PDF(Pubmed)
Abstract：
Komagataeibacter is the dominant taxon and cellulose-producing bacteria in the Kombucha Microbial Community (KMC). This is the first study to isolate the K. oboediens genome from a reactivated space-exposed KMC sample and comprehensively characterize it. The space-exposed genome was compared with the Earth-based reference genome to understand the genome stability of K. oboediens under extraterrestrial conditions during a long time. Our results suggest that the genomes of K. oboediens IMBG180 (ground sample) and K. oboediens IMBG185 (space-exposed) are remarkably similar in topology, genomic islands, transposases, prion-like proteins, and number of plasmids and CRISPR-Cas cassettes. Nonetheless, there was a difference in the length of plasmids and the location of cas genes. A small difference was observed in the number of protein coding genes. Despite these differences, they do not affect any genetic metabolic profile of the cellulose synthesis, nitrogen-fixation, hopanoid lipids biosynthesis, and stress-related pathways. Minor changes are only observed in central carbohydrate and energy metabolism pathways gene numbers or sequence completeness. Altogether, these findings suggest that K. oboediens maintains its genome stability and functionality in KMC exposed to the space environment most probably due to the protective role of the KMC biofilm. Furthermore, due to its unaffected metabolic pathways, this bacterial species may also retain some promising potential for space applications.
摘要：
Komagataeibacter是红茶菌微生物群落（KMC）中的主要分类单元和产生纤维素的细菌。这是第一项从重新激活的空间暴露的KMC样品中分离出双歧杆菌基因组并对其进行全面表征的研究。将太空暴露的基因组与基于地球的参考基因组进行了比较，以了解长期在外星条件下的双臂K.obediens的基因组稳定性。我们的结果表明，K.obediensIMBG180（地面样本）和K.obediensIMBG185（空间暴露）的基因组在拓扑结构上非常相似，基因组岛，转座酶,朊病毒样蛋白，以及质粒和CRISPR-Cas盒的数量。尽管如此，质粒的长度和cas基因的位置存在差异。在蛋白质编码基因的数量上观察到微小的差异。尽管存在这些差异,它们不会影响纤维素合成的任何遗传代谢谱，固氮,hopanoid脂质生物合成，和压力相关的途径。仅在中央碳水化合物和能量代谢途径的基因数量或序列完整性中观察到微小的变化。总之,这些发现表明，在暴露于太空环境的KMC中，K.obediens保持其基因组稳定性和功能，很可能是由于KMC生物膜的保护作用。此外，由于其不受影响的代谢途径，这种细菌也可能保留一些有希望的空间应用潜力。
