摘要
The wastewater discharge from the process of chrome plating,which contains 6:2 chlorinated polyfluorinated ether sulfonate(F-53B)and chromium(Cr),may be toxic to biofilm.In this study we found that the biofilm formed by Pseudomonas aeruginosa PAO1 was inhibited by exposure to a combination of F-53B and Cr(VI).The combined pollution damaged the cell membranes and the structure of the biofilm,and inhibited the production of the Pseudomonas quinolone-based signal,which affected biofilm formation.Moreover,the secretion of extracellular polymeric substances decreased as a result of this combined exposure.Exposure to F-53B and Cr(VI)individually or in combination could induce the excessive accumulation of intracellular reactive oxygen species(ROS),and the ROS positive rate of the bacteria increased under the treatment with 0.2 mmol/L of Cr(VI)and 250 nmol/L of F-53B,respectively.In addition,the activities of superoxide dismutase(SOD)and catalase(CAT)were enhanced for scavenging ROS in the bacteria that were exposed to Cr(VI)and F-53B.As an antioxidant,rutin was used to repair the toxicity of Cr(VI)and F-53B towards the biofilm formed by the bacteria.When rutin was added to the bacteria medium,with either Cr(VI)or F-53B as pollutant,or with the combined pollutants,the extracellular protein content of the bacteria recovered to 0.84,0.94,and 0.85 times that of the control,respectively.Meanwhile,the accumulation of ROS and the activities of SOD and CAT decreased,which indicated that the addition of rutin can alleviate the oxidative stress and promote the antioxidant stress system.
基金
supported by the Natural Science Foundation of Jiangsu Province(No.BK20201388)
the Industry Prospect and Common Key Technologies in Jiangsu Province(No.BE2018015)
the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
