嗜热链球菌S-3高密度生长培养基优化  

Optimization of High-density Fermentation Medium for Streptococcus Thermophilus S-3

作　　者：刘从莹 艾连中[1] 熊智强[1] 闫露露 李飘然 宋馨[1] LIU Congying;AI Lianzhong;XIONG Zhiqiang;YAN Lulu;LI Piaoran;SONG Xin(College of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093

出　　处：《工业微生物》2024年第6期169-176,共8页Industrial Microbiology

基　　金：国家自然科学基金资助项目(No.32101928);国家自然科学基金杰出青年基金资助项目(No.32025029);中国食品科学技术学会食品科技基金-养乐多肠道健康与益生菌专项青年科研基金资助项目(No.2023-Y03)。

摘　　要：嗜热链球菌一般可用于发酵食品的生产环节。基于此,文章对传统的LM17培养基进行了优化,通过改良碳源、氮源以及无机盐种类、含量等,实现了嗜热链球菌S-3的高密度生长,满足了工业发酵要求。研究通过比较乳糖、半乳糖、葡萄糖、蔗糖、果糖等碳源,确定最优碳源为乳糖;酵母浸粉为固定氮源,将其与牛肉浸粉、大豆蛋白胨和酵母浸粉分别复配,发现酵母浸粉与牛肉浸粉复配是最佳搭配。文章构建了嗜热链球菌S-3全基因尺度代谢网络模型,以预测尿素替代β-磷酸甘油二钠的效果。验证结果显示,尿素能显著提高嗜热链球菌S-3的生长速率。最终改良培养基中的物质包括:10 g/L乳糖、10 g/L酵母浸粉、15 g/L牛肉浸粉、3 g/L食品级尿素、1.1 g/L Mg SO_(4)·7H_(2)O。为研究最优配制比例,对各因素进行了单因素优化及正交实验。实验结果表明,当乳糖15 g/L、牛肉浸粉15 g/L、酵母浸粉11 g/L、尿素4 g/L、MgSO4·7H2O 1 g/L时,发酵效果最优,放大培养后的OD600已由优化前的4提高至5。Streptococcus thermophilus can generally be used in the production of fermented foods.Based on this,the paper optimized the traditional LM17 medium by improving the types and contents of carbon sources,nitrogen sources,and inorganic salts,and achieved high-density growth of Streptococcus thermophilus S-3 to meet industrial fermentation requirements.By comparing carbon sources such as lactose,galactose,glucose,sucrose,and fructose,the optimal carbon source was determined to be lactose;Yeast extract powder was used as a fixed nitrogen source and was compounded with beef extract powder,soy peptone,and yeast extract powder.It was found that the combination of yeast extract powder and beef extract powder was the optimal choice.This study constructed a genome-wide metabolic network model of Streptococcus thermophilus S-3 to predict the effect of urea replacing β-glycerol-3-phosphate disodium.The validation results showed that urea could significantly improve the growth rate of Streptococcus thermophilus S-3.The substances in the final improved culture medium included 10 g/L lactose,10 g/L yeast extract,15 g/L beef extract,3 g/L food grade urea,and 1.1 g/L MgSO_(4)·7H_(2)O.To study the optimal formulation ratio,single factor optimization and orthogonal experiments were conducted on each factor.The experimental results showed that the fermentation effect was optimal when lactose was 15 g/L;beef extract was 15 g/L;yeast extract was 11 g/L;urea was 4 g/L,and MgSO_(4)·7H_(2)O was 1 g/L.The OD600 after amplification cultivation increased from 4 to 5.

关 键 词：嗜热链球菌 培养基优化 高密度发酵 

分 类 号：TS201.3[轻工技术与工程—食品科学]