Enhanced extracellular production of alpha-lactalbumin from Bacillus subtilis through signal peptide and promoter screening  

作　　者：Yuqi Zhu Pengdong Sun Chunjian Li Yu Zhang Yu Wang Jingyuan Li Yanfeng Liu Jian Chen Yang Deng 

机构地区：[1]College of Food Science and Engineering,Qingdao Agricultural University,Qingdao 266109,China [2]Key Laboratory of Special Food Processing(Co-construction by Ministry and Province),Ministry of Agriculture Rural Affairs,Qingdao Agricultural University,Qingdao 266109,China [3]Qingdao Special Food Research Institute,Qingdao 266109,China [4]Science Center for Future Foods,Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology,Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology,Jiangnan University,Wuxi 214122,China [5]Key Laboratory of Carbohydrate Chemistry and Biotechnology,Ministry of Education,School of Biotechnology,Jiangnan University,Wuxi 214122,China

出　　处：《Food Science and Human Wellness》2024年第4期2310-2316,共7页食品科学与人类健康（英文）

基　　金：This work was funded by National Natural Science Foundation of China(32272279);the Key R&D project of Qingdao Science and Technology Plan(22-3-3-hygg-29-hy).

摘　　要：Alpha-lactalbumin(α-LA)is a major whey protein found in breast milk and plays a crucial role in the growth and development of infants.In this study,Bacillus subtilis RIK1285 harboring AprE signal peptide(SP)was selected as the original strain for the production ofα-LA.It was found thatα-LA was identified in the pellet after ultrasonic disruption and centrifugation instead of in the fermentation supernatant.The original strain most likely only producedα-LA intracellular,but not extracellular.To improve the expression and secretion ofα-LA in RIK1285,a library of 173 homologous SPs from the B.subtilis 168 genome was fused with target LALBA gene in the pBE-S vector and expressed extracellularly in RIK1285.SP YjcN was determined to be the best signal peptide.Bands in supernatant were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and purified by nickel column to calculate the highest yield signal peptide.In addition,different promoters(P_(aprE),P_(43),and P_(glv))were compared and applied.The results indicated that the strain RIK1285-pBE-P_(glv)-YjcN-LALBA had the highestα-LA yield,reaching 122.04μg/mL.This study demonstrates successful expression and secretion of humanα-LA in B.subtilis and establishes a foundation for simulating breast milk for infant formulas and developing bioengineered milk.

关 键 词：Bacillus subtilis ALPHA-LACTALBUMIN Bioengineering milk Signal peptide Promoter screening 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]