Title: Microbial Study on Cow Dung from Guinea/Gamba Grass Based Diet at Different Temperatures Used for Biogas Production
Authors: Orlando Ketebu
Volume: 1
Issue: 9
Pages: 4-10
Publication Date: 2017/11/28
Abstract:
Biogas production from agricultural waste has numerous benefits such as source of revenue to countries developing it, reduction of environmental pollution and greenhouse effect, alternative source of energy and source of generating employment to reduce youth restiveness in developing countries such as Nigeria. Biogas production from different agricultural waste has been studied but less research has focussed on analysing the bacterial communities responsible for the biogas production on the different agricultural substrate used for biogas production. This paper looks at the microbial community responsible for biogas production from cow dung obtained Fulani cattle fed on guinea /gamba grass base diet at 30 OC, 32 OC, 35 OC, 37 OC and 38 OC. The experimental result from the microbial analysis of the waste showed that 37oC and 35OC had higher microbial isolates, with 37having the highest Too Numerous To Count (TNTC) values compared to 35 OC. At 37 OC, 1.27 x 1010 colony forming unit per gram (cfu/g) was obtained after 24 hours and 5.6 x 109 cfu/g was obtained at 35 OC. The genera of acetogenic bacteria and methanogens responsible for biogas production at these temperatures were identified as acetobacterium woodii and Methanobrevibacteria ruminantium . Other bacteria’s found at these temperature are the Staplylococcus species and Escherichia specie which also aided the formation of biogas at these temperature. The same methanogens and acetogenic bacteria’s were observed at 38 OC and 32 OCbut none was observed when the waste was cultured and analysed at 30 OC. The result also showed that moulds and yeast where found on the cow dung waste analysed at 30oC which greatly affected the biogas production at this temperature. In general biogas production from cow dung obtained from cattle fed on guinea/gamba grass feed was more favourable at 37 OC followed by 35 OC as corroborated by the microbial analysis.