Li Wei, Wang Jing Jing, Qian Hui, Tan Ling, Zhang Zhaohuan, Liu Haiquan, Pan Yingjie, Zhao Yong
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.
Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of Agriculture, Shanghai, China.
Front Microbiol. 2020 May 19;11:813. doi: 10.3389/fmicb.2020.00813. eCollection 2020.
The extracellular polymeric substances (EPS) construct the three-dimensional (3-D) structure of biofilms, but their respective roles are still not clear. Therefore, this study aimed to illuminate the role of key chemical components [extracellular DNA (eDNA), extracellular proteins, and carbohydrates] of EPS in biofilm formation of . The correlations between each key chemical component and biofilm formation were first determined, showing that the biofilm formation of was strongly positively correlated with both eDNA and protein content ( < 0.01), but not with carbohydrates. Subsequently, individual DNase I or protease K treatment markedly reduced the initial adhesion and structural stability of the formed biofilms by hydrolyzing the eDNA or extracellular proteins, but did not induce significant dispersion of mature biofilms. However, the combination of DNase I and protease K treatment induced the obvious dispersion of the mature biofilms through the concurrent destruction of eDNA and extracellular proteins. The analysis at a structural level showed that the collapse of biofilms was mainly attributed to the great damage of the loop configuration of eDNA and the secondary structure of proteins caused by the enzyme treatment. Therefore, this study provides a deep understanding of the role of key chemical components of EPS in biofilm development of , which may give a new strategy to develop environmentally friendly methods to eradicate the biofilms in food industry.
胞外聚合物（EPS）构建了生物膜的三维（3-D）结构，但其各自的作用仍不明确。因此，本研究旨在阐明EPS的关键化学成分[细胞外DNA（eDNA）、细胞外蛋白质和碳水化合物]在[生物膜形成中的作用]。首先确定了每种关键化学成分与生物膜形成之间的相关性，结果表明[生物膜的形成与eDNA和蛋白质含量均呈强正相关（<0.01），但与碳水化合物无关。随后，单独用脱氧核糖核酸酶I或蛋白酶K处理通过水解eDNA或细胞外蛋白质显著降低了形成的生物膜的初始附着力和结构稳定性，但未诱导成熟生物膜的显著分散。然而，脱氧核糖核酸酶I和蛋白酶K联合处理通过同时破坏eDNA和细胞外蛋白质诱导了成熟生物膜的明显分散。结构水平分析表明，生物膜的坍塌主要归因于酶处理对eDNA环构型和蛋白质二级结构的巨大破坏。因此，本研究深入了解了EPS关键化学成分在[生物膜发育中的作用]，这可能为开发环保方法以根除食品工业中的生物膜提供新策略。
