模拟胃肠环境对3株光合细菌存活率影响的实验研究

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(P0.01);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(P0.01),处理90、180 min对菌株Ga存活率有显著影响(P0.05),处理180 min对菌株2C存活率无显著影响(P0.05);pH4.0时模拟胃液处理180 min对3株PSB存活率无显著影响(P0.05)。模拟小肠液处理240 min对3株PSB菌株活菌数无显著影响(P0.05)。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。

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

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.