一株高产碱性磷酸酶菌株的分离鉴定及其培养基配方优化
Isolation and identification of a high-yield Alkaline Phosphatase strain and its optimization of medium formula
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摘要: 为获得高产碱性磷酸酶微生物,采集土样进行筛选,并优化获得最佳产酶发酵条件。经过碱性磷酸酶筛选平板初筛和发酵复筛,分离得到一株优势产酶菌株。通过菌株形态观察、生理生化特征和分子生物学鉴定,确定该菌为醋杆菌奥尔兰亚种(Acetobacter orleanensis),编号S377。以碱性磷酸酶活力为响应值,在单因素实验的基础上,以果糖、尿素、pH、碳酸钙为实验因素,采用中心组合实验方法进行响应面优化设计。结果表明,最优发酵条件为果糖8.9 g/L,尿素0.4 g/L,碳酸钙4.5 g/L,初始pH9.2。利用该最优组合培养,碱性磷酸酶活性达到(28600±65)U,比优化前酶活力提高6.4倍。Acetobacter orleanensis S377产酶活力明显高于其它报道的产碱性磷酸酶微生物,为碱性磷酸酶生产提供了新的微生物资源,对该酶的工业化生产具有重要意义。Abstract: To obtain a strain with high Alkaline phosphatase activity from the soil,and to optimize the best fermentation conditions. A strain with high potential for secreting Alkaline phosphatase was isolated through Alkaline phosphatase reaction plate and fermentation screening. Based on strain morphology,physiological and biochemical characteristic and molecular biology assay,the strain has been identified as Acetobacter oriental S377. According to single factor experiment,taking the fructose,urea,calcium carbonate and pH as the experimental factors,the response surface test was optimized by the center combination experiment with the Alkaline phosphatase activity as the response value. The result revealed that the optimal fermentation conditions was fructose 8.9 g/L,urea 0.4 g/L,calcium carbonate 4.5 g/L and the initial pH9.2.The activity of Alkaline phosphatase of S377 could reach to(28600±65) U under the optimization conditions,which was approximately 6.4 times as that at the original culture conditions. The enzyme activity of S377 was significantly higher than that of other microorganisms reported,which provided a new microbial resource for the production of Alkaline phosphatase and was of great significance to the industrial production of this enzyme.