Abstract: The acetochlor-contaminated soil could be repaired by microbial technology, and a high-efficient acetochlor-degrading bacterium named as Bacillus subtilus L3 has been obtained after a series of isolation, selection and identification. In order to further verifiy its actual degradation effects on acetochlor and its restoration effects on contaminated soil, the pot experiment was conducted in this paper. Firstly, this test inspected the effects of degraded bacteria concentration and the degraded time on the degradation of acetochlor in the soil, and secondly, of the application of strain L3 on the amount of indigenous microorganisms, enzyme activity, and nutrient elements in the soil, and on the growth of sensitive crop wheat. The results showed that the final concentration of bacterial liquid which had the highest degradation rate was 5×108 CFU/g soil, and its degradation rate was 92.65% after 50 d; the application of L3 bacteria liquid could recover the edaphon amount to a great degree; invertase activity, urease activity, protease activity and catalase activity increased respectively by 100%, 260%, 56% and 6%; total nitrogen content, rapid available phosphorus content, effective potassium content and the content of organic matter in soil increased respectively by 77%, 159%, 698% and 274%; compared with the control, wheat aerial part heightened 117%, the total fresh weight gained 56%, and root length grew by 27%. The results confirmed a good acetochlor-degrading effect and soil restoration capacity of strain L3, and laid a theoretical foundation for the practical application of strain L3 in soil pollution regulation and restoration.

Key words: acetochlor, degrading bacterium, Bacillus subtilis, potted effect, soil restoration

摘要： 应用微生物技术可以对乙草胺污染土壤进行修复，经前期分离筛选及鉴定，已获得高效乙草胺降解菌株Bacillus subtilus L3，为进一步明确其对乙草胺的实际降解效果及对污染土壤的修复作用，对L3开展盆栽效果研究。试验考察了不同降解菌浓度和施用时间对乙草胺降解率的影响，以及降解菌的施用对土壤中可培养的常见微生物数量、酶活、营养元素及敏感作物小麦生长的影响等。结果表明，终浓度为5×108 CFU/g土的菌液对乙草胺的降解率最高，50 d后对乙草胺的降解率为92.65%；施用L3菌液后，污染土壤微生物的数量有较大程度的恢复；蔗糖酶、脲酶、蛋白酶、过氧化氢酶活力分别提高100%、260%、56%与6%；土壤的全氮、速效磷、有效钾、有机质分别提高77%、159%、698%和274%；小麦地上部分较对照组增高117%，总鲜重增重56%，根长增长27%。该结果证实菌株L3具有良好的乙草胺降解效果和土壤修复能力，为该菌株在土壤污染治理及修复中的实际应用奠定了理论基础。

关键词: 乙草胺, 降解菌, 枯草芽孢杆菌, 盆栽效果, 土壤修复