摘要
为了明确一株蜡状芽孢杆菌（Bacillus cereus HY-2）对毒死蜱的降解特性,在基础培养基中定量添加毒死蜱和降解菌进行混合摇培,每12 h取样检测毒死蜱残留量和菌株生长量,研究了接种量、毒死蜱初始质量浓度和含盐量等因素对菌株降解毒死蜱的影响。结果表明,接种量为8%（体积分数,接种体密度为OD600=3.0）时对80mg/L毒死蜱的降解率最高,为53%。随毒死蜱初始质量浓度增加,菌株的生长受到不同程度的抑制,然而随着毒死蜱的降解,菌体的生长量迅速增加,培养液的p H值随降解菌的增殖而逐渐上升。毒死蜱初始质量浓度为40~150 mg/L时,随降解时间延长,毒死蜱的残留质量浓度逐渐下降;而毒死蜱初始质量浓度为200 mg/L时,毒死蜱质量浓度在降解过程中出现了先上升后下降、然后逐渐下降的现象。降解菌对Na Cl有较高的耐受度,当Na Cl质量浓度为20~70 g/L时,降解菌在60 h时对80 mg/L毒死蜱的降解率为27%~53%。
This paper is oriented on how to characterize the effects of the influential factors on the cblorpyrifos degradation based on a new screened Bacillus cereus HY- 2 that enjoys the potentiality to biode- grade the chlorpyrifos in batch shake flasks. As is known, chlorpyri- fos is the key product of organic phosphorus pesticides that has been widely used in all the parts of China. However, it should never ig- nore the pollution it has brought about to the environment, for the mi- crobial degradation can serve as one of the most efficient ways to re- move pollution. It is just for the purpose of reducing the pollution that chlorpyrifos has brought about to the environment, we have conducted an experiment to test the residue of chlorpyrifos and the OD600 of the culture medium every 12 h so as to find the effects of the inoculation content, the initial chlorpyrifos concentration and the sodium chloride content on the biodegradation rate of chlorpyrifos and the growth of the strain. The results of our experiments have shown that it is possi- ble to increase the degradation rate of 80 mg/L chlorpyrifos up to its up limit of 53 % on the condition that the inoculation amount is set about 8% （ V~ V, inoculum density is OD600 = 3.0）. And then, with the increase of the initial concentration of chlorpyrifos, the growth of the strain could be possibly inhibited to the varying extents. Never- theless, with the degradation of chlorpyrifos, the amount of the bacte- ria may likely increase so fast as to reach its maximal limit with no chlorpyrifos added, but the pH value of the culture medium could be increasing while gradually speeding up the proliferation of the degrad- ing bacteria. We would like to propose that the initial concentration of chlorpyrifos should be kept at 40 - 150 mg/L, with the residue con- centration of the pesticide turning gradually to decrease with the ex- tension of the time. In contrast, the degradation features of 200 mg/L chlorpyrifos may reveal a tendency to increase first and decrease later during
出处
《安全与环境学报》
CAS
CSCD
北大核心
2015年第2期174-177,共4页
Journal of Safety and Environment
基金
安徽省高等学校省级自然科学研究一般项目(KJ2013B076)
安徽科技学院引进人才项目(ZRC2012326)
关键词
环境工程学
毒死蜱
蜡状芽孢杆菌
耐盐性
environmental engineering
chlorpyrifos
Bacilluscereus
salt tolerance
