Weiss Bruno, Souza Anna Carolina Oliveira, Constancio Milena Tavares Lima, Alvarenga Danillo Oliveira, Pylro Victor S, Alves Lucia M Carareto, Varani Alessandro M
Departament of Technology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo 14884-900, Brazil.
Graduate Program in Agricultural and Livestock Microbiology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo 14884-900, Brazil.
Microorganisms. 2021 May 5;9(5):995. doi: 10.3390/microorganisms9050995.
Second-generation biofuel production is in high demand, but lignocellulosic biomass' complexity impairs its use due to the vast diversity of enzymes necessary to execute the complete saccharification. In nature, lignocellulose can be rapidly deconstructed due to the division of biochemical labor effectuated in bacterial communities. Here, we analyzed the lignocellulolytic potential of a bacterial consortium obtained from soil and dry straw leftover from a sugarcane milling plant. This consortium was cultivated for 20 weeks in aerobic conditions using sugarcane bagasse as a sole carbon source. Scanning electron microscopy and chemical analyses registered modification of the sugarcane fiber's appearance and biochemical composition, indicating that this consortium can deconstruct cellulose and hemicellulose but no lignin. A total of 52 metagenome-assembled genomes from eight bacterial classes (Actinobacteria, Alphaproteobacteria, Bacilli, Bacteroidia, Cytophagia, Gammaproteobacteria, Oligoflexia, and Thermoleophilia) were recovered from the consortium, in which ~46% of species showed no relevant modification in their abundance during the 20 weeks of cultivation, suggesting a mostly stable consortium. Their CAZymes repertoire indicated that many of the most abundant species are known to deconstruct lignin (e.g., ) and carry sequences related to hemicellulose and cellulose deconstruction (e.g., , , , and ). Taken together, our results unraveled the bacterial diversity, enzymatic potential, and effectiveness of this lignocellulose-decomposing bacterial consortium.
第二代生物燃料的生产需求旺盛，但木质纤维素生物质的复杂性阻碍了其利用，因为实现完全糖化所需的酶种类繁多。在自然界中，由于细菌群落中生化分工的作用，木质纤维素可以迅速被分解。在这里，我们分析了从土壤和甘蔗制糖厂剩余的干秸秆中获得的一个细菌群落的木质纤维素分解潜力。该菌落在有氧条件下以甘蔗渣为唯一碳源培养20周。扫描电子显微镜和化学分析记录了甘蔗纤维外观和生化组成的变化，表明该菌团可以分解纤维素和半纤维素，但不能分解木质素。从该菌团中总共获得了来自八个细菌类群（放线菌、α-变形菌、芽孢杆菌、拟杆菌、噬纤维菌、γ-变形菌、寡养单胞菌和嗜热放线菌）的52个宏基因组组装基因组，其中约46%的物种在20周的培养过程中丰度没有相关变化，表明该菌团大多是稳定的。它们的碳水化合物活性酶谱表明，许多最丰富的物种已知可以分解木质素（例如），并携带与半纤维素和纤维素分解相关的序列（例如、、和）。综上所述，我们的结果揭示了这个木质纤维素分解细菌菌团的细菌多样性、酶潜力和有效性。
