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【目的】分离获得一株能有效降解乙草胺的菌株,并研究其降解乙草胺的影响因素,为乙草胺生物修复提供微生物资源。【方法】通过富集培养和分离培养,从样品中筛选能以乙草胺为唯一碳氮源的菌株。通过划线培养获得单菌落,并采用革兰氏染色法和16S r RNA基因测序进行菌株的初步鉴定和系统分类。通过单因素试验研究初始乙草胺浓度、外加碳氮源对其降解乙草胺的影响,并基于正交设计进行优化。【结果】分离获得的一株菌为革兰氏阴性菌,初步确定为Pseudomonas sp.,能有效利用乙草胺进行生长。单因素试验证明在乙草胺初始浓度为10 mg/L时降解率最高;外加碳氮源能提高乙草胺降解率,其中葡萄糖和蛋白胨分别最为有效。正交设计表明在最优条件下,其对乙草胺降解率可以达到80.2%。【结论】菌株A-1能有效利用乙草胺进行生长,其降解乙草胺受多种因素影响。本研究将为利用进行该菌株进行乙草胺污染修复提供菌种资源。
【OBJECTIVE】 To isolate and obtain a strain that can effectively degrade acetochlor and study its influencing factors on acetochlor degradation to provide microbial resources for the bioremediation of acetochlor. 【Method】 Through enrichment culture and isolation and culture, the strains that could utilize acetochlor as sole carbon and nitrogen source were screened from the samples. Single colonies were obtained by scribing culture, and preliminary identification and phylogenetic analysis of strains were carried out by Gram stain and 16S rRNA gene sequencing. The initial acetochlor concentration and the effect of carbon and nitrogen sources on the degradation of acetochlor were studied by single factor experiments and optimized based on orthogonal design. 【Result】 The isolated strain was Gram-negative bacteria, initially identified as Pseudomonas sp., Which could effectively utilize acetochlor to grow. The single factor test showed that the degradation rate of acetochlor was the highest when the initial concentration of acetochlor was 10 mg / L. The addition of carbon and nitrogen sources could increase the degradation rate of acetochlor, of which glucose and peptone were the most effective. Orthogonal design showed that under the optimum conditions, the degradation rate of acetochlor can reach 80.2%. 【Conclusion】 Acetochlor can be used effectively for growth of strain A-1, and its degradation of acetochlor is influenced by many factors. This study will provide bacteria resources for the acetochlor pollution repair using this strain.