氨基酸修饰可食用生物膜载体的制备与性质

Preparation and Properties of Edible Amino Acid-Modified Biofilm Carrier

为拓展乳酸菌生物膜在食品领域的应用,构建可食用型高分子载体,本实验以可介导乳酸菌黏附的氨基酸为配体,将其修饰在海藻酸钠材料上,通过核磁共振技术、氨基酸含量、ζ电势和水接触角等物理量表征载体性质,培养马奶酒样乳杆菌ZW3,研究载体对乳杆菌生长和胞外多糖分泌的促进作用。结果显示:培养4 d后,精氨酸修饰载体表面乳杆菌数量达到3.8×107 CFU/cm^2,是赖氨酸修饰载体的3.5倍;同时胞外多糖分泌量达到28.2μg/cm^2,是赖氨酸修饰载体的2.4倍。与赖氨酸修饰载体相比,精氨酸修饰载体更有利于乳杆菌的生长和胞外多糖的分泌。该结果表明可以通过配体种类的选择促进乳酸菌生物膜的形成。

In order to expand the application of lactic acid bacterial biofilm in the food industry and construct ediblefunctional carrier, amino acids which could be used as ligands for bacterial adhesion were modified onto alginate in thisstudy. The structures, compositions, electrical properties and hydrophilicity of the modified carriers （Alg-Arg and Alg-Lys）were characterized by nuclear magnetic resonance, amino acid content analysis, and ζ potential and water contact anglemeasurement. Lactobacillus kefiranofaciens ZW3 was cultured on the carriers to investigate its growth and extracellularexopolysaccharide secretion. The results showed that after cultivation for 4 d, the amount of ZW3 on Alg-Arg reached up to3.8 × 10^7 CFU/cm^2, which was 3.5 times as high as that on Alg-Lys. The secretion amount of extracellular exopolysaccharidewas 28.2 μg/cm^2, which was increased by 2.4 times in comparison with that on Alg-Lys. Compared with lysine-modifiedcarrier, arginine-modified carrier was better for ZW3 growth and the secretion of extracellular exopolysaccharide. Theseresults demonstrated that biofilm formation could be enhanced by the appropriate ligand.