Isolation, identification and characterisation of butyric acid degrading bacterium from pit latrine faecal sludge

Abstract

Butyric acid is one of the volatile organic compounds that contribute significantly to pit latrine offensive smell. The objective of this work was to isolate, identify and characterize pure butyric acid-utilising bacteria from enriched mixed cultures. A bacterial strain capable of utilising butyric acid as a sole carbon source was isolated from the pit latrine faecal sludge. Based on the 16 Subunit ribosomal Ribo-Nucleic Acid (16S rRNA) analysis, the strain was identified as Pseudomonas aeruginosa. The strain has the capability to utilise 1000 mg/Land 5000 mg/L of butyric acid in 27 h and 42 h, respectively. Further experiments showed that its cell growth was optimal at pH 7 when incubated at 30 oC and 150 rpm. The bacterial strain utilises butyric acid even in the presence of paracresol. The isolation of the strain from indigenous pit latrine faecal sludge showed that there is significant potential for application of microbes in treating noxious smells from the pit latrines.