Transition of microbial communities during the adaption to anaerobic digestion of carrot waste

In this study a microbial community suitable for anaerobic digestion of carrot pomace was developed from inocula obtained from natural environmental sources. The changes along the process were monitored using pyrosequencing of the 16S rRNA gene. As the community adapted from a diverse natural community to a community with a definite function, diversity decreased drastically. Major bacterial groups remaining after enrichment were Bacilli (31–45.3%), Porphyromonadaceae (12.1–24.8%) and Spirochaetes (12.5–18.5%). The archaeal population was even less diverse and mainly represented by a single OTU that was 99.7% similar to Methanosarcina mazei. One enrichment which failed to produce large amounts of methane had shifts in the bacterial populations and loss of methanogenic archaea.