Effect of heavy ions on the activation of methanogenic bacteria

A mixed culture of methanogenic bacteria was grown on different types of culture media. The activity of the methanogenic culture was compared by the production of bio-gas [methane] from buffalo dung with respect to time. For this purpose culture propagated on media containing different nutrients were allowed to ferment buffalo dung at 35°C. Heavy metal ions, Zn, Mn, Co, Cu, Ni, Mo were applied at the concentration of 10 ppm. These metal ions were applied singly and in different combinations along with a specific culture medium. The results have shown that the culture produced by the media containing Zn, Mn, Co, Cu, Ni, Mo salts are much more active than those produced by culture medium without these elements