Centre for Marine BioInnovation (CMB), School of Biotechnology and Biomolecular Sciences (BABS), University of New South Wales (UNSW), Sydney, NSW, 2052, Australia.
Environ Microbiol Rep. 2013 Dec;5(6):778-86. doi: 10.1111/1758-2229.12085. Epub 2013 Jul 25.
Bacteria adhere to natural and engineered surfaces and develop into mature biofilms encased in self-produced extracellular polymeric substances (EPSs). EPS consists of polysaccharides, proteins, metabolites and extracellular DNA (eDNA). Extracellular DNA release by bacteria is mediated by both quorum-sensing (QS)-dependent and -independent mechanisms. Quorum-sensing-independent mechanisms are responsible for basal levels of eDNA release, whereas QS-dependent mechanisms control the production of prophages, phenazines and proteins involved in cell lysis and subsequent release of elevated amounts of eDNA. Extracellular DNA binds with other biopolymers such as polysaccharides, proteins or metabolites like phenazines, thereby providing structural integrity to EPS. Extracellular DNA promotes attractive acid-base interactions between bacterial cells and between bacteria and surfaces. It therefore plays an essential structural role in stabilising biofilms and protecting bacterial cells from physical and chemical challenges. Accordingly, with current knowledge, it becomes clear that targeting and destroying eDNA in bacterial EPS is a promising strategy for treatment of bacterial-associated infections in a medical context and biofilm control on surfaces to prevent biocorrison in an engineering context. In contrast, the addition of DNA can be applied to engineering of biofilms for beneficial purposes such as remediation of environmental pollutants and electricity or fuel production in bioelectrochemical systems or bioreactors.
细菌会黏附在天然和人工表面，并形成成熟的生物膜，被自身产生的胞外聚合物质 (EPS) 包裹。EPS 由多糖、蛋白质、代谢物和细胞外 DNA（eDNA）组成。细菌通过群体感应（QS）依赖和独立的机制来释放细胞外 DNA。QS 独立机制负责基础水平的 eDNA 释放，而 QS 依赖机制控制着噬菌体、吩嗪和参与细胞裂解及随后大量 eDNA 释放的蛋白质的产生。细胞外 DNA 与其他生物聚合物（如多糖、蛋白质或代谢物如吩嗪）结合，从而为 EPS 提供结构完整性。细胞外 DNA 促进了细菌细胞之间以及细菌与表面之间的有吸引力的酸碱相互作用。因此，它在稳定生物膜和保护细菌细胞免受物理和化学挑战方面发挥着重要的结构作用。因此，根据目前的知识，很明显，靶向和破坏细菌 EPS 中的 eDNA 是一种有前途的策略，可以用于治疗医学背景下与细菌相关的感染，并控制表面上的生物膜以防止在工程背景下的生物腐蚀。相比之下，DNA 的添加可用于生物膜的工程设计，以实现有益的目的，如修复环境污染物和在生物电化学系统或生物反应器中产生电力或燃料。
