模拟胃肠环境对3株光合细菌存活率影响的实验研究

Survival assessment of three strains of Photosynthetic bacteria in simulated gastrointestinal conditions in vitro

目的模拟胃肠环境对3株光合细菌(Photosynthetic bacteria,PSB)存活率影响进行体外实验研究。方法测定3株PSB分别在pH2.0、3.0和4.0的模拟胃液及含有或不含有0.45%牛胆盐(pH8.0)的模拟小肠液中不同时间的存活率。结果pH2.0时模拟胃液处理不同时间对3株PSB存活率有显著影响(P<0.01);pH3.0时,模拟胃液处理60、90和180 min对菌株rub存活率有显著影响(P<0.01),处理90、180 min对菌株Ga存活率有显著影响(P<0.05),处理180 min对菌株2C存活率无显著影响(P>0.05);pH4.0时模拟胃液处理180 min对3株PSB存活率无显著影响(P>0.05)。模拟小肠液处理240 min对3株PSB菌株活菌数无显著影响(P>0.05)。结论模拟胃液对3株PSB存活率影响具有菌株特异性和pH依赖性,而模拟小肠液对3株PSB存活率无显著影响。

Objective To evaluate survival rate of 3 strains of Phtotosynthetic bacteria（PSB） in simulated gastrointestinal conditions in vitro.Method The survival rate of 3 PSB strains were determined at 37 ℃ by exposing washed cell suspensions to simulate gastric juices at pH 2.0,3.0 and 4.0,as well as simulated small intestinal juices（pH 8.0） with or without 0.45% bile salts,respectively.Result The simulated gastric juice had significant effect on the transit survival of 3 PSB strains at pH 2.0 at various intervals（P〈0.01）;It had significant effect on the transit survival of rub strain treated for 60 min,90 min and 180 min at pH 3.0（P〈0.01）, while no significant effect on that of Ga strain treated for 90 min and 180 min（P〈0.05） as well as 2C strain treated for 180 min（P〉0.05） at pH 3.0;The simulated gastric juice had no significant effect on the transit survival of 3 PSB at pH 4.0 under various intervals treatment.The simulated small intestinal juices had no significant effect on the transit survival of 3 PSB under 240 min treatment.Conclusion The simulated gastric transit survival of photosynthetic bacteria is stain-specific and pH-dependent while the 3 tested strains survive well during simulated small intestinal transit.