标题：The substrate-dependent regulatory effects of the AfeI/R system in Acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles
作者：Gao X.-Y.; Fu C.-A.; Hao L.; Gu X.-F.; Wang R.; Lin J.-Q.; Liu X.-M.; Pang X.;等 更多 作者机构：[Gao, X.-Y] State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, China;[ Fu, C.-A] State Key Labora 更多
通讯作者地址：[Lin, J.-Q] State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, State Key Laboratory of Microbial Technology, Shand 更多
摘要：A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and iron-oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats. © 2020 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.