Microbial 16S rDNA diversity in an anaerobic digester

Abstract

The bacterial community structure of a fluidized bed reactor fed by vinasses was analysed by molecular identification. After PCR amplification, three 16S rDNA clone libraries of Bacteria, Archaea, and Procarya populations were established. Community structure was determined by phylogenetic analysis of 556 partial rDNA sequences (about 500 bp long). 139 OTUs (Operational Taxonomic Unit) were found among which 133 and 6 were from the Bacteria and Archaea domains respectively. The majority of bacterial OTUs are not closely related to all other hitherto-determined sequences. The ratio Archaea/Bacteria is 1/4 and the most frequent bacterial OTU represents less than 5% of the characterised bacterial population.