【摘要】：微生物酯酶是一種廣泛應(yīng)用于食品、醫(yī)藥和精細化工等領(lǐng)域的工業(yè)化酶。為了豐富酯酶資源,本文通過提取我國傳統(tǒng)發(fā)酵食品環(huán)境樣品總基因組DNA,構(gòu)建宏基因組文庫,從中篩選獲得一個新的酯酶基因(est_115),該基因全長948 bp,編碼316個氨基酸,其蛋白序列同源性分析,表明與來自Pseudomonas lutea的羧酸酯水解酶同源性最高為38%,顯示酯酶Est_115屬于新的酯酶類。然后構(gòu)建了est_115基因重組表達載體,在大腸桿菌BL21(DE3)中獲得表達,經(jīng)純化得到重組酯酶Est_115。酶學(xué)性質(zhì)的分析表明,該重組酯酶Est_115對酰基碳鏈較短的對硝基苯酚酯具有較高的催化活性,最適作用溫度為35℃,最適p H值為7.0,在10%~18%Na Cl條件下,酶蛋白可保持較高的催化活性,具有良好的耐鹽性,提示該酶可以應(yīng)用在高滲透壓食品加工中,是一個新型的極具潛力的酯酶。
[Abstract]:Microbial esterase is an industrial enzyme widely used in food, medicine and fine chemical industry. In order to enrich esterase resources, a new esterase gene (est_115) was obtained by extracting total genomic DNA, from traditional fermented food environmental samples in China to construct macrogenomic library. The full length of the gene was 948 bp,. It encodes 316 amino acids and its protein sequence homology analysis shows that the homology with Carboxyester hydrolase from Pseudomonas lutea is up to 38%, indicating that esterase Est_115 belongs to a new esterase. Then the recombinant expression vector of est_115 gene was constructed and expressed in E. coli BL21 (DE3). The recombinant esterase Est_115. was purified. The analysis of enzyme properties showed that the recombinant esterase Est_115 had high catalytic activity for p-nitrophenol ester with short acyl carbon chain, the optimum reaction temperature was 35 鈩，

本文編號：2494115