Mu Guangqing, Zhang Zhao, Wang Jiayi, Jiang Shujuan, Wang Hongxin, Xu Yunpeng, Li Xinling, Chi Lei, Li Yue, Tuo Yanfeng, Zhu Xuemei
School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
Xinjiang Tianrun Biological Technology Co., Ltd., Urumchi 830011, China.
Foods. 2021 Dec 29;11(1):88. doi: 10.3390/foods11010088.
α-Casein (α-CN) is considered the main allergen in bovine milk. Lactic acid bacteria (LAB) fermentation can hydrolyze milk protein and therefore reduce the antigenicity. In this paper, a LAB reducing the antigenicity of casein, identified as 7-2 ( 7-2), was primarily identified by screening for protein hydrolysis ability using a method involving the determination of released free amino acid with further selection for the ideal antigenicity-reducing capability by enzyme-linked immunosorbent assay (ELISA). In order to verify the capability of 7-2 in inhibiting antigenicity, the standard milk proteins α-LA, β-LG, α-CN, β-CN and κ-CN were cultured with 7-2 for 18 h; The results of SDS-PAGE show that all the bands corresponding to the full length tested proteins became unclear or completely disappeared indicating that these proteins were hydrolyzed by 7-2. Correspondingly, the antigenicities of α-CN and β-LG were significantly reduced. 7-2 demonstrated negative hemolysis and nitrate reductase capabilities and was sensitive to the commonly used antibiotics ampicillin clindamycin tetracycline chloramphenicol, and erythromycin, demonstrating that 7-2 could be used in dairy product fermentation to reduce the antigenicity of milk protein.
α-酪蛋白（α-CN）被认为是牛奶中的主要过敏原。乳酸菌（LAB）发酵可以水解牛奶蛋白，从而降低其抗原性。本文通过一种涉及测定释放的游离氨基酸的方法筛选蛋白水解能力，并进一步通过酶联免疫吸附测定（ELISA）选择理想的抗原性降低能力，初步鉴定出一种能降低酪蛋白抗原性的乳酸菌，命名为7-2。为了验证7-2抑制抗原性的能力，将标准牛奶蛋白α-乳白蛋白（α-LA）、β-乳球蛋白（β-LG）、α-CN、β-CN和κ-CN与7-2培养18小时；十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）结果表明，所有与测试全长蛋白相对应的条带均变模糊或完全消失，表明这些蛋白被7-2水解。相应地，α-CN和β-LG的抗原性显著降低。7-2表现出阴性溶血和硝酸还原酶能力，并且对常用抗生素氨苄青霉素、克林霉素、四环素、氯霉素和红霉素敏感，表明7-2可用于乳制品发酵以降低牛奶蛋白的抗原性。
