Shivaji S, Chaturvedi P, Suresh K, Reddy G S N, Dutt C B S, Wainwright M, Narlikar J V, Bhargava P M
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Indian Space Research Organization, Antariksha Bhavan, New BEL Road, Bangalore 500 094, India.
Int J Syst Evol Microbiol. 2006 Jul;56(Pt 7):1465-1473. doi: 10.1099/ijs.0.64029-0.
Four novel bacterial strains were isolated from cryogenic tubes used to collect air samples at altitudes of 24, 28 and 41 km. The four strains, 24K(T), 28K(T), 41KF2a(T) and 41KF2b(T), were identified as members of the genus Bacillus. Phylogenetic analysis based on 16S rRNA gene sequences indicated that three of the strains, 24K(T), 28K(T) and 41KF2a(T), are very similar to one another (>98 % sequence similarity) and show a similarity of 98-99 % with Bacillus licheniformis and 98 % with Bacillus sonorensis. DNA-DNA hybridization studies showed that strains 24K(T), 28K(T) and 41KF2a(T) exhibit <70 % similarity with each other and with B. licheniformis and B. sonorensis. Differences in phenotypic and chemotaxonomic characteristics between the novel strains and B. licheniformis and B. sonorensis further confirmed that these three isolates are representatives of three separate novel species. Strain 41KF2b(T) showed 100 % 16S rRNA gene sequence similarity to Bacillus pumilus, but differed from its nearest phylogenetic neighbour in a number of phenotypic and chemotaxonomic characteristics and showed only 55 % DNA-DNA relatedness. Therefore, the four isolates represent four novel species for which the names Bacillus aerius sp. nov. (type strain, 24K(T)=MTCC 7303(T)=JCM 13348(T)), Bacillus aerophilus sp. nov. (type strain, 28K(T)=MTCC 7304(T)=JCM 13347(T)), Bacillus stratosphericus sp. nov. (type strain, 41KF2a(T)=MTCC 7305(T)=JCM 13349(T)) and Bacillus altitudinis sp. nov. (type strain, 41KF2b(T)=MTCC 7306(T)=JCM 13350(T)) are proposed.
从用于在24、28和41千米高度采集空气样本的低温管中分离出4株新型细菌菌株。这4株菌株，即24K(T)、28K(T)、41KF2a(T)和41KF2b(T)，被鉴定为芽孢杆菌属成员。基于16S rRNA基因序列的系统发育分析表明，其中3株菌株，即24K(T)、28K(T)和41KF2a(T)，彼此非常相似（序列相似性>98%），与地衣芽孢杆菌的相似性为98 - 99%，与索诺拉芽孢杆菌的相似性为98%。DNA - DNA杂交研究表明，24K(T)、28K(T)和41KF2a(T)菌株相互之间以及与地衣芽孢杆菌和索诺拉芽孢杆菌的相似性均<70%。新型菌株与地衣芽孢杆菌和索诺拉芽孢杆菌在表型和化学分类特征上的差异进一步证实，这3株分离株是3个独立新物种的代表。菌株41KF2b(T)与短小芽孢杆菌的16S rRNA基因序列相似性为100%，但其在一些表型和化学分类特征上与其最接近的系统发育邻居不同，且DNA - DNA相关性仅为55%。因此，这4株分离株代表4个新物种，分别命名为高空芽孢杆菌（Bacillus aerius sp. nov.）（模式菌株，24K(T)=MTCC 7303(T)=JCM 13348(T)）、嗜气芽孢杆菌（Bacillus aerophilus sp. nov.）（模式菌株，28K(T)=MTCC 7304(T)=JCM 13347(T)）、平流层芽孢杆菌（Bacillus stratosphericus sp. nov.）（模式菌株，41KF2a(T)=MTCC 7
