Molecular characterization of bacterial and archaeal communities in a full-scale anaerobic reactor treating corn straw

A 16S rRNA gene-based method was used to characterize the structure of bacterial and archaeal communities in a full-scale, anaerobic reactor treating corn straw. Degradability experiment indicated biogas slurry had high microbial activity, the TS removal rate was 53% and the specific methanogenic activity was 86 mL CH4 g VSS−1 d−1. During anaerobic degradation of corn straw, volatile acids and aromatic compounds (p-cresol, phenylpropionate, phenol and benzoate) were detected as transient intermediates. Phylogenetic analysis revealed bacterial community exhibited high diversity, 69 bacterial phylotypes in 13 phyla were identified. Firmicutes (48.3%), Chloroflexi (20.1%), Actinobacteria (9.1%), Bacteroidetes (7.7%), and Proteobacteria (7.2%) represented the most abundant bacterial phyla. Hydrolytic and fermentative bacteria were major bacterial populations. Moreover, a relatively high proportion of syntrophic propionate and aromatic compounds degrading bacteria were detected. In the archaeal clone library, 11 archaeal phylotypes affiliated with two phyla of Crenarchaeota (10%) and Euryarchaeota (90%) were identified.