The Study of Food-Grade Induced Expression and Enzymatic Properties of L-Arabinose Isomerase from Lactobacillus plantarum WU14 with High D-Tagatose Yield  

作　　者：Xiaoyu Chang Bi Ying Yanli Zhang Huifang Cao Tong Zhou Ping’an Zhong Bo Xu Xiaoyu Chang;Bi Ying;Yanli Zhang;Huifang Cao;Tong Zhou;Ping’an Zhong;Bo Xu(Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China)

机构地区：[1]Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China

出　　处：《Food and Nutrition Sciences》2016年第4期320-337,共18页食品与营养科学（英文）

摘　　要：L-arabinose isomerase (L-AI) is the key enzyme for D-galactose isomerization of D-tagatose by biological method. In this research, Lactobacillus plantarum WU14 with high D-tagatose yield was identified as Lactobacillus plantarum was isolated from the number of lactic acid bacteria from pickled vegetables. The crude L-arabinose isomerase activity of Lactobacillus plantarum WU14 with high D-tagatose yield was 13.95 U/mL under the optimal temperature 60&degC, pH 7.17 and substrate concentration 0.8 mol/L, and the conversion rate of 56.12% could be gained after 28 hours. Protein structure and specific of L-Arabinose Isomerase of Lactobacillus plantarum WU14 were researched. The results showed that L-arabinose isomerase is mainly composed of alpha helix and random coil. Then the recombinant L-AI gene was inserted into the food-grade expression vector pRNA48 and expressed in L. lactis NZ9000 successfully. The target protein expression reached the maximum amount when the induced concentration of nisin reaches 30 ng/mL after 12 h. And the crude enzyme activity of recombinant bacteria reached 6.21 U/mL under 60&degC. Otherwise the optimal conversion rate recombinant of L. lactis NZ9000/pRNA48-L-AI can reach 39.21% under the temperature of 50&degC, pH 7.17 and D-galactose concentration was 0.6 mol/L.L-arabinose isomerase (L-AI) is the key enzyme for D-galactose isomerization of D-tagatose by biological method. In this research, Lactobacillus plantarum WU14 with high D-tagatose yield was identified as Lactobacillus plantarum was isolated from the number of lactic acid bacteria from pickled vegetables. The crude L-arabinose isomerase activity of Lactobacillus plantarum WU14 with high D-tagatose yield was 13.95 U/mL under the optimal temperature 60&degC, pH 7.17 and substrate concentration 0.8 mol/L, and the conversion rate of 56.12% could be gained after 28 hours. Protein structure and specific of L-Arabinose Isomerase of Lactobacillus plantarum WU14 were researched. The results showed that L-arabinose isomerase is mainly composed of alpha helix and random coil. Then the recombinant L-AI gene was inserted into the food-grade expression vector pRNA48 and expressed in L. lactis NZ9000 successfully. The target protein expression reached the maximum amount when the induced concentration of nisin reaches 30 ng/mL after 12 h. And the crude enzyme activity of recombinant bacteria reached 6.21 U/mL under 60&degC. Otherwise the optimal conversion rate recombinant of L. lactis NZ9000/pRNA48-L-AI can reach 39.21% under the temperature of 50&degC, pH 7.17 and D-galactose concentration was 0.6 mol/L.

关 键 词：D-TAGATOSE Lactobacillus plantarum WU14 L-Arabinose Isomerase Recombinant PCR Technology Food-Grade Expression 

分 类 号：TQ4[化学工程]