摘  要：生物体能够合成脂肪酸，它们以不同链长、化学构型和功能存在于体内，参与生物体合成代谢、能量代谢、信号传导等重要的生理活动。生物体能通过不同氧化途径分解和利用脂肪酸，其中β-氧化是真核生物和原核生物中脂肪酸降解的主要途径。脂肪酸β-氧化机理在大肠杆菌中研究得最为广泛和深入。本文首先以大肠杆菌为重点对象，介绍了细菌脂肪酸β-氧化机制的最新研究进展。在此基础上，以植物病原黄单胞菌为代表，介绍了DSF-家族群体感应信号分子（一类中链不饱和脂肪酸）的降解途径和调控机理。基于目前的研究结果，进一步预测了超长链脂肪酸、3-位甲基脂肪酸、2-/3-位双键不饱和脂肪酸和多双键不饱和脂肪酸β-氧化途径中可能需要的特殊酶，并展望了本领域有待深入研究的关键科学问题。本综述为进一步深化脂肪酸β-氧化与细菌致病性相关机理研究提供了坚实的基础。
关键词：细菌；脂肪酸；β-氧化；DSF群体感应信号；细菌致病性
中图分类号：Q935                    文献标志码：A              DOI：10.3969/j.issn.1007-7146.2021.06.003

Abstract: All the living organisms can synthesize various fatty acids, which exist in different carbon chain length, configurations and biological functions. These fatty acids are involved in many important physiological activities including anabolism, energy metabolism, and signal transduction. The living organisms are also capable of degrading and utilizing fatty acids via different oxidative pathways and β-oxidation is one of the most important oxidative pathways in both prokaryotic and eukaryotic cells. Research in the model organism Escherichia coli has provided the most complete view of fatty acids β-oxidation. In this review, the progress of fatty acids β-oxidation in E. coli and other bacterial species were summarized. By taking the phytopathogen Xanthomonas as an example, this review then introduced the oxidation pathway and regulation mechanism of the diffusible signaling factor (DSF)-family quorum sensing signal (mid-chain unsaturated fatty acids). Based on current results, the specific enzymes required for β-oxidation of very-long-chain fatty acids, 3-methyl-fatty acids, Δ2/Δ3-unsaturated fatty acids, and polyunsaturated fatty acids were proposed. Finally, the key scientific questions to be answered in this field were prospected. This review provides a solid foundation for further study of fatty acid β-oxidation pathway and the underlying mechanisms of bacterial pathogenicity.
Key words: bacteria; fatty acid; β-oxidation; DSF-family quorum sensing signal; bacterial pathogenicity
（Acta Laser Biology Sinica, 2021, 30(6): 494-504）