Graduate School of Medicine, Engineering and Agricultural Sciences, University of Yamanashi, Kofu 400-8510, Yamanashi, Japan.
FEMS Microbiol Lett. 2021 Mar 3;368(4). doi: 10.1093/femsle/fnab015.
Weed, an abundant biomass, is considered unsuitable as a raw material for methane production. There are few reports on the anaerobic digestion of weeds without the addition of other organic wastes. To solve this problem, a methane-producing microbial community with weed as a sole feedstock was established. This study mainly focused on the degree of contribution between water-soluble and -insoluble fractions of the weed to methane production; thus, methane production from both fractions was tested separately. Methane production after 80-day batch cultures with whole weed, water-soluble and water-insoluble fractions was 184.5, 96.8 and 26.5 NmL g-1 dry matter (DM), respectively. The results of 16S rRNA gene amplicon sequence analysis revealed that Proteiniphilum saccharofermentans and several Methanobacterium species commonly dominated all cultures, whereas the population dynamics of minor species differed in every culture. Moreover, the remixed culture of microbial communities adapted to water-soluble and -insoluble fractions recovered methane production (252.4 NmL g-1 DM). Based on these results, it can be strongly inferred that colocalizing the minor species in water-soluble and -insoluble fractions is important for effective methane production.
杂草是一种丰富的生物质，但因其不适合作为甲烷生产的原料而被忽视。很少有关于在不添加其他有机废物的情况下对杂草进行厌氧消化的报道。为了解决这个问题，我们建立了一个以杂草为唯一原料的产甲烷微生物群落。本研究主要关注杂草的水溶性和不溶性部分对甲烷生产的贡献程度；因此，分别测试了这两部分的甲烷生产情况。经过 80 天的分批培养，整株杂草、水溶性和水不溶性部分的甲烷产量分别为 184.5、96.8 和 26.5 NmL g-1 干物质（DM）。16S rRNA 基因扩增子序列分析的结果表明，发酵蛋白菌（Proteiniphilum saccharofermentans）和几种甲烷杆菌（Methanobacterium）通常在所有培养物中占主导地位，而每个培养物中的次要物种的种群动态都有所不同。此外，适应水溶性和不溶性部分的微生物群落的再混合培养恢复了甲烷生产（252.4 NmL g-1 DM）。基于这些结果，可以强烈推断出，在水溶性和不溶性部分中共同存在次要物种对于有效生产甲烷非常重要。
