated aromatic compounds under different reducing conditions.