【摘要】 唾液乳杆菌对人体健康有重要意义,作为一株可食用益生菌有着极大的应用潜力,但较低的电转化效率限制了唾液乳杆菌的遗传操作。本研究从细菌培养状态、甘氨酸浓度、蔗糖浓度、电压和复苏时间等因素着手对唾液乳杆菌(Lactobacillus salivarius AR612)的电转化条件进行优化。结果表明,唾液乳杆菌AR612的最佳电转化参数为:OD600为0.1,甘氨酸浓度10 g/L,蔗糖浓度0.3mol/L,电压7.5 kV/cm,复苏时间3 h。在优化条件下,电转化效率最高可达1.16 × 108 CFU/μg DNA。与优化前(2.33 × 105 CFU/μg DNA)相比,转化效率提升了3个数量级。本文通过电转化参数的优化,成功地提高了唾液乳杆菌菌株AR612的转化效率,为进一步解析唾液乳杆菌功能基因及益生机制奠定了基础。更多还原

【Abstract】 Lactobacillus salivarius has a vital influence on human health and has great probiotic potential for industrial application.However,its low transfection efficiency limits the ability for additional genetic manipulation.In this study,a single factor experiment was utilized to optimize electroporation parameters of L.salivarius AR612,including cell growth status,glycine concentration,sucrose concentration,voltage and resurgent time.The optimal electroporation parameters were as follows:OD₆₀₀ 0.1,glycine concentration 10 g/L,sucrose concentration 0.3 mol/L,voltage 7.5 kV/cm and resurgent time 3 h.Under the optimized conditions,the highest transformation efficiency was up to 1.16 × 10⁸ CFU/μg DNA.The efficiency enhanced by three orders of magnitude when compared with the value before optimization（2.33 ×10⁵ CFU/μg DNA）.As a result,the transformation efficiency was successfully improved by optimizing the electrotransformation conditions for strain AR612.This study laid the foundation for further exploration of probiotic mechanism through analysis of the functional genes of L.salivarius.更多还原