离子液体促进环境耐药基因增殖扩散机制研究

Ionic liquids (ILs), considered as “environmental friendly” replacements for industrial organic solvents, have been widely applied in modern industry. Our previous studies demonstrated that imidazole ionic liquids can promote antibiotic resistance gene proliferation in the environment, indicating a potential risk of ionic liquid emissions to the environment. Based on our previous studies, we intend to adopt the combination of field sampling and microcosm experiments, laboratory construction of conjugation transfer and transformation systems with pure culture and mixed environmental bacteria, respectively, as well as selecting imidazole and quaternary ammonium salt ionic liquid as the targets to study the distribution and fate of the ionic liquid in industrial wastewater treatment system and its receiving environments. Then the high-throughput sequencing and functional genomics research strategy are performed to study the impact and mechanism of ionic liquids on the environment; and the RNA expression of functional genes and protein expression are conducted to reveal the molecular mechanisms of antibiotic resistance gene propagation caused by ILs in the environment. This study provides a theoretical basis for assessing the ecological risk of ionic liquid emissions into the environment and alleviating the increasingly serious problem of bacterial resistance.

离子液体被誉为“环境友好型绿色溶剂”，已逐步替代传统有机溶剂应用日益广泛。我们的前期研究发现，咪唑类离子液体能够促进环境耐药基因的增殖，预示了离子液体排放进入环境的潜在风险。在前期研究基础上，本研究拟采取野外采样和室内模拟相结合的方法，实验室构建纯菌和环境混合菌的接合转移和转化研究体系，拟选取咪唑类和季铵盐类离子液体作为目标物，考察离子液体在工业废水处理系统以及受纳环境水体中的分布和归趋。采取现代高通量测序和功能基因组学研究策略研究离子液体对环境菌群结构的影响及机制，以功能基因的RNA表达和蛋白表达揭示离子液体促进环境耐药基因增殖扩散的分子机制。本研究对于揭示离子液体排放进入环境的生态风险，缓解日趋严重的细菌耐药性问题提供理论依据。

离子液体（IL）被誉为“环境友好型绿色溶剂”正逐步替代传统有机溶剂被广泛应用。本研究对多种离子液体建立了系列分析方法，但由于离子液体种类繁杂，性质差异巨大，未来对离子液体全面系统的研究还依赖于分析方法的突破；我们检测了数百份环境样本中的6种IL，检出率9%-27%，单独种类的IL浓度不高，但考虑到IL繁杂的种类，其环境污染总浓度不容忽视；通过环境样本构建的IL暴露实验体系，我们发现多种类IL显著促进耐药基因增殖和传播，不同侧链结构的IL促进作用不同，不同阳离子的IL促进作用也不相同，但不同阴离子的IL的促进作用差异不显著；IL胁迫细菌的运动、趋化和致病相关基因的表达均有一定改变，表现为生理生化性能的改变；IL胁迫细菌的膜孔蛋白和性菌毛蛋白表达增强而促进了细菌接合转移装置的形成，从而促进了耐药基因的水平转移。本研究从多维度（基因和蛋白的分子水平和细菌细胞整体水平）揭示了不同结构和组成的IL（不同侧链长度、不同阳离子、不同阴离子的IL等）对细菌生理和耐药基因增殖扩散的影响，并探讨了潜在机制，为后续IL的健康风险研究奠定了基础。