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目的对一株海洋来源的产海藻糖合成酶菌株进行鉴定及产酶条件的初步优化。方法通过16S rDNA基因序列的同源性分析,对一株来源于东海海水的海藻糖合成酶产生菌进行鉴定,并通过单因素分析初步研究其培养特性和最佳的发酵条件。结果该菌16S rDNA序列与GenBank中已知序列相比,最高相似度为100%,鉴定为假单胞菌属(Pseudomonas),命名为Pseudomonas sp.A50。其最佳碳源和氮源分别为2%麦芽糖和0.5%酵母膏,最佳NaCl浓度为2.5%,在初始pH 7.8,接种量1%,装液量125 mL/250mL,28℃,130 r/min发酵48 h,海藻糖合成酶活力达到最高。结论此产海藻糖合成酶菌株为假单胞菌属,优化后,海藻糖合成酶活力达到14.16 U/mL。
Objective To identify a marine strain of trehalose synthase and to optimize the conditions of its production. Methods A strain of trehalose synthase producing bacteria from seawater in the East China Sea was identified by homology analysis of 16S rDNA gene sequence. The culture characteristics and the optimum fermentation conditions were studied by single factor analysis. Results The 16S rDNA sequence of this strain had the highest similarity of 100% with the known sequence in GenBank. It was identified as Pseudomonas and named Pseudomonas sp. A50. The optimal carbon source and nitrogen source were 2% maltose and 0.5% yeast extract respectively. The optimal NaCl concentration was 2.5%. The optimal conditions were as follows: initial pH 7.8, inoculum size 1%, liquid volume 125 mL / 250 mL, 28 ℃, 130 r 48 h after fermentation, trehalose synthase reached the highest level. Conclusion The strain producing trehalose synthase is Pseudomonas, and the optimized trehalose synthase activity reaches 14.16 U / mL.