不同乳酸菌响应乙醇胁迫生物膜形成的差异性分析

Differential analysis of biofilm formation of different lactic acid bacteria in response to ethanol stress

中文关键词:  乳酸菌  乙醇胁迫  生长特性  生物膜  金属离子

英文关键词:lactic acid bacteria  ethanol stress  growth characteristics  biofilm  metal ions

中文摘要:

      目的 筛选乙醇胁迫抗性强的乳酸菌株, 研究不同乙醇浓度下, 环境扰动时对菌株生物膜的影响。方法 观察了不同乳酸菌在乙醇胁迫下生长繁殖, 生物膜形成及形态和疏水性的差异, 揭示不同金属离子和D-半乳糖对其生长和生物膜造成的影响。结果 副干酪乳杆菌(Lacticaseibacillus paracasei)在10%乙醇浓度胁迫下发酵48 h后, 其生物量和生物膜量分别为1.16和0.12。发酵24 h后疏水性可达42.80%, 显著高于植物乳植杆菌(Lactiplantibacillus plantarum)、干酪乳杆菌(Lacticaseibacillus casei)、发酵粘液乳杆菌(Limosilactobacillus fermentun), 表现为较好的乙醇胁迫抗性。扫描电镜发现, 乳酸菌生物膜厚度与乙醇浓度呈负相关。D-半乳糖加入会显著抑制乳酸菌生物膜形成, 同时金属离子(Ca2+、Na+)也具有相似作用。结论 乳酸菌通过形成生物膜抵抗乙醇胁迫, 其乙醇胁迫抗性与生物膜形成量有关。此外, D-半乳糖和金属离子会影响乳酸菌生长特性和生物膜的形成。揭示了乳酸菌抗乙醇胁迫与生物膜形成的关系, 为开发高乙醇食品发酵环境的乳酸菌生物制剂提供理论参考和数据基础。

英文摘要:

      Objective To screen lactic acid bacteria strains with strong ethanol stress resistance and investigate the effects of their biofilms under different ethanol concentrations and environmental disturbances. Methods The growth, biofilm formation, morphological changes and hydrophobicity of various lactic acid bacteria under ethanol stress were examined. The effects of different metal ions and D-galactose on the growth and biofilm formation of lactic acid bacteria were also explored. Results After 48 h of fermentation under 10% ethanol stress, the biomass and biofilm amount of Lacticaseibacillus paracasei were 1.16 and 0.12, respectively. After 24 h of fermentation, its hydrophobicity reached 42.80%, significantly higher than that of Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Limosilactobacillus fermentum, indicating better ethanol stress resistance. Scanning electron microscopy showed that the thickness of the biofilm decreased significantly with increasing ethanol concentration. The addition of D-galactose and metal ions (Ca2+, Na?) significantly inhibited biofilm formation. Conclusion Lactic acid bacteria resist ethanol stress through biofilm formation, with ethanol stress resistance correlating closely to biofilm production. D-galactose and metal ions affect the growth and biofilm formation of lactic acid bacteria. This study reveals the relationship between ethanol stress resistance and biofilm formation in lactic acid bacteria, provides a theoretical basis and data support for developing lactic acid bacteria biopreparations suitable for high-ethanol food fermentation environments.