细菌脂肪酶基因表达调控的研究进展

Progress in expression regulation of bacterial lipase genes-A review

微生物脂肪酶是商品化脂肪酶的主要来源,广泛应用于食品、饮料、油脂、洗涤剂、饲料、纺织、皮革、新型材料、精细化工、医药、化妆品、造纸、污染治理、生物能源等工业领域。与真菌脂肪酶相比,细菌脂肪酶催化反应的类型更多、活性更高、稳定性更好,其中又以假单胞菌属(Pseudomonas)脂肪酶的性能最为优越。截至目前,常规育种、培养基和发酵条件优化等策略均不能从根本上解决细菌脂肪酶产量低的问题,而阐明其基因表达调控的分子机制、筛选主效调控因子、构建同源表达基因工程菌是解决问题的有效办法。本文从直接调控因子、群体感应系统、Gac/Rsm信号转导系统、调控Gac/Rsm信号转导系统的调控因子、其他调控因子等方面,对细菌脂肪酶基因表达调控的研究进展进行了评述;结合作者的相关研究结果,对该领域的研究前景进行了展望,以期为基因工程菌的构建提供有益参考。

Microbial lipases are major sources of commercial ones, which have been extensively used in a wide variety of industrial fields, such as foods, beverages, lipids, detergents, feeds, textiles, leathers, advanced materials, fine chemicals, medicines, cosmetics, papermaking, pollution treatment, and bioenergy. Compared with fungal lipases, bacterial lipases have more types of reactions and exhibit higher activity and better stability in aqueous or organic phases. Amongst bacterial lipases, the most excellent ones are those originating from the genus Pseudomonas. So far, the conventional strategies, such as traditional breeding, optimization of medium and fermentation conditions, cannot fundamentally solve the problem of low production of bacterial lipases. Construction of genetically engineered strains to efficiently overexpress their own lipases is an effec.tive solution. But it must base on clarifying molecular regulation mechanism of lipase gene expression and further finding out key regulators. In this article, we reviewed the progress in expression regulation of bacterial lipase genes from the aspects of direct regulators, quorum sensing system, Gac/Rsm signal transduction system, regulators controlling the Gac/Rsm system, and other regulators. To provide a useful reference for the construction of genetically engineered strains, we also discussed a research prospect in this field based on our ongoing research.