光催化强化生物电化学系统削减污泥中耐药菌与抗生素抗性基因的机制研究

Antibiotic resistant bacteria (ARB) and their carrying resistance genes (ARGs) are important sources of biological risk for sludge. Bioelectrochemical system (BES) is one of the effective methods to inhibit the proliferation of ARB and ARGs in sludge, whose reduction performance requires further promotion. This project aims to construct BES coupled with photocatalysis, where photocatalytic reaction couples with anode to enhance the reduction of ARB and ARGs in sludge, through a three-step research: 1) controllable construction of coupling system; 2) characterization of the reduction performance of ARB and ARGs; and 3) revelation of enhancing mechanism. Firstly, the controllable construction law of BES coupled with photocatalysis for reduction of ARB and ARGs in sludge will be revealed, through characterizing the growth law of biofilm and catalytic activity of anode. Next, the enhancing effect of the photocatalysis coupling on reduction process will be verified, and the impact mechanism of operating condition on reduction of ARB and ARGs will be interpreted. Furthermore, the synergistic effect of photocatalysis and BES on reduction of ARB and ARGs will be identified, the structure-activity relationship between typical microorganism and their functional genes and the reduction of ARB and ARGs will be interpreted, and the reduction mechanism of ARB and ARGs within sludge in BES enhanced by photocatalysis will be revealed. The study will offer new ideas and methods for effectively inhibiting proliferation of ARB and diffusion of ARGs, and provide theoretical and technical supports for reduction of biological risk for sludge.

耐药菌（ARB）与抗生素抗性基因（ARG）是污泥生物风险的重要来源。生物电化学系统（BES）是有效抑制污泥中ARB与ARG扩散增殖的方法之一，然而其削减作用有待进一步提升。本项目提出将光催化反应与BES阳极耦合，构造可强化削减污泥ARB与ARG的光催化BES，基于“系统可控构建-效能特性解析-强化机制揭示”的研究主线，首先，通过表征生物膜生长规律和阳极催化活性，揭示高效削减污泥ARB与ARG的光催化BES可控构建规律；进而，探明光催化对削减行为的强化作用，解析运行条件对ARB与ARG削减效能的影响机制；最终，明确光催化与BES削减ARB与ARG的协同作用，阐释典型微生物及其功能基因分布同ARB与ARG削减之间的构效关系，揭示光催化强化BES削减污泥ARB与ARG的作用机制。本研究预期成果将为高效抑制污泥中ARB增殖和ARG扩散提供新的思路和方法，为降低污泥的生物风险提供理论依据和技术支撑。

抗生素耐药菌（Antibiotic Resistant Bacteria，ARB）与抗生素抗性基因（Antibiotic Resistance Genes，ARGs）是污泥生物风险的重要来源。生物电化学系统（Bioelectrochemical system，BES）是有效抑制污泥中ARB与ARGs扩散增殖的方法之一，其削减作用有待进一步提升。.本项目开发了光催化生物电化学系统，揭示了TiO2纳米管紫外光催化处理对污泥ARGs的削减效能及阻断转移机制，研究发现，TiO2纳米管紫外光催化产生的活性氧一方面会破坏Kofleria、Nitrospira等潜在宿主细菌的细胞结构，引起胞内ARGs和可移动基因元件释放至胞外，另一方面会对胞外ARGs和移动遗传元件产生氧化作用，阻断ARGs在细菌间的水平转移。本项目研究了CaO2投加对生物电化学系统高效削减ARGs的影响，获得了高达16.3%的甲氧苄氨嘧啶抗性基因削减，解析了引入生物电化学技术与过氧化钙高级氧化技术对抗性基因迁移转化的贡献权重，从可移动基因元件、微生物群落结构、金属抗性基因等关键因子与抗性基因丰度分布关系的角度揭示了抗性基因的高效削减机制。本项目的研究成果一方面为有效抑制污泥中ARB增殖和ARGs水平转移提供新的思路和方法，另一方面为实现污泥的安全、高效处置提供新途径。