Microbial Dynamics during Anaerobic Digestion of Cow Dung

The anaerobic digestion of cow dung was investigated for 30days in a laboratory scale batch reactor. Totally nine bacterial strains were isolated from cow dung slurry. The bacterial isolates were preliminarily examined by morphological characteristics and they were further confirmed by 16S rRNA sequencing and analyzed through BLAST. Microbial dynamics showed that hydrolytic bacterial population was initially increased and decreased towards the end of anaerobic digestion. But in methanogenic population, they were initially very low and increased gradually towards the end of anaerobic digestion. In Ruminococcus species the population was observed in fluctuation. The total solid (TS), volatile solid (VS) and chemical oxygen demand (COD) removals amounted to 46.12%, 43.14% and 45.23% respectively. Anaerobic digestion was feasible with pH about 7.17, temperature at 37.18C and maximum methane yield was about 64% at 30 day of digestion.