ISOLATION OF PROPIONATE DEGRADING BACTERIUM IN COCULTURE WITH A METHANOGEN FROM A CATTLE DUNG BIOGAS PLANT

Various anaerobic hydrolytic and methanogenic bacteria active in cattl e dung biogas plants are reported in the literature. Anaerobic bacteri a with ability to use volatile fatty acids constitute a vital bridge b etween hydrolytic bacteria and methanogenic bacteria. The present pape r describes the isolation of Syntrophobacter wolinii a propionate degr ading bacterium in co-culture with a hydrogen utilizing methanogen viz ., Methanobacterium formicicum from the fermenting slurry of cattle du ng biogas plant. Earlier studies on propionate and butyrate degradatio n indicated Methanospirillum hungatei as the hydrogen utilizing partne r of the co-culture whereas in the present studies this was not the ca se. Temperature 35-degrees-C, pH 7-5 and 20 mM of propionate were foun d optimal for growth and activity of co-culture.