摘要
采用室内培养方法,从长年施用乐果的土壤中分离筛选出一株能在高浓度乐果中生长且能以乐果为惟一碳源的细菌菌株L-39。结果表明,该菌株对乐果的平均降解量为1 306.33 mg.L-.160h-1。经鉴定,该菌株为铜绿假单胞菌(Pseudomonas aeruginosa),即绿脓杆菌。该菌株能耐受浓度达10 000 mg.L-1的乐果农药,其最适生长温度为28℃左右,在(18￣42)℃的广泛温度范围内仍生长良好,最适生长pH值为7.0左右,同样具有广泛的pH值生长范围(pH6.0￣9.0)。初步确定菌株L-39具有广谱的降解有机磷农药的能力,因其在基础培养基摇瓶培养中可降解辛硫磷446 mg.L-.15d-1,乙酰甲胺磷31 mg.L-.15d-1。田间小区试验表明,菌株L-d的液体摇瓶发酵菌制剂在土壤中有明显的有机磷农药降解效果(15.0 mg.kg-.17d-1),即乐果去除率为63.6%。
Pesticides play an important role in the success of modem farming and food production. However, the release of pesticides to the environment arising from non-approved use, poor practice, illegal operations or misuse is increasingly recognized as contributing to soil contamination. So, screening some microorganisms with high degrading ability becomes important. A bacteria strain named L-39 was isolated from soils polluted by dimethoate for many years. L-39 was identified as Pseudomonas aeruginosa, grew well in culture medium with very thick dimethoate but without any other C source, and could remove dimethoate 1 306.33 mg·L^-1· 60h^-1. The optimum growth conditions for L- 39 were about 28 ℃ and pH 7.0, with the maximum growth tolerance to dimethoate being 10 000 mg·L^-1, but it still grew well in 18-42 ℃ and pH6.0-pH9.0. Strain L-39 could also degrade phoxim（446 mg· L^-1·5d^-1） and acephate（31 mg· L^-1·5d^-1）, so its degradability was broadspectrum. The field experiments showed that L-39 had obvious effects on the removal of residual dimethoate in soil （15.0 mg·kg^-1·7d^-1, 63.6%）. All these results suggested that strain L-39 offered significant effects of degrading organophosphate pesticide.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2006年第5期1255-1259,共5页
Journal of Agro-Environment Science
基金
科技部"科技基础性工作和社会公益研究专项"(2004DIB3J073)
科技部"国家科技基础条件平台工作"(2004DKA30560)
关键词
乐果
生物修复
菌株
筛选
dimethoate
microbial remediation
bacteria strain
screening
