Identification of bacteria involved in the decomposition of lignocellulosic biomass treated with cow rumen fluid by metagenomic analysis

Abstract

<jats:title>Abstract</jats:title><jats:p>Previously, pretreatment of plant biomass using rumen fluid systems was developed to decompose cell wall. However, microbes which involved in plant cell wall decomposition in this system have not been identified, because the conditions of this system are different from the <jats:italic>in situ</jats:italic> rumen environment. We investigated the bacteria involved in the decomposition of cellulose and hemicellulose in a waste paper with the rumen pretreatment system using shotgun metagenomic analysis with next generation sequencing. After pretreatment of waste paper, about a half of the cellulose and hemicellulose content was decomposed. Genes encoding for cellulase and hemicellulase were mainly found to belonging to <jats:italic>Ruminococcus, Clostridium</jats:italic>, and <jats:italic>Exiguobacterium</jats:italic>. This study shows that <jats:italic>Clostridium</jats:italic> and <jats:italic>Exiguobacterium</jats:italic>, which have not been identified as predominant genus involved in cellulose and hemicellulose decomposition, might be categorized as the main fibrolytic bacteria in this system.</jats:p>

Effect of Heat Stress on Rumen Microbial Diversity and Fermentation Pattern in Buffalo

“…Similar results were also reported in cattle [19,25] and goats [27]; however, in the present study, a few bacteria taxa which existed during thermoneutral conditions were not detected, and few bacteria taxa were detected after exposure to heat stress. In the present study, the order of abundance of the three major phyla in the rumen bacterial population was Firmicutes, Bacteroidetes, and Proteobacteria, which were in agreement with the rumen microbial abundance in other species like goats [27,46,47] and cattle [12,19,24,25,48]. On the contrary, the abundance of Bacteroidetes was reported to be higher than Firmicutes in cattle [21,49,50] and lambs [51].…”