Dominance of Methanomicrobium phylotype in methanogen population present in Murrah buffaloes (Bubalus bubalis)

Aims: To study the diversity of rumen methanogens in Murrah buffaloes (Bubalus bubalis) from North India by using 16S rRNA gene libraries obtained from the pooled rumen content from four animals and using suitable software analysis. Methods and Results: Genomic DNA was isolated and PCR was set up by using specific primers. Amplified product was cloned into a suitable vector and the positive clones were selected on the basis of blue-white screening and sequenced. The resulting nucleotide sequences were arranged in the phylogenetic tree. A total of 108 clones were examined, revealing 17 different 16S rRNA gene sequences or phylotypes. Of the 17 phylotypes, 15 (102 of 108 clones) belonged to the genus Methanomicrobium, indicating that the genus Methanomicrobium is the most dominant component of methanogen populations in Murrah buffaloes (Bubalus bubalis) from North India. The largest group of clones (102 clones) was more than 98% similar to Methanomicrobium mobile. BLAST analysis of the rumen contents from individual animals also revealed 17 different phylotypes with a range of 3-10 phylotypes per animal. Conclusion: Methanomicrobium phylotype is the most dominant phylotype of methanogens present in Murrah buffaloes (Bubalus bubalis). Significance and Impact of the Study: Effective strategies can be made to inhibit the growth of Methanomicrobium phylotype to reduce the methane emission from rumen contents and thus help in preventing global warming.