Detection and survival of pathogens during two-stage thermophilic/mesophilic anaerobic treatment of suspended organic waste

The food-borne pathogens Salmonella typhimurium and Listeria monocytogenes were effectively eliminated from suspended organic waste during the thermophilic (55°C) phase of a two-stage thermophilic/mesophilic anaerobic reactor. The feasibility of PCR technology was evaluated in order to improve the speed of detection and reduce the effort involved in detecting the presence of a range of pathogenic bacteria. Our results show direct extraction of nucleic acids followed by purification and PCR to be a promising method that will enable the rapid verification of hygienic performance during waste treatment.