传统发酵豆酱中嗜盐四联球菌的分离鉴定及增鲜菌株筛选

Isolation and Identification of Tetragenococcus halophilus Strains from Traditional Fermented Soybean Paste and Screening for Their Umami-Enhancing Activity

为了获得高产鲜味肽嗜盐四联球菌(Tetragenococcus halophilus)优良菌株,从辽宁省7个不同地区的96份自然发酵豆酱样品中分离出嗜盐四联球菌疑似菌株83株,通过提取各菌株DNA、16S rDNA序列测定和同源性对比分析,其中47株菌为嗜盐四联球菌,分别测定47株菌的产多肽能力、产γ-谷氨酰转肽酶能力、产蛋白酶能力、电子舌风味值分析等指标,结合因子分析以及因子得分综合评价,筛选得到LY9-1产鲜味肽潜力最佳,通过电子舌结果也证明,LY9-1发酵液鲜味值最高,为15.05±0.02,产蛋白酶活力高达(85.45±0.03)U/mL,产γ-谷氨酰转肽酶能力(44.23±0.03)U/mL,产多肽(17.55±0.13)mg/mL,推测该菌株具有较强的增鲜潜力,可为进一步研究增鲜机理以及在发酵食品增鲜中的产业化应用提供理论支持。

This study was implemented in order to obtain Tetraplococcus halophilus with the ability to produce umami peptides.A total of 83 strains suspected of being T.halophilus were isolated from 96 naturally fermented soybean paste samples from seven different areas of Liaoning province.Through DNA extraction,16S rDNA sequencing and comparative homology analysis,47 of these strains were identified as T.halophilus and were screened for their ability to produce polypeptide,γ-glutamyl transpeptidase and protease and their electronic tongue flavor values.Moreover,factor analysis and factor score comprehensive evaluation were carried out,revealing that T.halophilus LY9-1 had the greatest potential to produce umami peptides.The results of electronic tongue also proved that the fermentation broth of T.halophilus LY9-1 had the highest umami value of 15.05±0.02,as well as protease activity of(85.45±0.03)U/mL,γ-glutamyl transpeptidase activity of(44.23±0.03)U/mL,and polypeptide production of(17.55±0.13)mg/mL.It is speculated that the strain has a strong umami-enhancing potential.The findings reported here can motivate further research on the umami-enhancing mechanism and encourage the industrial application of T.halophilus LY9-1 to enhance the umami of fermented foods.