乳双歧杆菌Probio-M8氧气耐受性驯化研究

Studies on Oxygen-tolerant Domestication of Bifidobacterium animalis subsp.lactis Probio-M8

氧气对双歧杆菌具有毒性作用,导致菌体活力受损,限制其生产及应用。为提高双歧杆菌对氧气的耐受性,采用改变培养基中氧分压的方法对乳双歧杆菌Probio-M8进行氧气耐受性驯化。通过测定生理特性、氧气耐受性相关NADH氧化酶活性及细胞膜流动性变化,评价氧气对乳双歧杆菌Probio-M8的影响。结果表明:氧气耐受性驯化后1000代菌株与原始菌株相比在有氧及厌氧环境中,pH值显著下降0.23和0.27(P<0.05),产酸能力明显提升;RBGR值、NADH氧化酶活性显著上升0.47和31.14 U(P<0.05),氧气耐受性明显增强;不饱和脂肪酸含量显著上升17.26%(P<0.05),细胞膜流动性增强。氧气耐受性驯化后乳双歧杆菌Probio-M8的氧气耐受性明显增强,为其在食品中应用及开发提供借鉴。

Oxygen is toxic effect on Bifidobacteria.The viability of the cells is greatly affected,therefore,hindering its production and application.In order to improve the oxygen tolerance of Bfidobacteria,this experiment used the method of changing the partial pressure of oxygen in liquid medium to carry out the oxygen-tolerant domestication of Bifidobacterium animalis subsp.lactis Probio-M8.The effect of oxygen on Bifidobacterium animalis subsp.lactis Probio-M8 was evaluated by measuring physiological characteristics,oxygen tolerance,and cell membrane fluidity.After oxygen-tolerant if domestication 1000 generations of growth when the aerobic and anaerobic environment,the pH of culture medium decreased significantly by 0.23 and 0.27(P<0.05),and the acid production capacity increased significantly.The relative bacterial growth ratio(RBGR)and NADH oxidase activity increased significantly by 0.47 and 31.14 U(P<0.05),and the oxygen tolerance was significantly enhanced.The unsaturated fatty acid content increased significantly by 17.26%(P<0.05),and the cell membrane fluidity was enhanced.After oxygen-tolerant domestication,the oxygen tolerance of Bifidobacterium animalis subsp.lactis Probio-M8 was significantly enhanced,which provided ideas for its application and development in food.