| 摘要: |
| 【目的】筛选具有抑制脂环酸芽孢杆菌活性的乳酸菌，并对其抑菌活性进行研究，为延长果汁的保质期和提高产品的安全性提供理论基础。【方法】用琼脂扩散法，从50株分离自泡菜的乳酸菌中筛选具有抑制脂环酸芽孢杆菌活性的菌株，研究所获菌株发酵上清液（Cell free supernatant，CFS）经不同pH（3，4，5，6，7）、温度（40，60，80，100，121 ℃）和酶（过氧化氢酶、链霉蛋白酶、蛋白酶K、胃蛋白酶、胰蛋白酶）处理后抑菌活性的变化；通过气相色谱 质谱分析乳酸菌代谢物中的组成成分；利用扫描电镜观察CFS处理后脂环酸芽孢杆菌的形态变化；将乳酸菌应用于苹果汁的发酵，并测定发酵过程中乳酸菌和脂环酸芽孢杆菌生长及6种有机酸含量的变化情况。【结果】筛选得到1株具有较好抑菌活性的植物乳杆菌（L10），其代谢物抑菌活性呈pH依赖性，具有温度和过氧化氢酶稳定性，但蛋白酶水解会降低其抑菌活性。植物乳杆菌L10代谢物中的成分主要是有机酸，并且含有环（亮氨酸 脯氨酸）和环（甘氨酸 脯氨酸）两种环二肽。CFS通过对脂环酸芽孢杆菌的细胞壁和细胞膜造成严重损害，导致细胞破裂，达到杀菌的目的。植物乳杆菌L10能够抑制苹果汁中脂环酸芽孢杆菌的生长，并且发酵后主要有机酸的含量发生显著变化（P＜0.05）。【结论】植物乳杆菌L10可以产生有机酸、细菌素等抑菌物质来杀灭脂环酸芽孢杆菌，可以应用于果汁的发酵及生物保存。 |
| 关键词: 乳酸菌 脂环酸芽孢杆菌 植物乳杆菌 抑菌活性 果汁发酵 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（31671866） |
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| Antibacterial activity of a Lactobacillus plantarum strain against Alicyclobacillus acidoterrestris |
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XU Zhijiao,HAN Xiaojiang,SONG Zihan,et al
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| Abstract: |
| 【Objective】The lactic acid bacteria (LAB) with antibacterial activity against Alicyclobacillus acidoterrestris was screened and its antibacterial activity was studied to provide basis for improving the shelf life and safety of juice.【Method】The agar well diffusion method was performed to test 50 strains of LAB isolated from pickles for strains with activity against A. acidoterrestris.The changes of antibacterial activity of the CFS of obtained strain were analyzed after treatments of different pH values (3，4，5，6 and 7),temperatures (40，60，80，100 and 121 ℃) and enzymes (catalase,pronase,proteinase K,pepsin and trypsin).Compounds secreted from LAB were analyzed using gas chromatography mass spectrometry (GC-MS).Scanning electron microscopy was used to observe the effect of CFS on the morphology of A. acidoterrestris.The LAB was used to ferment apple juice and the effect of on growth of A. acidoterrestris and contents of six organic acids in the process of fermentation were measured.【Result】A screened strain of Lactobacillus plantarum (L10) had the highest antibacterial activity.The antibacterial activity of L. plantarum L10 metabolites was pH-dependent and had thermal and catalase treatment stability.The antibacterial effect decreased after proteolytic enzymes treatment.The major components were organic acids in the metabolites of L. plantarum L10. Cyclic dipeptides, cyclo (leu-pro) and cyclo (gly-pro) were also found.L. plantarum L10 CFS could cause severe damage to cell wall and cytoplasmic membrane,leading to cell rupture and sterilization.L. plantarum L10 could inhibit the growth of A. acidoterrestris and contents of organic acids were significantly changed (P＜0.05) during the fermentation of apple juice.【Conclusion】L. plantarum L10 could inhibit A. acidoterrestris by producing organic acids,bacteriocin and other antibacterial substances,and it can be applied to juice fermentation and biological preservation. |
| Key words: lactic acid bacteria Alicyclobacillus acidoterrestris Lactobacillus plantarum antibacterial activity apple juice fermentation |
