咪草烟污染土壤的微生物修复特性研究.docVIP

 咪草烟污染土壤的微生物修复特性研究# 金雷，成明根，黄星** （南京农业大学生命科学学院） 5 10 15 20 25 30 35 40 摘要：在实验室条件下，研究了降解菌 Bacillus sp. QC-13 对咪草烟污染土壤的生物修复作 用。投加降解菌 QC-13 可显著提高咪草烟在土壤中的降解速率。当咪草烟浓度为 50mg· kg-1 干土，QC-13 的接种量为 108 CFU g -1 干土时，第 21d 土壤中咪草烟的降解率为 66.2%，而 对照土壤中咪草烟的降解率为 14.4%。咪草烟的降解速率和接种量呈正相关，当接种量减少 为 105CFU g -1 干土时，降解率降低为 31.8%。随着土壤中咪草烟浓度升高，降解率则会降 低。土壤中咪草烟浓度达到 100 mg kg-1 时，投加降解菌后土壤中的咪草烟降解率仅为 38.7 %。QC-13 降解土壤中咪草烟的最适温度为 30，21 d 的降解率可达 62.7%。当土壤含 水量为 40%时，咪草烟的降解率为 62.2%，当含水量增加，降解率则降低。 关键词：环境微生物学；咪草烟；生物修复 中图分类号：S154.39 BIOREMEDIATION OF IMAZETHAPYR-CONTAMINATED SOIL JIN Lei, CHENG Minggen, HUANGX Xing (College of Life Sciences,Nanjing Agricultural University) Abstract: Bioremediation of imazethapyr contaminated soil with QC-13 was studied under laboratory conditions. Addition of QC-13 could prominently accelerate the degrading of imazethapyr in soil. When the concentration of imazethapyr was 50mg·kg-1, the inoculation of QC-13 was 108 CFU·g-1, degradation rate was 66.2% after 21 days, whereas the rate was only 14.4% in control group. Degradation rate was related positively to the amount of inoculation. When the inoculation of QC-13 was 105 CFU·g-1, the degradation rate was 31.8%. Low concentration of imazethapyr in soil was easily for QC-13 to degrade. When the concentration of imazethapyr increased to 100 mg·kg-1, imazethapyr degradation rate was only 38.7%. Soil temperature and moisture also affected imazethapyr degradation rate. When it was 30℃, the rate reached 62.7% in 21 days. When soil moisture was 40%, imazethapyr degradation rate was 62.2%, whereas when soil moisture was 50%, the rate decreased to 25.2%. Key words: Environmental microbiology; Imazethapyr; Bioremediation 0 引言 咪草烟是20世纪80年代美国氰胺公司开发的咪唑啉酮类除草剂，为乙酰乳酸合酶抑制剂 [1,2] 重要农药之一[3]。但咪草烟在土壤中残留期长，随着使用年限的延长，咪草烟残留污染农田 土壤，对后茬敏感作物产生药害，造成经济损失，同时导致大豆田轮作困难[4,5]。因此，咪 草烟在农田土壤中的降解与受污土壤的修复引起了科研工作者的广泛关注。 已有研究人员发现可利用TiO2悬浊液处理咪草烟残留。2002年，Elazzouzi M等人发现以 TiO2作为催化剂，能够提高咪草烟的降解效率[6]。2005年，Renata RI等人借助TiO2提高液体 中咪草烟的降解速率，4 h之内降解速度最高可以达到85%以上[7]。但该