咪唑烟酸高效降解菌的降解特性

The degradation characteristics of highly effecient degradation bacteria of imazapyr

从长期使用咪唑烟酸的非耕地土壤中,分离出两株高效降解菌ZJX-5和ZJX-9,经鉴定,分别为荧光假单胞菌Ⅱ型(pseudomonas fluorescenes biotypeⅡ)和腊状芽孢杆菌(Bacillus cereus).当咪唑烟酸的原始浓度为100mg/L,两株降解菌在2d内对其降解率均达70%以上.研究了单一菌株和混合菌株对咪唑烟酸的降解能力,结果表明,混合菌的降解能力明显优于单一菌株,尤其在咪唑烟酸浓度较高时,混合菌在降解率及耐性方面均比单一菌株明显提高.此外,外界环境条件对降解菌的活性也有显著的影响,当温度在30℃左右,反应液的pH值及降解菌的生物量越高,咪唑烟酸的原始浓度在低于适宜降解最高浓度(200mg/L)的情况下,降解菌的活性较强,对咪唑烟酸的降解较快.

Two strains of highly efferent degradation bacteria (ZJX-5, ZJX-9) were isolated from non-cultivated land soil in which imazapyr had been used for a long time; and were identified as pseudomonas fluorescenes biotypeⅡ and Bacillus cereus. They could degrade in 2d over 70% imazapyr when the original concentration of imazapyr was 100mg/L. The degradation ability of separated single strains and mixed strain on imazapyr were studied; and the results showed that the degradation ability of the mixed strain is superior distinctly to the separated single strains, especially in higher concentration of imazapyr, the degradation rate and resistance of the noised strain raised markedly as compared with the separated single strains. In addition, the activity of degradation bacteria was also affected markedly by outer circumstance conditions, which expressed that the activity of degradation bacteria was stronger with quicker degradation of imazapyr, at temperature about 30℃, higher pH of reaction liquor and higher biomass of degradation bacteria, and imazapyr original concentration less than 200mg/L.