Peptidolytic microbial community of methanogenic reactors from two modified UASBs of brewery industries

Abstract

We studied the peptide-degrading anaerobic communities of methanogenic reactors from two mesophilic full-scale modified upflow anaerobic sludge blanket (UASB) reactors treating brewery wastewater in Colombia. Most probable number (MPN) counts varied between 7.1 x 10 8 and 6.6 x 10 9 bacteria/g volatile suspended solids VSS (Methanogenic Reactor 1) and 7.2 x 10 6 and 6.4 x 10 7 bacteria/g (VSS)(Methanogenic Reactor 2). Metabolites detected in the highest positive MPN dilutions in both reactors were mostly acetate, propionate, isovalerate and, in some cases, negligible concentrations of butyrate.Using the highest positive dilutions of MPN counts, 50 dominant strains were isolated from both reactors, and 12 strains were selected for sequencing their 16S rRNA gene based on their phenotypic characteristics.The small-subunit rRNA gene sequences indicated that these strains were affiliated to the families