耐盐乳酸菌的益生特性及其在酱油发酵中的应用

Probiotic Properties of Salt-Tolerant Lactic Acid Bacteria and Their Applications in Soy Sauce Fermentation

摘要:

食品来源的耐盐乳酸菌（LAB）具有安全性和一定的抗逆特性，研究它们的益生特性和发酵特性对寻找可用于食品发酵的功能菌株具有重要意义。作者考察了5株来源于酱油发酵酱醪的乳酸菌的抑菌、抗氧化能力和对胃酸、胆盐与溶菌酶的耐受能力，以及对冻干和高温条件的抗性，并评估了乳酸菌协同高盐稀态酱油发酵的能力。结果表明，5株乳酸菌可在低盐质量浓度(50 g/L)下生长，且对中高盐质量浓度(100 g/L和150 g/L)有良好的耐受能力。这些耐盐乳酸菌皆具有低疏水性，可抑制大肠杆菌和鼠伤寒沙门氏菌等致病菌，并有良好的抗氧化能力。其中Pediococcus acidilactici ZQ1与Pediococcus acidilactici WT1对胃酸、胆盐和溶菌酶的耐受能力高于Pediococcus pentosaceus WT6、Weissella paramesenteroides JL-5、Weissella paramesenteroides LCW-28和对照菌Lactiplantibacillus plantarum JP31。此外，P. acidilactici WT1经冷冻干燥处理后的存活率最高(85%)，且该菌株在60 ℃下的存活率比L. plantarum JP31高2个数量级。利用P. acidilactici WT1协同高盐稀态酱油发酵，可使酱油中氨基酸态氮和有机酸质量浓度分别提高11.03%和34.42%。该研究初步证实了食品来源的耐盐乳酸菌的益生特性和用于酱油发酵的潜力。

Abstract:

Salt-tolerant lactic acid bacteria (LAB) derived from food resources are generally safe and tolerant to stress. Studying their probiotic and fermentation characteristics is of great significance for finding novel functional strains that can be used for food fermentation. Probiotic characteristics including antimicrobial activity, antioxidant capacity and tolerance to gastric acid, bile salts and lysozyme of 5 strains of salt-tolerant LAB from soy sauce moromi were investigated in this study. Their resistance to freeze-drying and high temperature conditions were also investigated and the synergistic ability of the 5 strains in high-salt liquid-state soy sauce fermentation was evaluated. The results showed that 5 strains of LAB could grow under low salinity (50 g/L) and had good tolerance to medium and high salinity (100 g/L and 150 g/L). These salt-tolerant LAB strains showed low hydrophobicity and could inhibit pathogens such as Escherichia coli and Salmonella typhimurium. These strains have good antioxidant capacity. Among them, the tolerance of Pediococcus acidilactici ZQ1 and Pediococcus acidilactici WT1 to gastric acid, bile salts and lysozyme are higher than that of Pediococcus pentosaceus WT6, Weissella paramesenteroides JL-5, Weissella paramesenteroides LCW-28, as well as the control strain Lactiplantibacillus plantarum JP31. In addition, the survival rate of P. acidilactici WT1 after freeze-drying treatment was the highest (85%) and the survival rate of this strain at 60 ℃ was 2 orders of magnitude higher than that of L. plantarum JP31. P. acidilactici WT1 increased the mass concentrations of amino acid nitrogen and organic acids in soy sauce by 11.03% and 34.42%, respectively, through synergistic fermentation. The results of this study preliminarily confirm the probiotic properties of food-derived salt-tolerant LAB and their potential applications in soy sauce fermentation.