Isolation Of The Quinclorac-degradate Microbes And Studies On The Degradation Of Quinclorac

Strain B51 capable of degrading quinclorac was isolated from the paddy earth by high dosage of herbicide quinclorac. It could use quinclorac as the only carbon and energy to live. In two weeks, stain B51 could able to use 65% of the herbicide in quiclorac MM medium.From the configuration character of the B51 and the 16s rDNA penlogenetic analysis, the strain B51 was considered to be Brodetella.N+man-made was injected to the strain B51, we got one new bacterium B51-3. In two weeks, B51-3 can able to utilize 82% of the herbicide in quinclorac MM. After the experiment of the conditions that B51-3 use quinclorac in Lab, it could make use of 62% quincolrac in 4 days.However, from the conditions of the experiment, we found that B51-3 can utilize quinclorac between 20℃and 42℃, and 30℃-37℃was the best temperature range. If the temperature overrun 30℃-37℃, the efficiency of the strain B51-3 to used quinclorac was lower more than 10%-15%. When the initial pH of the herbicide-quinclorac MM medium were 5.0,6.0,7.0,8.0 and 9.0, B51-3 was able to use quinclorac, especially in 8.0 the use rate of quinclorac was best. The addition of trace element to the quinclorac MM cannot improve the quinclorac degradation rate, in some extent it could restrain the quinclorac degradation. Additionally, yeast extract or glucose acceded to quinclorac MM might not increase the speed of the strain B51-3 to utilized quinclorac, at the same time the growth of bacterium itself was still in low and steady level.