山西老陈醋乳酸菌菌群结构及优良菌株的风味代谢特征

Microbial community structure of lactic acid bacteria in Shanxi aged vinegar production and the flavor metabolism characteristics of superior strains

该研究采用Illumina Miseq高通量测序技术和传统可培养技术分析山西老陈醋大曲、酒醪和醋醅中的乳酸菌菌群结构,并通过传统培养分离技术从中分离筛选产酸性能优良的乳酸菌菌株,采用高效液相色谱(HPLC)及顶空固相微萃取气质联用(HS-SPME-GC-MS)技术分析其在不同模拟培养基中的风味代谢特征。结果表明,大曲的主要乳酸菌属为乳杆菌属(Lactobacillus)和片球菌属(Pediococcus),酒精和醋酸发酵阶段主要乳酸菌属为魏斯氏菌属(Weissella)、乳杆菌属和片球菌属。共筛选出10株高产酸[总酸(8.26~24.30 g/L)和不挥发性酸(5.60~15.3 g/L)]的优良乳酸菌,经鉴定,4株为植物乳植杆菌(Lactiplantibacillus plantarum),2株为短乳杆菌(Lactobacillus brevis),2株为戊糖片球菌(Pediococcus pentosaceus),1为株乳酸片球菌(Pediococcus acidilactici)和1株为耐久肠球菌(Enterococcus durable)。10株乳酸菌菌株在MRS液体培养基和模拟醋醅培养基中代谢产生的有机酸总量和乳酸含量均较高;从4种模拟培养基中共检测出100种挥发性风味成分,菌株在大麦豌豆培养基和模拟醋醅培养基(除乳酸片球菌L729)中代谢产生的挥发性风味物质总量较高;其中,植物乳植杆菌L19具有优良风味代谢特性。

The structure of lactic acid bacteria in Daqu,fermented mash and Cupei of Shanxi aged vinegar was analyzed by Illumina Miseq high-throughput sequencing technology and traditional cultivable technology,and the lactic acid bacteria strains with excellent acid production ability were isolated and screened through traditional culture separation technology.The flavor metabolism characteristics in different simulated media were analyzed by HPLC and HS-SPME-GC-MS.The results showed that the main lactic acid bacteria genera in Daqu were Lactobacillus and Pediococcus,and the main lactic acid bacteria genera in the alcohol and acetic acid fermentation stages were Weissella,Lactobacillus and Pediococcus.A total of 10 strains of excellent lactic acid bacteria with high acid production[total acid(8.26-24.30 g/L)and non-volatile acid(5.60-15.3 g/L)]were screened.After identification,4 strains were Lactiplantibacillus plantarum and 2 strains were Lactobacillus brevis,2 strains were Pediococcus pentosaceus,1 strain was Pediococcus acidilactici,and 1 strain was Enterococcus durable.The total organic acids and lactic acid contents of 10 strains of lactic acid bacteria were higher in MRS liquid medium and simulated Cupei medium.A total of 100 volatile flavor components were detected from the 4 simulated media,the total contents of volatile flavor compounds produced by the strains were higher in barley pea medium and simulated Cupei medium(except for P.acidilactici L729).Among them,L.plantarum L19 had excellent flavor metabolism characteristics.