Methanogenic Diversity in an Anaerobic Digester with Chicken Feces

Abstract:

Methanogenic diversity was characterized in an anaerobic digester with chicken feces by using a culture-independent approach. 50 clones of a 16S rDNA gene library were randomly selected and their sequences were phylogenetically analyzed. 46 of them (92%) was determined belonging to Methanogenium with similarities to Methanogenium marinum strain AK-1 between 99% to 100%; 3 clones (6%), KD525, KD526, and KD567, belonging to Methanoculleus with similarities 99% to Methanoculleus sp. dm2; one clone (2%), KD519, belonging to Methanocorpusculum with a similarity 99% to Methanocorpusculum bavaricum. Further more, the phylogenetic analyse of alpha subunit A of methyl-coenzyme M reductase (mcrA) clones were also performed. Gas chromatography assay showed that the content of formic acid was 28.85 g/L, 81.7% of the total volatile fatty acid of the fresh fermentation slurry; and the produced biogas from the digester was also determined, mainly composing of methane (55.5%), carbon dioxide (41.1%), and hydrogen (3.2%).