摘要
乳酸乳球菌作为发酵乳制品生产中应用最为广泛的发酵剂之一,在食品风味调控等研究领域备受关注。本研究从内蒙古锡林郭勒盟、兴安盟和呼伦贝尔市3个地区采集9份发酵乳制品样品,采用纯培养、全基因组测序等方法筛选鉴定82株乳酸乳球菌,在此基础上,通过测定发酵时间、发酵终点(pH=4.6)时发酵乳中的风味物质,筛选出1株具有优良特性的乳酸乳球菌IMAU13888。与其它菌株相比,该菌株发酵时间最短(13.5 h),在发酵终点时,从其发酵乳中共检出69种挥发性化合物,其中关键性化合物有(OAV≥1)5种,包括2-庚酮、乙偶姻、乙醛、乙酸乙酯、3-甲基丁醛等。主成分及聚类分析结果表明,该菌株发酵乳中风味化合物的种类与含量与对照组BL19之间有较高的相似度。此外,全基因组测序及BLAST的比对分析结果也证明:该菌株基因组中富含调控菌株发酵速率、促进代谢产物生成以及催化糖基转移生成糖苷类化合物等功能基因,这些基因对菌株发酵乳风味的形成具有重要作用。
As one of the most widely used starters in fermented dairy production,Lactococcus lactis(Lc.lactis)has attracted significant attention in the research of food flavor regulation.In this study,nine fermented milk samples were collected from three regions:Xilingol League,Xing'an League,and Hulunbuir City in Inner Mongolia.A total of 82 strains of Lc.lactis were isolated and identified using pure culture and whole-genome sequencing methods.Based on this,a superior strain,Lc.lactis IMAU13888,was screened by measuring flavor substances in fermented milk at different fermentation times and the fermentation end point(pH=4.6).Compared with other strains,this strain showed the shortest fermentation time(13.5 h),and 69 volatile compounds were detected in its fermented milk at the end point,including 5 key compounds with odor activity values(OAV≥1),such as 2-heptanone,acetoin,acetaldehyde,ethyl acetate,and 3-methylbutanal.Results of Principal Component Analysis(PCA)and cluster analysis showed that the types and contents of flavor compounds in the fermented milk of this strain had high similarity to those of the control group BL19.Additionally,whole-genome sequencing and BLAST comparison analysis demonstrated that the genome of this strain was rich in functional genes regulating fermentation rate,promoting metabolite production,and catalyzing glycosyl transfer to generate glycosides,which play important roles in forming the flavor of fermented milk by this strain.
作者
徐冉
李红
韩婉蓉
高倩
王越男
丹彤
XU Ran;LI Hong;HAN Wanrong;GAO Qian;WANG Yuenan;DAN Tong(Key Laboratory of Dairy Biotechnology and Engineering of Ministry of Education,Inner Mongolia Agricultural University,Hohhot 010018;Key Laboratory of Dairy Processing of Ministry of Agriculture and Rural Affairs,Hohhot 010018;Key Laboratory of Dairy Biotechnology and Engineering of Inner Mongolia Autonomous Region,Hohhot 010018)
出处
《中国食品学报》
北大核心
2025年第9期315-332,共18页
Journal of Chinese Institute of Food Science and Technology
基金
国家自然科学基金地区科学基金项目(32360563)
内蒙古自治区自然科学基金项目(2024LHMS03035)。
关键词
乳酸乳球菌
固相微萃取-气相色谱-质谱
发酵特性
OAV
全基因组
Lactococcus lactis
solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)
fermentation characteristics
odor activity value(OAV)
whole genome
