高丝氨酸内酯衍生物的合成表征及在砷胁迫下对氧化亚铁硫杆菌BY-3生物膜形成的影响（英文）

Characterization of acylated homoserine lactone derivatives and their influence on biofilms of Acidithiobacillus ferrooxidans BY-3 under arsenic stress

群体感应作为微生物间的信号传递系统,通常借助微生物产生的诱导分子高丝氨酸内酯(AHL)或寡肽来响应种群密度。本研究通过化学合成法合成了14种AHL衍生物,采用结晶紫染色法筛选证实两种衍生物在砷环境下对氧化亚铁硫杆菌的生物膜抑制效应更加明显,并通过红外光谱(IR)及核磁共振(1H NMR、13C NMR)对其进行了结构表征,借助透射电镜分析了菌种形态的变化,同时探讨了两种衍生物在0.1μg/mL及1μg/mL浓度下对高砷(1600 mg/L)胁迫下的氧化亚铁硫杆菌生物膜形成的影响。研究结果表明在高砷环境下培养至对数期的氧化亚铁硫杆菌菌体出现结构改变,且加入高浓度高丝氨酸内酯衍生物后,菌体体积变小,胞外聚合物降低,同时0.1μg/mL及1μg/mL浓度的两种AHL衍生物皆能有效抑制氧化亚铁硫杆菌生物膜的产生。

Quorum sensing is one kind of cell-to-cell signalling system among microorganisms that works in response to their population density via autoinducers exemplified by AHL and oligopeptides. In this study, fourteen AHL derivatives were synthesised by a chemical synthesis method, and two types of AHL derivatives were measured and screened by crystal violet staining assay, which have more obvious inhibitory effects on A. ferrooxidans biofilms under arsenic environment. Their structures were verified through IR and NMR identification. The morphological changes of A. ferrooxidans under the influence of the AHL derivatives were compared. In addition, the effects of AHL derivatives(0.1 μg/mL and 1 μg/mL) on membrane formation of A. ferrooxidans under high concentration of arsenic resistance(1,600 mg/L) were explored. Solid experimental data firstly showed that a portion of logarithmic microorganisms were ruptured under the effect of high arsenic concentration. Secondly, the volume of the cell shrank and the number of extracellular polymeric substances decreased after the addition of the AHL derivatives at high concentrations. Therefore, we found here that two derivatives used at concentrations of 0.1 μg/mL and 1 μg/m L accompanied with high concentration of arsenic can both effectively restrict biofilms formation by A. ferrooxidans.