麦草畏降解菌株Ochrobactrum sp.3-3的分离鉴定及其降解特性

发布时间：2018-03-08 14:50

  本文选题：麦草畏　切入点：生物降解　出处：《应用与环境生物学报》2017年02期 　论文类型：期刊论文

【摘要】：麦草畏是理想的抗除草剂转基因工程的靶标除草剂;发掘新的麦草畏高效降解菌株和基因具有非常重要的理论和应用价值.从南京土壤样品中分离到一株麦草畏高效降解菌株,命名为3-3.根据生理生化特征和16S r DNA序列相似性分析,将其初步鉴定为苍白杆菌属(Ochrobactrum sp.).菌株3-3在48 h内完全降解100 mg/L的麦草畏.该菌株降解麦草畏的最适温度为30℃,最适p H为7.0.代谢产物高效液相和质谱鉴定结果表明该菌株降解麦草畏的起始步骤是脱甲基,形成没有除草活性的3,6-二氯水杨酸(DCSA).菌株粗酶液只在NADH存在时才有麦草畏脱甲基酶活性.PCR扩增和该菌基因组生物信息学分析表明该菌株没有已报道的麦草畏脱甲基酶基因DMO、Mtv及Dmt或其同源序列.总之,本研究首次分离筛选到苍白杆菌属的麦草畏降解菌,且该菌可能存在一个新的氧化酶类麦草畏脱甲基酶基因.
[Abstract]:Is the ideal target of herbicide dicamba herbicide resistant transgenic engineering; it has a very important theoretical and application value to explore the efficient degradation of dicamba strains and new genes isolated from Nanjing soil samples. The strain of dicamba degrading strains, named as 3-3. 16S according to the physiological and biochemical characteristics and R DNA sequence similarity analysis, the preliminary identification as Ochrobactrum (Ochrobactrum sp.). 3-3 strains of dicamba completely degraded 100 mg/L within 48 h. The optimum temperature is 30 DEG C the degradation of dicamba, the optimum P H 7.0. metabolites of HPLC and mass spectrometry identification results show that the initial steps of the degradation of dicamba is demethylated, formation of 3,6- chlorine no herbicidal activity two salicylic acid (DCSA) strains. The crude enzyme only in the presence of NADH have dicamba demethylase activity of the bacteria genome.PCR amplification and bioinformatics analysis showed that the There were no reported dicamba demethylase gene DMO, Mtv and Dmt and its homologous sequences. In short, this is the first study to isolated dicamba degrading bacteria Ochrobactrum, bacteria and the possible presence of a new enzyme dicamba demethylase gene.

【作者单位】： 南京农业大学生命科学学院 农业部农业环境微生物工程重点开放实验室;
【基金】：国家自然科学基金项目(3157010 5) 教育部新世纪优秀人才项目(NCET-13-0861)资助~~
【分类号】：X172;X592
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