摘要
为筛选富硒乳酸菌,利用其将无机硒转化为有机硒,用于开发富硒产品,实验以现存的15株乳酸菌为实验材料,将质量浓度为20μg/mL的硒加入MRS培养基中,检测菌体OD值筛选富硒菌;通过测定生长曲线和检测培养基中硒含量不同时的菌体密度来确定富硒菌合适的加硒时间和富硒浓度;使用3,3’-二氨基联苯胺(3,3’-DAB)比色法测定菌株富硒量;通过检测菌体抗氧化活性和耐胆盐、耐人工胃液的能力来评估富硒乳酸菌的体外活性以及在人体肠道内的生存能力。结果表明,从15株菌中筛出9株富硒菌,适宜的加硒时间为2 h,加硒浓度为40μg/mL,硒转化率最高的菌株是JX5,高达81.80%。9株菌富硒之后对自由基DPPH和ABTS的清除效果和耐胆盐和人工胃液的能力均呈现升高趋势,其中,菌株JX5在富硒之后对自由基DPPH和ABTS的清除率和耐胆盐和人工胃液的能力均显著升高,说明乳酸菌将无机硒转化为有机硒之后可提高菌体的体外活性。
Selenium-enriched(Se-enriched)lactic acid bacteria(LAB)can convert inorganic Se into organic one to produce new products.In this paper,Se-resistant LAB were screened out from 15 LAB by adding Se with a mass concentration of 20μg/mL to MRS medium and detecting the OD value.The appropriate Se adding time of Se-enriched LAB was determined by growth curve,and concentration was determined by cell density with different Se contents in the culture medium.The Se accumulation amount of LAB was measured through 3,3’-diaminobenzidine(3,3’-DAB)method.The in vitro activity of Se-enriched LAB and its survival ability in human intestinal tract were evaluated by detecting the antioxidant activity,bile salt resistance and artificial gastric fluid resistance of bacteria.Results showed that 9 Se-enriched LAB were screened out from 15,the appropriate addition time was 2 h,concentration was 40μg/mL,and the strain JX5 with the highest Se conversion rate was 81.80%.9 strains had different scavenging effects on free radicals DPPH and ABTS after Se enrichment,and had different abilities to resist bile salts and artificial gastric fluid,and the overall in vitro activity showed an increasing trend,especially strain JX5,increased significantly in four indexes,which indicated that the transformation of inorganic Se into organic one by LAB can improve the in vitro activity of bacteria.The antioxidant capacity and bile salt tolerance of 9 strains were improved to some extent.
作者
韦梦婷
王英
单成俊
刘小莉
夏秀东
董明盛
周剑忠
WEI Mengting;WANG Ying;SHAN Chengjun;LIU Xiaoli;XIA Xiudong;DONG Mingsheng;ZHOU Jianzhong(College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095,China;Institute Agro-Product Processing,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China)
出处
《食品工业科技》
CAS
北大核心
2021年第8期102-108,共7页
Science and Technology of Food Industry
基金
农业自主创新基金CX(18)2017
江苏省科技计划:BE2019307。
关键词
富硒
乳酸菌
筛选
富硒率
抗氧化能力
selenium enrichment
lactic acid bacteria
selection
selenium enrichment rate
antioxidant activity
