The effect of anaerobic digestion on the survival of salmonella and coliform bacteria

Abstract

The decline in viable number of salmonella and coliform bacteria was investigated in laboratory based anaerobic and aerobic digesters using cow dung. The results indicated that unheated anaerobic digestion had greater reduction in the viable number of salmonella and coliform bacteria 1.05x10⁴ and 1.26 x 10⁴ cells/ml respectively than the aerobic digestion 4.50x10⁶ and 1.58x10⁶ cells/ml respectively. The anaerobic and aerobic digestions were found to be temperature dependent. Decrease in temperature from 31±1oC to 26±1oC resulted in increase in viable cell count in the digestions. The final pH was found to be 8.10 in the unheated anaerobic digestion. The reduction of Salmonella spp to 1.05 x 10⁴cells/ml showed that anaerobic digestion could help in combating the spread of infectious diseases on farmland and hospitals.

Keywords: Salmonella spp, bacteria, cow dung, anaerobic and aerobic digestions

International Journal of Natural and Applied Sciences, 6(3): 359-362, 2010