细菌对环境污染物的趋化性及其在生物修复中的作用

细菌对有机化合物的降解能力是一种利用碳源和能源的优势,这种能力可以用来设计安全、有效和无二次污染的污染物的生物修复系统。趋化性是细菌适应外界化学环境变化而作出的行为反应,是一种寻找碳源和能源的优势。细菌的趋化性能够增强细菌在自然环境中的降解污染物的效果,细菌的趋化性与降解性之间的关系研究已经成为热点。介绍了细菌的趋化性的基本概念和趋化信号转导的机制,重点讨论了细菌对环境污染化合物的趋化性,从基因水平揭示了趋化性与降解性之间的紧密联系,认为趋化性可以有效地促进降解性细菌对污染物的生物修复作用。

Bacterial chemotaxis to environmental pollutants and it's significance in bioremediation

Release of pollutants has resulted in environmental contamination. Many methods have been applied to remove xenobiotic compounds, and bioremediation was considered as a safer, more efficient and less expensive alternative to treat these pollutants. Although many environmental pollutants are found to be degraded by microorganisms, in some cases, the catabolic potential alone was inadequate, combining with other properties such as chemotaxis to enhance bioremediation has been considered. Bacterial chemotaxis, movement of bacteria under the influence of a chemical gradient helped bacteria to navigate to the most favorable niches for growth and survival, and it might have evolved as a selective advantage to bacteria for searching the chemicals that could act as a source of carbon and energy to the cells. Chemotaxis could play an important role in the biodegradation process. The relationships between chemotaxis and degradation have been studied with increasing efforts. In this review, the basic concept and assay methods of bacterial chemotaxis and it's signal transduction mechanism are introduced. Bacterial chemotaxis to environmental pollutants is discussed in detail, and evidences that motile bacteria are chemotactically attracted to environmental pollutants, which they could degrade, are listed. The relationships between chemotaxis and degradation characteristics are discussed on genetic levels, and the evidences demonstrating that chemotaxis and biodegradation genes of 4-hydroxybenzoate, toluene, naphthalene and 2,4-D were coordinately regulated suggesting that these processes are intimately linked in nature. Chemotaxis could enhance degrading ability in bioremediation, and knowledge of bacterial chemotaxis toward xenobiotics could be applied in designing efficient systems for bioremediation of contaminated sites.