假单胞菌中嗜铁素类型、生物合成及应用的研究进展

Research progress in the types, biosynthesis, and application of siderophores in Pseudomonas

摘要:

嗜铁素(siderophore)是一类由细菌在缺铁环境下分泌的小分子量、高亲和力的铁螯合分子。假单胞菌可产生嗜铁素高效螯合环境中难溶性的Fe³⁺，这是细菌适应铁限制环境的关键机制。本文系统综述了假单胞菌嗜铁素的类型、结构特征及其主要合成途径——非核糖体肽合成酶(non-ribosomal peptide synthetase, NRPS)，重点介绍了嗜铁素合成受铁调控蛋白、σ因子、群体感应和双组分系统等多层级调控通路的情况。同时，假单胞菌嗜铁素能促进植物对铁的吸收以及环境修复，也是病原菌感染的毒力因子和致腐菌的重要因子。嗜铁素-铁复合物可被细菌特异性识别并主动摄取，这种“特洛伊木马”机制能促使共价偶联的抗生素潜入菌体，从而显著提升抗菌效果。未来研究需深入解析假单胞菌嗜铁素的分子调控网络及其在微生物互作机制中的作用以推动其在农业、医药和环保领域的应用开发。

Abstract:

Siderophores are low-molecular-weight, high-affinity iron-chelating molecules produced by bacteria in response to iron deficiency. Pseudomonas secrete siderophores to efficiently chelate insoluble Fe³⁺ in the environment, which is a crucial mechanism for their adaptation to iron-limited conditions. This article systematically reviews the types, structural characteristics, biosynthetic pathways (the non-ribosomal peptide synthetase,NRPS), and regulatory mechanisms of siderophores in Pseudomonas. Several regulatory factors at multiple levels were vitally elucidated, including Fur protein, σ factors, quorum sensing, and two-component system. Moreover, siderophores not only promote iron absorption in plants and bioremediation to remove pollutants but also are virulence factors in pathogen infection and factors in microbial spoilage. The siderophore-iron complex can be specifically recognized and actively taken up by bacteria, which is known as the “Trojan horse” mechanism, enabling covalently conjugated antibiotics to enter the cell and thus significantly boosting antibiotic efficacy. Future research should delve into the molecular regulatory networks and microbial interaction mechanisms to promote the application and development of siderophores in agriculture, medicine, and environmental protection.