空间条件对乳酸菌遗传学及生物学特性的影响

THE EFFECTS OF SPACE AERONAUTICAL CONDITION ON THE GENETIC AND BIOLOGICAL CHARACTERISTICS OF LACTOBACILLI

目的 :了解空间条件对微生物的影响。方法 :L G- 1菌株经“92 10 6”科学返回式卫星搭载 7天 ,返回地面后 ,检测其变化。结果 :搭载返回的 L G- 1菌株死亡数高于对照菌 10 0倍以上 ,但存活的菌株 ,有一个明显延长的生存期。筛选出 2株乳糖、半乳糖发酵缺陷株。 32 %的菌株失去了一个分子量为 3.0道尔顿大小的质粒 ,但未发现它与任何表型有关。结论

Objective:This paper presents the effects of space aeronautical condition on the Lactobacillus spp.LG 1 in 7 day recoverable satellite.Methods:Comparing the difference between the test strains and the control by quantity of the microrganisms,biochemical reactions,drug resistance,frequency of isolation of plasmid DNA,we found that the death rates of test strains were above 100 times higher than those of control,but the living period of those survival cells was much longer.Results:Two of the test strains were found to have lost the lactose and galatose metabolizing abilities.32% of them had lost one of plasmids with a molecular wt about 3 0 megadaltons,which was not found to have any gene endoding its well known drug resistance,carbohydrate metabolism,characteristic proteinase or particular bacteriocin.Conclusion:The study on the effects of space aeronautical condition is undoubtedly an important method for screening industrial strains of microoganisms and for analyzing the normal flora of space areo nautical persons.