Biodegradation of hexazinone by two isolated bacterial strains (WFX-1 and WFX-2).
Two hexazinone-degrading bacterial strains were isolated from soil by enrichment culture technique, and identified as Pseudomonas sp. and Enterobacter cloacap, respectively. The two purified isolates, designated as WFX-1 and WFX-2, could rapidly degrade hexazinone with half-lives of 3.08 and 2.95 days in mineral salts medium (hereafter referred to as MSM). In contrast, their mixed bacterial culture (herein abbreviated as MBC) was found to degrade hexazinone, at an initial concentration of 50 mg l(-1), by enhancing 2.3-fold over that when the isolates were used alone. The degradation of hexazinone by MBC in MSM clearly decreased concomitant with the increase of initial concentration, and the level of hexazinone that was toxic enough to totally inhibit degradation was in the range of 150-200 mg l(-1). The appropriately combined conditions for hexazinone degradation by MBC in MSM were studied, and found to be pH 5.5, 30 degrees C and at agitation of 120 rpm. The addition of MBC to soil had a greater impact on disappearance of hexazinone, which nearly increased fivefold over that of the control set. As a result, findings in the present investigation provide useful information for soil and water decontamination of hexazinone.
Key Laboratory of Pesticide and Chemical Biology, Ministry of Education College of Chemistry, Central China Normal University, 430079 Wuhan, China. zjuwxd@eyou.com
Xuedong
X
Wang
Sumei
S
Zhou
Huili
H
Wang
Shao
S
Yang
D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D004754:Enterobacter / Q000378:metabolism*; D052918:Environmental Restoration and Remediation; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D011549:Pseudomonas / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants; D013696:Temperature; D013997:Time Factors; D014227:Triazines / Q000737:chemistry*
D012989:Soil Pollutants; D014227:Triazines; C025641:hexazinone