耐丁草胺菌株BUT-6~T的筛选及其多相分类研究

发布时间：2018-04-03 03:15

  本文选题：新种　切入点：丁草胺　出处：《南京农业大学》2015年硕士论文

【摘要】：在世界范围内,氯代乙酰胺类除草剂受到广泛应用,而其中丁草胺(Butachlor)是亚洲范围内应用最广的苯乙酰胺除草剂,现已成为我国广泛使用的除草剂之一。目前丁草胺的用量不断增加,存在不合理地使用现象,伴随着其溶淋渗透作用,其对各种土壤、水体的生态副作用将日益显现。本研究从长期受丁草胺作用的污泥中分离到一株对丁草胺有很强耐受能力的细菌命名为BUT-6~T。本文全面系统地研究该菌株的各种生理、生化、遗传等特性。研究发现,在基础盐培养基中加入1250mg.L~(-1) 丁草胺,菌株BUT-6~T可仍然表现出有一定生长。菌株BUT-6~T的单细胞呈棒状大小为0.5-0.6×3.5-4.0 μm,革兰氏染色显阴性,无运动性鞭毛,不产生芽孢。在R2A培养基上于30℃培养3d后,菌落呈现黄色,表面凸起,近圆形,边缘有透光性。BUT-6~T生长需氧,当环境条件为30℃,1.0%NaCl,pH7.0时生长状况最佳。菌株BUT-6~T脂肪酸的主要成分为iso-C15:0,iso-C17 ω9c,和iso-C17:0(10%);主要极性脂种类有磷脂酰甲基乙醇胺、磷脂酰甘油、双磷脂酰甘油、一个未鉴定的氨磷脂还有3种未知的磷酸脂类;最主要的呼吸醌是泛醌,即Q-8。BUT-6~T 的 DNA G+C mol%含量为 71.7 mol%;与 BUT-6~T 的 16S rRNA 基因序列相似度最高的菌株是Tahibacter aquatiusPYM5-11T(98.6%);BUT-6~T与参考菌株Tahibacter aquaticus PYM5-11T 的 DNA-DNA 杂交同源性为 47.1 ± 0.71%,远低于新种鉴定阈值同源性70%。菌株BUT-6~T的过氧化氢酶、氧化酶、酪蛋白水解试验呈阴性;碱性磷酸酶、酯酶(C4、C8)、类酯酶(C14)、亮氨酸芳胺酶、缬氨酸芳胺酶、胱氨酸芳胺酶、胰蛋白酶反应呈阳性;半乳糖苷酶等反应呈阴性;七叶苷、明胶、尿素、吐温-80水解呈阳性;不产H2S和吲哚,也不能还原硝酸盐。BUT-6~T可以利用N-乙酰葡糖胺、癸酸、柠檬酸盐、苯乙酸盐、5-酮葡糖酸、苹果酸盐等物质作为碳源;不可以利用山梨醇、肌醇、苦杏仁苷、鼠李糖、蜜二糖、葡萄糖、甘露糖及阿拉伯糖进行发酵产酸;BUT-6~T抗壮观霉素、青霉素、左氟沙星、氨苄青霉素、氯霉素、头孢他啶等。综合以上对其诸多特征的详细分析,将菌株BUT-6~T鉴定为Tahibacter属中的一个新种,命名为Tahibactercaenisp.nov。
[Abstract]:In the world, chloroacetamide herbicides are widely used, among which butachloram is the most widely used phenylacetamide herbicides in Asia, and has become one of the most widely used herbicides in China.At present, the amount of butachlor is increasing, there is unreasonable use phenomenon, with its leaching and infiltration, the ecological side effects of butachlor on various soils and water bodies will become increasingly apparent.In this study, a bacterial strain with strong tolerance to butachlor was isolated from the sludge treated with butachlor for a long time.The physiological, biochemical and genetic characteristics of the strain were studied in this paper.It was found that the strain BUT-6~T could still grow when adding 1250 mg 路L ~ (-1) butachlor to the basic salt medium.The single cell size of the strain BUT-6~T was 0.5-0.6 脳 3.5-4.0 渭 m, which was negative for Gram staining and had no motility flagella and no spores.After being cultured on R2A medium at 30 鈩，

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