Construction Of Multi-function Bacteria For Anti-lead And Phenol Degradation

In this paper, did plasmid elimination experiments on efficient phenol-degrading bacteria and anti- lead bacteria, extracted the relevant plasmid and transformed it into E. coli DH5α, preliminarily locat the relevant functional genes.Through transfering plasmid to construct multi-functions environment bacteria which can be anti-Pb and degradate phenol. Test the transformants effection of phenol degradation in the lead environment, while extraction the plasmid of transformants and have a lectrophoresis molecular validation.Studied the effects of different environmental factors on the transformant's growth, the stability of the transformation under different environmental conditions, the transformant's degradation curve under different circumstances.The results obtained are as follows:1, by plasmid elimination experiments, phenol-degrading strain's capability of phenol-degrading significantly reduces, strain of resistance lead remains the original anti-lead characters. Extracted plasmid from the phenol-degrading strains then transformed it into E. coli DH5α, after transforment, E. coli DH5αobtained the phenol-degrading performance.2, extracted the plasmid from phenol-degrading bacteria then transformed into competent cells of anti-lead bacteria, screened out the effective transformant, test transformants'capacity of phenol-degrading when containing high concentrations of lead, the transformants'phenol degradation rate reached 97.4% on 500mg / L of phenol in the first 89h when the concentrations of lead is 100mg / L. That confirmed that plasmid transformtion method can be successfully constructed multi-functional bacteria with both anti- lead and effectively degraded phenol.3, through inoculating a certain amount of the transformants'enriched liquid into the inorganic salt medium with phenol as the sole carbon source, test the concentration of phenol after certain period of time, observed the rate of phenol degradation under different conditions, then measured the transformants'degradation of sub-activity. In the lead concentration of 50 300mg / L, transformants can quickly and effectively degrade the phenol of the substrate.In different initial phenol concentration, the time required for complete degradated phenol by the transformant is quite different, with the phenol concentration was increased, which takes longer. Diffrence of degradation time required for is mainly for the the different lag. The transformation in the 20 25℃, with the temperature, complete degradation time less required for, 25 30℃with the temperature degradation time the longer, when the temperature rose to 35℃, the transformant can not effectively degrade the phenol in culture medium. in the pH of 5 7, the difference in time required for complete degradation of phenol by transformat is not obversely, but when the pH is increased, the phenol degradation was inhibited. with phenol as the sole carbon source to the inorganic salt medium containing glucose, we found that low concentrations of glucose can promote the transformation of the child for phenol degradation, high concentration inhibited.4,By testing lead resistance of phenol-degrading transformants'OD₆₀₀ absorbance values to observed the growth of the transformants in different environments. The transformants in the pH value of 5 9, the temperature within the range of 25 40℃grow well; the transformants'phenol tolerance is strong, was able to maintain a high growth capacity to 500mg / L of phenol; when the speed reached up to 100r/min the transformants grow vigorously.5,Cultureed the transformants under different enrichment environmental conditions ,then diluted the transformants to a phenolic coating selection board and non-phenolic non-selective plate culture, calculate the number of strain on selection boards and non-selectivity, measure the the transformants'stability of genetic expression plasmid in different environmental conditions by the ratio of the number of board colony, to temperature had great influence on its stability, reached 40℃temperatures the plasmid translated into is easier loss. Under phenol stress, as the phenol concentration from 50 500mg / L, transformant's stability increased gradually. On appropriate speeds the stability of transformants is higher, too low or too high a speed would reduce the stability of plasmid in transformants. pH in the range of 5 to 9 pairs of plasmid of stability a relatively small, little impact.