克雷伯氏菌胞外多糖的发酵培养基优化及乳化性质  

Medium Qptimization and Emulsifying Property of Exopolysaccharide Produced by Klebsiella sp. PHRC1. 001

作　　者：崔娜娜[1] 赵萌[1] 李娜[1] 戎瑜 方亚鹏[1] 

机构地区：[1]湖北工业大学轻工学部食品与制药工程学院,湖北武汉430068

出　　处：《安徽农业科学》2015年第21期38-42,共5页Journal of Anhui Agricultural Sciences

基　　金：国家优秀青年科学基金项目(31322043);湖北省高等学校优秀中青年科技创新团队计划(T201307);湖北省教育厅科学研究计划项目(Q20141401)

摘　　要：[目的]以克雷伯氏菌(Klebsiella sp.)PHRC1.001为发酵对象,优化该菌产胞外多糖的培养基组分,并初步评价了该多糖的乳化性质。[方法]以多糖粗产量为考察指标,采用单因素试验和正交试验法进行了发酵培养基组分优化,并通过发酵罐培养验证了优化培养基下的粗多糖产量。[结果]Klebsiella sp.PHRC1.001产胞外多糖的最优培养基为:蔗糖40 g/L,Ca Cl20.8 g/L,KNO32.5 g/L,Mg SO4·7H2O 9.0 g/L,Na H2PO43.5 g/L,起始p H 7.0,在此培养基条件下发酵罐最高粗糖产量达到21 g/L,约是初始培养基条件下的2.1倍。此外,以中链甘油三酸酯(MCT)为油相(20%),1%胞外多糖为乳化剂制备O/W乳液,通过激光粒度仪、光学显微镜和荧光显微镜表征乳液的粒径分布和颗粒形态,通过加速试验表征乳液储藏物理稳定性,结果发现,PHRC1.001多糖具有较好的乳化活性,该O/W乳液储藏物理稳定性高。[结论]Klebsiella sp.PHRC1.001为一株高产胞外多糖菌株,且该多糖具有良好的乳化活性,工业应用前景良好。Fermentation medium for a novel exopolysaccharide （EPS） from Klebsiella sp. PHRC1. 001 was optimized and emulsifying property of this exopolysaccharide was evaluated. [ Method ] Using EPS crude yield as the main index, the medium components of PHRC1.001 EPS fermentation were optimized through single factor and orthogonal test. [Result]The optimized medium consisted of 40 g/L sucrose, 0.8 g/L CaC12, 2.5 g/L KNO3, 9.0 g,/L MgSO4 ·7H2O and 3.5 g/L NaH2PO4 at pH 7.0. Fermentation in a 7 L fermentor using the optimized medium resulted in a maximum crude yield of 21 g/L, which was 2.1 fold of that using the initial medium. Using MCT as the oil phase （20% of the total volume）, the oil in water （O/W） emulsion stabilized by 1% PHRC1. 001 EPS was prepared. Size distribution and microscopy of O/W emulsion droplets were characterized using laser particle analyzer, optical microscope and fluorescence microscope. The physical stability of O/W emulsion was characterized by an acceleration test at high temperatures. PHRC1. 001 EPS showed a good emulsifying activity and the O/W emulsion was physically stable during storage. [ Conclusion] Klebsiella sp. PHRC1. 001 produced EPS at high yield and this EPS achieved a good emulsifying activity. Klebsiella sp. PHRC1. 001 provided a promising way to produce EPS with a high emulsifying activity in industrial scale.

关 键 词：胞外多糖 克雷伯氏菌 培养基优化 乳化性质 

分 类 号：S188[农业科学—农业基础科学]