摘要
酵母菌胞外多糖(Exopolysaccharides,EPS)具有提高机体免疫力、抗氧化、抗肿瘤和降胆固醇等良好的功能特性,广泛应用在食品和医药等领域。为了丰富高产EPS酵母菌的菌株来源,从实验室保藏的10株酵母菌中筛选出一株高产EPS酵母菌Y3,并通过形态特征、生理生化特征和18S rDNA序列分析进行了鉴定。然后,探究其pH和胆盐耐受能力,利用单因素试验优化培养基组分和发酵条件。研究表明,酿酒酵母(Saccharomyces cerevisiae,S.cerevisiae)Y3初产量最高,为(3.27±0.22)g·L^(-1)。菌株在pH为3.0~8.0时,有20%以上的存活率,胆盐浓度为0.3%时,仍有(18.12±3.36)%的存活率,具有良好的体内益生菌应用潜力。S.cerevisiae Y3在蔗糖7%、酵母浸粉0.2%、氯化铵0.15%、磷酸二氢钾0.15%、氯化钙0.02%、接种量2%、初始pH 7、140 r·min^(-1)、30℃条件下培养144 h时,EPS产量达到(4.34±0.32)g·L^(-1),是优化前的2.30倍。研究结果为S.cerevisiae Y3作为益生菌的应用提供了依据,也为该菌株EPS规模化工业生产奠定了基础。
Yeast exopolysaccharides(EPS)are widely used in food and medicine fields because of their good functional properties such as enhancing immunity,antioxidation,anti-tumor and cholesterol lowering.In order to enrich the source of EPS-producing yeast strains,one high-yield EPS yeast strain Y3 was selected from ten yeast strains preserved in the laboratory.Strain Y3 was identified through morphological characteristics,physiological and biochemical characteristics as well as 18S rDNA sequence analysis.Then its pH and bile salt tolerance ability was explored,and the culture medium components and fermentation conditions were optimized by single factor test.The results showed that the initial EPS yield of Saccharomyces cerevisiae(S.cerevisiae)Y3 was(3.27±0.22)g·L^(-1) which was the highest among the ten testing strains.The survival rate of S.cerevisiae Y3 under pH 3.0~8.0 was more than 20%.Meanwhile,almost(18.12±3.36)%survival rate was obtained when the concentration of bile salt was 0.3%.These results collectively suggested a good application potential of probiotics in vivo.The EPS yield of S.cerevisiae Y3 reached(4.34±0.32)g·L^(-1) under the conditions of sucrose 7%,yeast extract 0.2%,ammonium chloride 0.15%,potassium dihydrogen phosphate 0.15%,calcium chloride 0.02%,inoculum 2%,initial pH 7,140 r·min^(-2) and 30℃ for 144 h,which was 2.30 times of that before optimization.The results provide a basis for the application of S.cerevisiae Y3 as a probiotic and lay a foundation for the large-scale industrial production of EPS.
作者
刘丽娜
杜仁鹏
徐家菊
赵丹
LIU Lina;DU Renpeng;XU Jiaju;ZHAO Dan(Key Laboratory of Microbiology,College of Heilongjiang Province,School of Life Sciences,Heilongjiang University,Harbin 150080,China;Engineering Research Center of Agricultural Microbiology Technology,Ministry of Education,Heilongjiang University,Harbin 150500,China;Guangxi Key Laboratory for Polysaccharide Materials and Modifications,School of Marine Sciences and Biotechnology,Guangxi University for Nationalities,Nanning 530008,China)
出处
《黑龙江大学自然科学学报》
CAS
2023年第2期199-208,共10页
Journal of Natural Science of Heilongjiang University
基金
国家自然科学基金(32072189,32071519)
黑龙江省高等学校基本科研业务费科技创新类专项(KJCX201921)
黑龙江省博士后科研启动金项目(LBH-Q18105)
广西多糖材料与改性重点实验室开放基金(GXPSMM20-2)。
关键词
酿酒酵母
胞外多糖
筛选
鉴定
单因素试验
saccharomyces cerevisiae
exopolysaccharide
screening
identification
single factor test
