Lignocellulose-Degrading Microbial Communities in Landfill Sites Represent a Repository of Unexplored Biomass-Degrading Diversity.
Lignocellulose-Degrading Microbial Communities in Landfill Sites Represent a Repository of Unexplored Biomass-Degrading Diversity.
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DOI：
10.1128/msphere.00300-17
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发表时间：
2017-07
期刊：
影响因子：
4.8
通讯作者：
McDonald JE
中科院分区：
文献类型：
--
作者：
Ransom-Jones E;McCarthy AJ;Haldenby S;Doonan J;McDonald JE
微生物转化木质纤维素生物质生产生物燃料代表了化石燃料的可再生替代品。然而，发现新的具有高活性的微生物酶对于改善生物质转化过程至关重要。虽然鉴定优质木质纤维素降解酶的尝试主要集中在动物肠道上，但垃圾填埋场中的生物质降解群落代表了生物质转化水解酶的未开发资源。在这里，我们确定厚壁菌门、螺旋体和纤维杆菌是垃圾填埋场纤维素分解群落的关键门，检测到8,371种碳水化合物活性酶（CAZymes），这些酶至少代表了纤维素分解的三种已知策略。这些数据突出了垃圾填埋场中大量水解酶的多样性，作为生物质转化新酶的来源。微生物转化木质纤维素生物质生产生物燃料代表了化石燃料的可再生替代品。然而，发现新的具有高活性的微生物酶对于改善生物质转化过程至关重要。虽然鉴定优质木质纤维素降解酶的尝试主要集中在动物肠道上，但垃圾填埋场中的生物质降解群落代表了生物质转化水解酶的未开发资源。为了解决胃肠道以外的生物质降解微生物多样性信息匮乏的问题，在垃圾渗滤液中培养纤维素（棉花）“诱饵”，以丰富垃圾填埋场纤维素降解微生物群落，进行分类和功能表征。宏基因组和16S rRNA基因扩增子测序显示厚壁菌门、拟杆菌门、螺旋体和纤维杆菌在垃圾填埋场纤维素分解群落中占主导地位。功能宏基因组分析显示，共有8371个碳水化合物活性酶（CAZymes），属于244个CAZyme家族。除了观察厚壁菌门成员的厌氧细菌“纤维素体”系统的生物质降解酶外，我们还报道了在垃圾填埋场中首次检测到纤维杆菌纤维素酶系统和拟杆菌门多糖利用位点（PUL）。这些数据为垃圾填埋场微生物群中存在多种生物质降解机制提供了证据，并突出了垃圾填埋场微生物作为具有潜在生物技术意义的生物质降解酶的丰富来源的非凡功能多样性。微生物转化木质纤维素生物质生产生物燃料代表了化石燃料的可再生替代品。然而，发现新的具有高活性的微生物酶对于改善生物质转化过程至关重要。虽然鉴定优质木质纤维素降解酶的尝试主要集中在动物肠道上，但垃圾填埋场中的生物质降解群落代表了生物质转化水解酶的未开发资源。在这里，我们确定厚壁菌门、螺旋体和纤维杆菌是垃圾填埋场纤维素分解群落的关键门，检测到8,371种碳水化合物活性酶（CAZymes），这些酶至少代表了纤维素分解的三种已知策略。这些数据突出了垃圾填埋场中大量水解酶的多样性，作为生物质转化新酶的来源。
The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, we identified Firmicutes, Spirochaetes, and Fibrobacteres as key phyla in the landfill cellulolytic community, detecting 8,371 carbohydrate active enzymes (CAZymes) that represent at least three of the recognized strategies for cellulose decomposition. These data highlight substantial hydrolytic enzyme diversity in landfill sites as a source of new enzymes for biomass conversion. The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, to address the paucity of information on biomass-degrading microbial diversity beyond the gastrointestinal tract, cellulose (cotton) “baits” were incubated in landfill leachate microcosms to enrich the landfill cellulolytic microbial community for taxonomic and functional characterization. Metagenome and 16S rRNA gene amplicon sequencing demonstrated the dominance of Firmicutes, Bacteroidetes, Spirochaetes, and Fibrobacteres in the landfill cellulolytic community. Functional metagenome analysis revealed 8,371 carbohydrate active enzymes (CAZymes) belonging to 244 CAZyme families. In addition to observing biomass-degrading enzymes of anaerobic bacterial “cellulosome” systems of members of the Firmicutes, we report the first detection of the Fibrobacter cellulase system and the Bacteroidetes polysaccharide utilization locus (PUL) in landfill sites. These data provide evidence for the presence of multiple mechanisms of biomass degradation in the landfill microbiome and highlight the extraordinary functional diversity of landfill microorganisms as a rich source of biomass-degrading enzymes of potential biotechnological significance. IMPORTANCE The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, we identified Firmicutes, Spirochaetes, and Fibrobacteres as key phyla in the landfill cellulolytic community, detecting 8,371 carbohydrate active enzymes (CAZymes) that represent at least three of the recognized strategies for cellulose decomposition. These data highlight substantial hydrolytic enzyme diversity in landfill sites as a source of new enzymes for biomass conversion.