航天器AIT厂房环境中嗜极微生物的筛选与鉴定

Characterizing extremotolerant bacteria in the Spacecraft Assembly,Integration,and Test Center

航天器组装、集成与测试厂房(AIT厂房)是航天器携带微生物的重要环境来源之一.在深空探测过程中,来自航天器AIT厂房环境中的嗜极微生物可能会对地外星球环境造成正向污染.通过低温(4℃)、一定强度的紫外辐射(Ultraviolet,UVC波段)等筛选条件,应用细菌16S rRNA序列分析,对我国某AIT厂房环境中的耐冷微生物和耐辐射微生物进行筛选与分离鉴定.从AIT厂房环境中共筛选出16株嗜极微生物,包括9株耐辐射微生物和7株耐冷微生物.耐辐射微生物分别属于7个属,其中芽孢杆菌属(Bacillus)和微球菌属(Micrococcus)各2株,土地芽孢杆菌属(Terribacillus)、葡萄球菌属(Staphylococcus)、考克氏菌属(Kocuria)、奇球菌属(Deinococcus)和甲基杆菌属(Methylobacterium)各1株.耐冷微生物分别属于6个属,其中马赛菌属(Massilia)2株,芽孢杆菌属(Bacillus)、节杆菌属(Arthrobacter)、不动杆菌属(Acinetobacter)、假单胞菌属(Pseudomonas)和嗜冷杆菌属(Psychrobacter)各1株.本研究表明AIT厂房内存在一定数量的耐冷和耐辐射微生物,其发现对于我国深空探测任务中继续开展行星保护重点微生物的识别,并针对性地开发空间微生物防控技术和制定操作规范均具有重要意义.(图4表5参31)

The Spacecraft Assembly,Integration and Test Center(AITC)is one of the most important environmental sources of spacecraft-borne microorganisms.In the process of deep space exploration,the extremotolerant bacteria from the spacecraft AITC may cause forward biological contamination to extraterrestrial environments.Therefore,this study conducted screenings,isolations,and identifications of extremotolerant bacteria in the AITC environment.Through the screening conditions of low temperature(4℃)and strong radiation(Ultraviolet,UVC),the 16 S rRNA sequence analysis was applied to screen,isolate,and identify the psychrotolerant and UVC-resistant bacteria in the AITC environment.The nine screened UVC-resistant bacteria belonged to seven genera,including Bacillus and Micrococcus(two strains each),Terribacillus,Staphylococcus,Kocuria,Deinococcus,and Methylobacterium(one strain each).After analyzing the 16 S rRNA sequences of the seven psychrotolerant bacteria,a total of six genera were found,namely,Massilia(two strains),Bacillus,Arthrobacter,Acinetobacter,Pseudomonas,and Psychrobacter(one strain each).Thus,a certain number of extremotolerant bacteria(psychrotolerant and UVC-resistant bacteria)were found in the AITC,where their existence is of great significance for the continued identification of key microorganisms,while ensuring planetary protection in China′s deep space exploration missions.In addition,this work can be used to develop space microorganism prevention and control technologies as well as formulating standard operation procedures for space travel.