Deng Yijie, Wang Shiao Y
School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Microorganisms. 2022 Jul 26;10(8):1505. doi: 10.3390/microorganisms10081505.
Biofilm commonly forms on the surfaces of cellulosic biomass but its roles in cellulose degradation remain largely unexplored. We used to study possible mechanisms and the contributions of two major biofilm components, extracellular polysaccharides (EPS) and TasA protein, to submerged biofilm formation on cellulose and its degradation. We found that biofilm produced by is able to absorb exogenous cellulase added to the culture medium and also retain self-produced cellulase within the biofilm matrix. The bacteria that produced more biofilm degraded more cellulose compared to strains that produced less biofilm. Knockout strains that lacked both EPS and TasA formed a smaller amount of submerged biofilm on cellulose than the wild-type strain and also degraded less cellulose. Imaging of biofilm on cellulose suggests that bacteria, cellulose, and cellulases form cellulolytic biofilm complexes that facilitate synergistic cellulose degradation. This study brings additional insight into the important functions of biofilm in cellulose degradation and could potentiate the development of biofilm-based technology to enhance biomass degradation for biofuel production.
生物膜通常在纤维素生物质表面形成，但其在纤维素降解中的作用在很大程度上仍未得到探索。我们利用[具体内容缺失]来研究两种主要生物膜成分，即细胞外多糖（EPS）和塔斯A蛋白（TasA），对纤维素上淹没生物膜形成及其降解的可能机制和贡献。我们发现，[具体细菌缺失]产生的生物膜能够吸收添加到培养基中的外源纤维素酶，并且还能将自身产生的纤维素酶保留在生物膜基质内。与产生较少生物膜的菌株相比，产生较多生物膜的细菌降解的纤维素更多。同时缺乏EPS和塔斯A的基因敲除菌株在纤维素上形成的淹没生物膜比野生型菌株少，并且降解的纤维素也更少。纤维素上生物膜的成像表明，细菌、纤维素和纤维素酶形成了促进纤维素协同降解的纤维素分解生物膜复合物。这项研究为生物膜在纤维素降解中的重要功能带来了更多见解，并可能促进基于生物膜的技术发展，以提高生物质降解用于生物燃料生产。
