不同瑞士乳杆菌发酵牛乳产肽的比较研究

Production Comparison of Small Peptides in Milk Fermented by Different Strains of Lactobacillus helveticus

为了从3株瑞士乳杆菌(JCM1120、CICC 6024和实验室保存菌株L0906)中筛选出1株产肽丰富的瑞士乳杆菌作为后续实验用菌株。采用水解度、pH值、小肽含量3个指标设计实验。结果表明:产酸能力最强的菌株CICC 6024在相同发酵过程中最大水解度明显高于其他菌株;菌株CICC 6024和菌株JCM1120的小肽含量在发酵时间16h处达到最大,菌株L0906的发酵活性较为缓慢,在发酵时间28h尚未达到顶峰;另外小肽的反相液相色谱峰图显示,菌株16h时CICC 6024菌对应的20mAU以上的小肽峰多达19个。通过比较,最后选定CICC 6024菌株作为后续实验用菌株,发酵时间为16h。

Three Lactobacillus helveticus strains（JCM1120,CICC6024 and L0906） were individually used to ferment fat-free milk powder.During 30 hours of fermentation,the changes in degree of hydrolysis（DH）,pH and number of small peptides were examined periodically.The results indicated that CICC6024 strain had the strongest acid-producing ability and resulted in the highest maximum DH and the contents of small peptides in milk fermented by Lactobacillus helveticu CICC6024 and JCM1120 both reached their maximum amounts at 16 h;however,the fermentation activity of L0906 strain was relatively lower and still did not reach the peak at 28 h.In addition,19 peaks with height of more than 20 mAU were observed in the RP-HPLC profile of the 16 h fermentation product of stain CICC6024.These investigations suggest that CICC6024 is an optimal strain for the production of small peptides derived from fermented milk and the optimal fermentation period is 16 h.