Acinetobacter sp.SL-1处理含铬废水过程中重金属与抗生素的交叉抗性研究

Cross-resistance of Acinetobacter sp. SL-1 to heavy metal and antibiotics in the treatment of chromium-containing wastewater

选用Acinetobacter sp.SL-1菌株研究其在含铬废水处理过程中重金属与抗生素的交叉抗性。实验结果表明:该菌株对Cr(Ⅵ)的最大耐受质量浓度为300mg/L;在无Cr(Ⅵ)胁迫下,对四环素、庆大霉素、克拉霉素与氧氟沙星呈中介药敏性(I);在含Cr(Ⅵ)条件下,该菌株对以上4种抗生素的药敏性变低,呈耐药性(R)。二元交叉培养中,该菌株对Cr(Ⅵ)与抗生素的耐受性发生了明显变化。通过分析菌株在受Cr(Ⅵ)胁迫后的胞外聚合物的成分和含量以及宏基因组基因功能注释,解释了生物被膜作用与外排泵作用是该菌对Cr(Ⅵ)与抗生素存在交叉抗性的原因,为进一步研究微生物法处理含铬废水过程中产生新的抗生素抗性基因污染造成潜在环境风险提供理论支撑。

In this study,Acinetobacter sp.SL-1strain was selected to study the cross-resistance to heavy metal and antibiotics in the process of chromium-containing wastewater treatment.The results showed that the maximum tolerance concentration of Cr(Ⅵ)was 300 mg/L.In the absence of Cr(Ⅵ)stress,the results showed intermediate drug(I)sensitivity to tetracycline,gentamicin,clarithromycin,and ofloxacin.Under the condition of Cr(Ⅵ)stress,the strain showed lower drug sensitivity to the above four antibiotics and showed drug resistance(R).The tolerance of the strain to Cr(Ⅵ)and antibiotics was significantly changed in binary cross culture.By analyzing the composition and quantity of extracellular polymeric substances and the metagenomic genes functional annotation of the strain under the stress of Cr(Ⅵ),the results explained that the biofilm and efflux pump were the main reasons for the crossresistance of the strain to Cr(Ⅵ)and antibiotics.It provides theoretical support for further study of potential environmental risks caused by new antibiotic resistance gene contamination in the process of microbial treatment of chromium-containing wastewater.