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投稿时间：2023-05-01
投稿时间：2023-05-01
中文摘要: 为获取谷胱甘肽过氧化物酶（glutathione peroxidase，GPx）基因重组乳酸菌NZ9000/pNZ8148-GPx（简称NG1）的最优生长条件和在模拟胃肠道环境下的抗逆性情况，采用单因素试验和响应面分析法优化NG1 的生长条件，同时对该重组菌的体外抗H2O2、抗胆汁酸盐和抗酸胁迫能力进行研究。结果表明，NG1 的最优生长条件为培养温度36 ℃、初始pH7.6、Na2SeO3 浓度59 μg/mL；NG1 对各胁迫因素的最高耐受值分别为过氧化氢（H2O2）1.5 mmol/L、胆汁酸盐0.20%、酸度pH6.0；耐受能力排序为优化培养NG1>常规培养NG1>常规培养NG0（NZ9000/pNZ8148），说明GPx 基因的导入对乳酸菌的抗H2O2 和胆汁酸盐胁迫功能有增强作用，且在最优培养时得到强化，但对酸度耐受性无明显增强作用。
Abstract:To obtain the optimal growth conditions for the glutathione peroxidase（GPx）recombinant lactic acid bacteria NZ9000/pNZ8148-GPx（NG1）and assessitsstressresistance under simulated gastrointestinal conditions，single-factor experiments and response surface analysis were conducted for optimizationof growth conditions for NG1.Additionally，the in vitro resistance of the recombinant strain to H2O2，bile salts，and acid stress was studied.The results showed that the optimal growth conditions for NG1 were as follows：cultivation temperature of 36 ℃，initial pH7.6，and Na2SeO3 concentration of 59 μg/mL.The highest tolerance values of NG1 to various stress factors were 1.5 mmol/L for H2O2，0.20% for bile acid salts，and pH6.0 for acidity.The tolerance ranking was as follows：NG1 under optimal cultivation>NG1 under conventional cultivation>NG0（NZ9000/pNZ8148）under conventional cultivation，indicating that the introduction of the GPx enhanced the stress resistance of the lactic acid bacteria to H2O2 and bile acid salts，especially under optimal cultivation conditions.However，there was no significant enhancement of acid tolerance.
keywords: lactic acid bacteria Lactococcus lactis glutathione peroxidase（GPx） growth optimization tolerance test stress resistancefunction
文章编号：202319024 中图分类号： 文献标志码：
基金项目:国家自然科学基金面上项目（31972050）
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