Screening Escherichia coli, Enterococcus faecalis, and Clostridium perfringens as indicator organisms in evaluating pathogen-reducing capacity in biogas plants.

This study was conducted to identify an indicator organism(s) in evaluating the pathogen-reducing capacity of biogas plants. Fresh cow manure containing 10(4) to 10(5) colony forming unit (CFU) per milliliter of Escherichia coli and Enterococcus faecalis along with an inoculated Clostridium perfringens strain were exposed to 37 degrees C for 15 days, 55 degrees C for 48 h, and 70 degrees C for 24 h. C.