类干酪乳酪杆菌PC-01的鉴定和生物学特性及其在活菌型乳酸菌饮料中的应用

Identification and Biological Characteristics of Lacticaseibacillus paracasei PC-01 and Its Application in Live-bacteria Beverage

目的:以菌株PC-01为研究对象,从多相鉴定、生物学特性及其发酵活菌型乳酸菌饮料的产品特性方面研究和评价该菌株。方法:通过菌株形态学、生理生化结合全基因组测序对菌株PC-01进行菌种水平的鉴定;通过菌株在不同温度、pH值下生长情况及其对不同碳、氮源利用能力方面研究其生物学特性;通过与商业化菌株LC-01对比,对PC-01制备活菌型乳饮料的能力及产品的贮藏稳定性进行评价。结果:经鉴定,菌株PC-01为类干酪乳酪杆菌(副干酪乳杆菌),该菌株pH值耐受范围3~9,生长温度范围15~50℃,最适生长温度32.5℃,对半乳糖、葡萄糖及酵母浸粉的利用能力强。菌株PC-01可在37℃下单菌株制备活菌型乳酸菌饮料,且产品在4℃和10℃下贮藏能保持较高的活菌数和良好的稳定性,与商业菌株LC-01发酵产品无显著差异。结论:菌株PC-01是一株典型的类干酪乳酪杆菌(副干酪乳杆菌),可用于活菌型乳酸菌饮料的生产,对其基本生物学特性的研究可为其工业应用奠定基础。

Objective:In the present study,multi-phase identification and biological characteristics of the strain PC-01 was performed,the product characteristics of active lactic acid bacteria beverage which was fermented by strain PC-01 was evaluated.Methods:Microbial identification technologies including morphology,physiological and whole genome sequencing were used to identify strain PC-01 at specie level.The biological characteristics of the strain PC-01 were studied through their growth ability at different temperatures and pH,and their ability to utilize different carbon sources and nitrogen sources.By comparing with the commercial strain LC-01,the ability of strain PC-01 to ferment milk for preparing live-bacteria beverages and the storage stability of the products were evaluated.Result:The strain PC-01 was identified as Lacticaseibacillus paracasei(Lactobacillus paracasei),the pH tolerance range of strain PC-01 is 3-9,the growth temperature range of PC-01 is 15-50℃,and the optimal growth temperature of PC-01 is 32.5℃.The ability of strain PC-01 to utilize galactose,glucose and yeast extract is good.The live-bacteria milk beverages can be manufactured by strain PC-01 at 37℃,the final product with a high number of viable cells and good stability when stored at 4℃and 10℃.There are no significant differences between the products which were fermented by strain PC-01 or commercial strain LC-01.Conclusion:The strain PC-01 is a typical Lacticaseibacillus paracasei(Lactobacillus paracasei),which can be used to ferment milk for preparing live-bacteria beverages.Through the exploration of its basic biological characteristics,laying the foundation for its future research and application.