极端污染环境草甘膦抗性菌株的分离、鉴定及特性

Isolation and characterization of a new glyphosate-resistant strain from extremely polluted environment

摘要:

【目的】筛选高抗草甘膦菌株并对其进行鉴定和特性研究。【方法】从草甘膦极端污染土壤中分离高抗草甘膦菌株，并检测其草甘膦耐受能力，最适生长pH和抗生素抗性。通过生理生化特征和分子生物学特征的测定对该菌株进行鉴定。【结果】从草甘膦极端污染土壤中分离到一株高抗草甘膦的菌株SL06500，该菌株最高耐受草甘膦浓度为500 mmol/L，并且在200~500 mmol/L之间，菌株生长迅速，最适生长pH为4.0，具有氨苄青霉素、卡那霉素、四环素和氯霉素抗性。用16S rDNA的通用引物，经PCR扩增、测序得到SL06500的16S rDNA序列，该序列在GenBank的登录号为EU006066。将此序列经NCBI Blast进行核苷酸比对发现SL06500与无色杆菌属（Achromobacter）和产碱杆菌属（Alcaligenes）的Identity值均为99%。按照1994年版伯杰氏鉴定细菌学手册的命名规则，结合生理生化指标测定的结果，将菌株命名为木糖氧化产碱杆菌木糖氧化亚种SL06500 (Alcaligenes xylosoxidans subsp.xylosoxidans SL06500)。【结论】该菌株的较高草甘膦抗性和嗜药性的特点值得我们进行进一步的研究。更重要的是，这是首次关于木糖氧化产碱杆菌木糖氧化亚种草甘膦抗性的报道。

Abstract:

[Objective] To isolate and characterize a glyphosate-resistant strain from extremely polluted environment. [Methods] A glyphosate-resistant strain was isolated from extremely polluted soil taking glyphosate as the selection pressure. Its glyphosate resistance, growth optimal pH and antibiotic sensitivity were detected. Its morphology, cultural characteristics, physiological and biochemical properties, chemotaxonomy and 16S rDNA sequences were studied. Based on these results, the strain was identified according to the ninth edition of Bergey’s manual of determinative bacteriology. [Results] The isolate was named SL06500. It could grow in M9 minimal medium containing up to 500 mmol/L glyphosate. The cell growth optimal pH of SL06500 was 4.0. It was resistant to ampicillin, kanamycin, tetracycline and chloromycetin. The 16S rDNA of SL06500 was amplified by PCR and sequenced. Compared with the published nucleotide sequence of 16S rDNA in NCBI(National Center for Biotechnology Information), SL06500 showed high identity with Achromobacter and Alcaligenes. Based on morphological, physiological and biochemical characteristics, the strain was identified as Alcaligenes xylosoxidans subsp.xylosoxidans SL06500 according to the ninth edition of Bergey’s manual of determinative bacteriology. [Conclusion] Strain SL06500 is worthy to be studied because of its high glyphosate resistance.