The Construction Of Optical Microbial Biosensor And Its Application In Monitoring Genotoxicity

Part of the chemicals in the environment generate genotoxicity to creatures, this problem has become one of the environmental issues,and causes more and more attention. Traditional physical and chemical monitoring ways, whether in terms of cost or in efficiency,can’t meet the needs of the monitoring. More importantly, the physical and chemical ways can accurately quantify the analysis of certain chemicals, but they can not reflect its effect to organism.In view of the insufficiency to traditional acute toxicity examination method, at present, the domestic and foreign researchers have established many kinds of biology experimental technique to enhance the monitoring method.due to their specificity, high sensitivity, economical and simple,the quickly analysis speed, and can the online continuously monitoring compound toxicants in a complex system,make them have attractive prospect in the environmental monitoring application. Especially, owing to its advantages on short detection time and high sensitivity,optical microbial biosensor has already been widely used in detection of toxicity.Therefore, we taked the recombinant TA1535-14as the sensing element, a Y-type quartz fiber as the conductive fiber, the fluorescence spectrometer detected the optical signals,to build up a microbial biosensor. After the microbial biosensor was set-up,we done preliminary test with the biosensor with the four genotoxic positive material:MMC,phenoI,H2O2and4-NQO.(1)Take the recombinant Salmonella TA1535-Pcda:GFP as the material, multitube glycerine preserved strains of recombinant Salmonella TA1535-Pcda:GFP were resurrect in LB medium and screened in LB+Amp medium, the survived strains that can growed in LB+Amp medium were separated and purified, furthermore, verified their function. According to experimental result,we taked the recombinant TA1535-14as the sensing element to build up a microbial biosensor.The embedded conditions were fumbled about, its embedding conditions were as follows:5%sodium alginate (SA) as the embedding medium,5%CaCl2solution as the crosslinking agent, the volume ratio of SA and bacteria is1:5. The characteristics of the bacteria were also studied. The optimal incubation temperature of strain is30℃, and the initial inoculum concentration (OD600) is0.8.(2) After compared the conduction performance of the three types fiber, the Y-type quartz optical fiber was selected as the conductive fiber, the fluorescence spectrometer detected the optical signals,to set up the microbial biosensor,and to do preliminary test with the biosensor with the four genotoxic positive material:MMC, phenol, H2O2and4-NQO. Their detections and linear range are as below:MMC:0.01μg/mL,the linear range is1×10-2～6×10-2μg/mL;Phenol:2×102μg/mL,the linear range is2×102-2.6×102μg/mL;H2O2:10μmol/L, the linear range is10-18μmol/L; 4-NQO:0.10μg/mL, the linear range is0.10-0.80μg/mL.Topically, the microbial biosensor we built showed well detection,high sensitivity, economic, efficient, and easy to operate to the detection of genotoxicity. This experiment provided a basis and reference for the microbial biosensor in the application to rapidly detecte the genotoxicity and environmental monitoring, and has important practical significance to the rapid detection of environmental pollutants.