Efficience of Sulphite-reducing bacteria as sanitary-indicator for water. MPN-Method

Abstract

The possibility of pathogenic virus and protozoa persistence in water submited to purification and desinfection for controlling bacteria, has prompted the look for new water quality indicators. Anaerobic sporulated sulphite-reducing (ASR) bacteria have been described as indicators of sanitary water quality as an alternative to the traditional coliforms in chloride treated potable water.

Thus, the aim of the present work was to test the multiple tube technique for the detection of ASR on DRCM media in water naturally contaminated with fecal residues and its resistance was compared with total coliforms (TC) and fecal coliforms (FC) at 0.1 and 1 mg/kg of chloride as water disinfectant.

Results shows that the MPN methods using DRCM media as selective broth, is efficient and that they show a greater Cl- resistence as TC and FC. Therfore, the use of ASR as sanitary indicator of water is recomended in the presence of resistent biological agents hazard.