乳杆菌源抗菌肽的代谢条件优化及其特性研究

探讨乳杆菌代谢产抗菌肽的条件及其生物学特性。通过琼脂扩散法分析嗜酸乳杆菌、干酪乳杆菌和发酵乳杆菌抑菌活性差异,采用正交实验分析获得干酪乳杆菌代谢产抗菌肽的最佳条件为:装液量20%、接种量2%、培养温度30℃,静置培养42h。研究发现该抑菌物质热稳定性好,在低p H条件下能够保持较好的抑菌活性,可被胰蛋白酶、中性蛋白酶和木瓜蛋白酶酶解而不被胃蛋白酶酶解。进一步的研究发现,该抑菌物质的作用方式为杀菌,且抑菌谱广,可抑制或杀灭多种革兰氏阴性菌和部分革兰氏阳性菌,对多种食源性病原菌有较强的抗性,其可开发为食品防腐剂和用于畜禽养殖的饲料添加剂。 

Study on optimization of metabolic conditions for bacteriocin production from Lactobacillus and its antimicrobial characteristics

To investigate metabolic conditions for bacteriocin production from Lactobacillus and its biological characteristics. The antimicrobial activity of the cell- free supernatant ( CFS) of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus fermentum was investigated by the agar diffusion assay.The results of orthogonal tests showed: when Lactobacillus casei was cultured for 42 h at 30℃ in the conditions of liquid volume of 20% and inoculum dose of 2%, the antimicrobial activity of the CFS came to the highest. The CFS of Lactobacillus casei culture was heat- stable, could maintain good antimicrobial activity at low p H conditions and was found to be sensitive to proteolytic enzymes such as trypsin, neutral protease and papain, but not pepsin. The action mode of the CFS was confirmed as bactericidal.The CFS showed a broad spectrum of antimicrobial activity against various species of gram- negative bacteria and some gram- positive bacteria, and also had a strong resistance to a variety of food- borne pathogens.These data showed, it could be developed as a feed additive for livestock and poultry breeding or natural food preservative for the food industry.