초록
<P><B>Abstract</B></P> <P>This study investigated the effect of rice straw biochar (RSB) on methane production during mainstream large-scale aerobic composting by using high-throughput sequencing and quantitative PCR. A 55-day large-scale aerobic composting experiment under cyclical forced-turning with aeration was conducted with control (CK) and experimental groups (BC), namely, without and with 10% RSB. The methanogen/methanotroph and microbial community of samples were analyzed by <I>mcrA/pmoA</I> and 16S rRNA/internal transcribed spacer region, respectively. The pore methane concentration had a positive relationship with <I>mcrA</I> and <I>mcrA/pmoA</I>. RSB accelerated methane production, which was reflected by an increase in <I>mcrA</I>. The diversity of bacteria and fungi increased by addition of RSB. Addition of RSB contributed to increasing the RAs of <I>Methanobrevibacter</I> and <I>Methylobacterium. Methanobrevibacter</I> was related to CH<SUB>4</SUB> production, and <I>Methylobacterium</I> related to CH<SUB>4</SUB> consumption through the metabolism of methyl material. Thus, the biochar has always increased the diversity of bacteria, including <I>Methanobrevibacter</I> and <I>Methylobacterium</I>. The optimal way to control CH<SUB>4</SUB> production is to reduce the number of <I>mcrA/pmoA</I>. Meanwhile, RSB contributed to methane production because of its small particle size in this study. The biochar particle size could be further optimized during large-scale aerobic composting process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> RSB increased the pore methane concentration during aerobic composting. </LI> <LI> The <I>mcrA</I>/<I>pmoA</I> ratio is increased by addition of RSB. </LI> <LI> RSB increased the richness of <I>Methanobrevibacter</I> and <I>Methylobacterium.</I> </LI> <LI> <I>Methanobrevibacter and Methylobacterium</I> showed some correlation with total OM. </LI> </UL> </P>