摘要
通过研究和比较2株乳酸菌——植物乳杆菌D28(Lactobacillus plantarum D28)和粪肠球菌B21(Enterococcus faecium B21)的生长曲线,对Na Cl和胆盐的耐受性,对人工胃液和人工肠液的耐受性,以及它们的体外抗氧化能力和胆盐水解酶活性,判断其是否具有益生菌特性,以期为后期菌株功能研究提供理论基础。生长曲线试验表明,L.plantarum D28的最大生长速度出现在18 h左右,而E.faecium B21为16 h左右。起始pH对2株菌生长的影响很大,L.plantarum D28的最适生长pH为5.5~7.0,而E.faecium B21为pH 6.0~7.0。耐受性试验表明:E.faecium B21对Na Cl和胆盐的耐受性较好,高于L.plantarum D28;L.plantarum D28在人工胃液(pH 2.0,180 min)和人工肠液(pH8.0,240 min)中的菌群存活率均显著高于E.faecium B21。采用DPPH(二苯基苦基苯肼)自由基清除率来测定2株菌的体外抗氧化活性,结果表明,2株菌均具有一定的抗氧化活性,且L.plantarum D28的抗氧化活性(34.86%)显著高于B21(25.32%)。采用茚三酮法测定菌株的胆盐水解酶活性发现,E.faecium B21的胆盐水解酶活性(0.415 U/mg)显著高于L.plantarum D28(0.114 U/mg)。综上表明,L.plantarum D28和E.faecium B21均具有一定的益生特性,且这2个菌株均可应用于乳酸菌降低胆固醇活性的研究,且L.plantarum D28还可以用于应用乳酸菌提高体内抗氧化活性的进一步研究中。
Sunnnary Probiotics are defined as ＂living micro-organisms which, upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition＂. Recent reports have confirmed that probiotics can provide a variety of beneficial health effects, which are strain dependent. The regulation effect of probiotics was based on tolerance of acid environment in the stomach, and resistance to bile salt and trypsin in the small intestine. Most of lactic acid bacteria （LAB） are considered as probiotics, and have been widely used as dietary additives in cultured dairy foods and other fermentation products. The source of LAB may be naturally fermented food or human and animal intestines. In this study, two strains were isolated from Chinese traditional food （Northeast pickle and stinky beans）, and identified as Lactobacill plantarum D28 and Enterococcus faecium B21 by 16S rRNA gene sequences, respectively. The growth and potential probiotic characteristics of the two lactic acid bacteria strains were further investigated. Growth curve and the effect of initial pH on the growth were studied by speetrophotometry method. Meanwhile, the resistance characteristics were investigated, including sodium chloride （NaC1）, bile salt, artificial gastric juice and artificial intestinal juice. In addition, antioxidant activity and bile salt hydrelase activity （BSH） in vitro were determined by scavenging DPPH （2, 2-diphenyl-l-picrylhydrazyl） free radical and ninhydrin method, respectively. The results of growth cuwe showed that the growth rate of L. plantarum D28 was faster than E. faecium B21 under the same culture condition, and the stationary growth phase of h plantarum D28 and E. faecium B21 occurred at 18 h and 16 h, respectively. The growth rate of the two strains was affected by different initial pH; pH ranges of 5.5-7.0 and 6.0-7.0 were most favorite initial pH for L. plantarum D28 and E. faecium B21, respectively. Moreover, L. plantarum D28 had a good tolerance against NaC1 （5%） and bile salt �
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2017年第2期239-246,共8页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
上海市科委项目(B-9500-10-0004)
关键词
乳酸菌
生长特性
抗氧化活性
胆盐水解酶活性
lactic acid bacteria
growth characteristics
antioxidant activity
bile salt hydrolase activity
