群体感应对生物强化过程影响

The Effects of Quorum Sensing on the Bioaugmentation

群体感应是指细菌之间通过信号分子进行交流的现象。信号分子的释放量依赖于菌体的生长密度,常在对数生长期或稳定初期达到最大;此外,相较于正常培养条件,低温、酸性pH、缺氧、高渗透压、碳源及微量元素不足等胁迫环境有利于信号分子的释放并使其稳定存在,从而使菌群通过群体感应实现抵抗胁迫环境的目的。在生物强化过程中,信号分子介导的毒素释放、抗生素产生、胞外聚合物分泌、生物膜形成、质粒转移等群体感应效应可提高菌体定植效率,促进种群动态发育。对生物强化系统内信号分子释放和存在的影响因素以及菌种类型-信号分子种类-群体感应效应方式间的关系进行研究,将有利于从群体感应的角度提高生物强化系统运行的可预测性和可控制性。

Quorum sensing is a bacterial communication with one another using chemical signal molecules. There exists a dependent relationship between the releasing of auto-inducers and the density of bacteria, with a maximum of auto-inducer releasing in the log or stable phase. The stress environments including low temperature, acidic pH, deficient oxygen, high osmotic pressure, shortage of carbon sources and trace elements, while no inhibit on the growth of bacteria, can promote the releasing of auto-inducers and benefit to its existing, which would be favor to resist the environmental stress by bacterial communities. During the process of bioaugmentation, the roles induced by quorum sensing, such as toxin releasing, antibiotic producing, extra-cellular polymeric substances secreting, biofilm forming and plasmid transferring, could improve the efficiency of the bacterial colonization and promote the development of the community structure. Thus, the researches both of the effects of the environmental factors on the releasing and stabilization of auto-inducers and the relationships among the species of bacteria and the categories of auto-inducers and the roles of quorum sensing, would provide solutions to the predictability and controllability of the bioaugmentation.