CORESTA Congress, Quebec, 2014, Agronomy/Phytopathology Groups, AP 35

Screening, identification and characterisation of an Arthrobacter sp. strain MC-10 capable of degrading quinclorac

CHEN Dexin(1); ZHANG Shun(1,2); HUANG Guolian(3); XU Jialai(4); LI Bin(5); LI Hongguang(3)
(1) Qingzhou Tobacco Research Institute of CNTC, Qingdao, P.R. China; (2) Chinese Academy of Agricultural Sciences, Graduate School, Beijing, P.R. China; (3) Hunan Chenzhou Tobacco Company, Chenzhou, P.R. China; (4) Shandong Tobacco Research Institute, Ji’nan, P.R. China; (5) Sichuan Tobacco Company, Chengdu, P.R. China

The objective of this study was to screen strains able to degrade quinclorac efficiently. The strains were isolated from the perennial administration quinclorac paddy fields. The strain MC-10, which can degrade quinclorac efficiently, was screened by enrichment and selective medium. The strain was identified by morphological, physio-biochemical characteristics and 16S rRNA gene sequence analysis. MC-10 was identified as Arthrobacter sp. Under the optimal growth conditions with inoculum concentration of 5%, at 28 °C, pH 7 for 7 days, MC-10 had high biological activity and can degrade more than 90% of quinclorac. Degradation conditions for MC-10 are best at pH 7 and 30 °C. MC-10 can effectively degrade quinclorac when quinclorac initial concentration is within the range 1-100 ppm. And the strain MC-10 has a good ability to survive in the soil. More than 70% quinclorac in the soil can be degraded efficiently after four days of cultivation. These results indicated that Arthrobacter sp. MC-10 could be a promising microorganism in dealing with quinclorac pollution. Degradation of quinclorac can reduce the influence of pesticide residues in soil to the next crops, which will have a positive impact on reducing environmental and soil pollution and have positive economic and social benefits.