Abstract
The industrial and non-industrial nations are both trapped between a rising inhabitants generating substantial amount of waste and the awaiting arrival of hard frontier to non-renewable energy sources. This study was aimed at isolation, identification and characterization of some bacteria associated with biogas generation via anaerobic digestion of cow dung using standard microbiological methods. Fresh cow dung was collected from Lafia abattoir, Nasarawa State, Nigeria. The sample was collected in a 100 g clean plastic container and transported to the laboratory for analysis. The total quantity of biogas produced from the cow dung by anaerobic digestion was 13.180 ml in the fifteenth (15th) day of the digestion period with daily mean production of 878.67 ml. The least volume of about 700 ml was produced in the second day of digestion period. The total aerobic and anaerobic bacteria count ranged from 6.3×〖10〗^7 to 2.5×〖10〗^8 and 1.8×〖10〗^7 to 2.3×〖10〗^7 cfu⁄ml, respectively. The microorganisms isolated from the digester before, during and after anaerobic digestion include Escherichia coli, Bacillus sp., Pseudomonas sp., Staphylococcus sp., and Proteus sp. The results revealed that the generation of biogas from cow dung is potentially a good, cheap and alternative source of fuel or energy. The biogas technology is a good way of providing solution to the increasing waste management and disposal problems apart from the generation of fuel or energy from renewable energy sources.

Key words: Cow dung, Biogas, Anaerobic digestion, Renewable energy, Waste management