ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 14 (4), pp. 001-007, April, 2020. © International Scholars Journals
Full Length Research Paper
Isolation and characterization of Rhodococcus sp.BX2 capable of degrading bensulfuron-methyl
Minghua Xiong1, Chunyan Li1*, Junbo Pan1, Xiaosong Cheng2, and Chuanwu Xi3
1College of Resource and Environment, Northeast Agricultural University, 150030 Harbin, China.
2College of First Clinical Medicine of Harbin Medical University, 150001 Harbin, China.
3School of Public Health, University of Michigan, 48109 Ann Arbor, MI, USA.
Accepted 30 July, 2019
Abstract
Bensulfuron-methyl (BSM) is a widely applicable sulfonylurea herbicides. However, BSM remains in environment for extended period of time (over 100 days) and causes a series of environmental problems. In this study, BX2, a strain presents high BSM degradation abilities, was isolated from an activated sludge sample using a continuous enrichment method and determined to be a member of the genus Rhodococcus based on its physiobiochemical characteristics and 16S rRNA gene sequence. Strain BX2 degradated 92% BSM from an initial concentration of 20 mg/L within a 7- day incubation at 35℃. The specific degradation rate increased with an increase in the initial BSM concentration and the maximum specific degradation rate obtained was 0.146 mg/(mg•d) at 140 mg/L. BSM degradation by strain BX2 can be presented by Haldane’s inhibition equation and the kinetic parameters were: vm ax = 16.75 mg/(mg•d), ks = 7809.36 mg/L and ki = 2.41 mg/L, respectively. These results indicated that the strain BX2 could be an excellent candidate for bioremediation of BSM-contaminated environments due to its high BSM-degradative ability.
Key words: Bensulfuron-methyl (BMS); Rhodococcus sp.BX2; Isolation; Biodegradation.