African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5232

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. 2 College of First Clinical Medicine of Harbin Medical University, 150001 Harbin, China. 3 School of Public Health, University of Michigan, 48109 Ann Arbor, MI, USA.
Email: [email protected]

  •  Accepted: 30 July 2011
  •  Published: 09 November 2011

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: = 16.75 mg/(mg·d), = 7809.36 mg/L and = 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.