摘要
从不同地区的传统发酵食品中筛选出104株菌落形态各异的乳酸菌,通过过氧化氢抗性试验筛选出20株具有抗氧化能力的乳酸菌,并测定其产SOD的能力。结果表明,20株乳酸菌中C8的SOD活性最高,达349.62 U/mg。通过革兰氏染色、过氧化氢酶试验和16S rRNA基因序列分析,构建系统发育树,根据同源性分析确定C8为乳酸乳球菌。为提高菌株产SOD的能力,通过单因素实验探究培养温度、初始接种量、初始pH值和灌装量对乳酸乳球菌产SOD的影响,并通过正交试验进一步优化菌株的发酵条件。最终确定最佳发酵条件为:发酵温度37℃,初始接种量3%,初始pH 7.5,灌装量75mL。在此培养条件下,乳酸乳球菌的SOD活性达93.95 U/mL,与优化前相比提高了2.2倍,为后期乳酸乳球菌在发酵产业的应用奠定基础。
104 Lactic acid bacteria(LAB), with different colony morphology, were selected from traditional fermented food produced in different regions. Through the hydrogen peroxide resistance tests, 20 LAB with antioxidant capacity were screened and the ability to produce superoxide dismutase(SOD) were determined. The results indicated that C8 showed the highest SOD activity among 20 LAB, reaching 349.62 U/mg. Then gram staining, catalase experiments, and 16 S rRNA gene sequence analysis were conducted to the identification of C8. Phylogenetic trees were constructed and C8 was determined as Lactococcus lactic according to the homology analysis. In order to improve the ability of Lactococcus lactic to produce SOD, the effects of fermentation temperature, initial inoculation amount, initial pH value and liquid volume on the activity of SOD were explored through single factor experiments, and the fermentation conditions were further optimized through orthogonal experiments. Finally, the optimal fermentation conditions were determined: fermentation tem perature 37 ℃, initial inoculation volume 3%, initial pH 7.5, liquid volume 75 mL. The activity of SOD reached to93.95 U/mL under the optimized fermentation conditions, which was 2.2 times than before, providing a foundation for the application of Lactococcus lactis in fermentation industry.
作者
张秋月
黎谢飞
曾小群
吴振
蔡振东
郭宇星
潘道东
Zhang Qiuyue;Li Xiefei;Zeng Xiaoqun;Wu Zhen;Cai Zhendong;Guo Yuxing;Pan Daodong(Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province,School of Food and Pharmaceutical Sciences,Ningbo University,Ningbo 315211,Zhejiang;School of Food Science and Pharmaceutical Engineering,Nanjing Normal University,Nanjing 210097)
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2021年第10期143-150,共8页
Journal of Chinese Institute Of Food Science and Technology
基金
江苏省科技计划项目(BE2018397)
江苏省农业科技自主创新资金(CX(18)3036)
国家自然科学基金项目(31972048)。
关键词
超氧化物歧化酶
乳酸菌
筛选
发酵条件
优化
superoxide dismutase(SOD)
lactic acid bacteria(LAB)
screening
fermentation conditions
optimization
