Janthinobacterium CG23_2: Comparative Genome Analysis Reveals Enhanced Environmental Sensing and Transcriptional Regulation for Adaptation to Life in an Antarctic Supraglacial Stream
Janthinobacterium CG23_2: Comparative Genome Analysis Reveals Enhanced Environmental Sensing and Transcriptional Regulation for Adaptation to Life in an Antarctic Supraglacial Stream
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DOI：
10.3390/microorganisms7100454
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发表时间：
2019-10-01
期刊：
影响因子：
4.5
通讯作者：
Foreman, Christine M.
中科院分区：
文献类型：
--
作者：
Dieser, Markus;Smith, Heidi J.;Foreman, Christine M.
由于在南极环境中发现的许多细菌既不是真正的嗜冷菌，也不是地方性物种，尽管环境极端，它们的繁殖导致了基因组的适应。简氏杆菌属(Jansinobterium sp.)CG23_2是从南极科顿冰川流中分离到的一株细菌。为了解简氏杆菌是如何被分离出来的。CG23_2已经适应了它的环境，我们研究了它的基因组特征，并与已发表的35个日本细菌种的基因组进行了比较。虽然我们假设基因组的收缩和专业化以缩小生态位将在能量上有利于栖息在短暂的南极溪流中，但简氏杆菌的基因组。CG23_2的平均大小为1.7+/-0.6Mb，预测的编码序列比其他金杆菌多1411+/-499个。推定的水平基因转移事件对简氏杆菌基因组大小的扩大贡献了0.92Mb。CG23_2.种属特有的副基因组中高拷贝数基因CG23_2与环境感知、运动、反应和转录调节、胁迫响应和移动元件相关，这些功能元件也显示出对冷的分子适应。我们的数据表明，基因组的可塑性和丰富的互补基因对胞外环境的感知和响应支持了简氏杆菌的适应。CG23_2对这一极端环境的影响。
As many bacteria detected in Antarctic environments are neither true psychrophiles nor endemic species, their proliferation in spite of environmental extremes gives rise to genome adaptations. Janthinobacterium sp. CG23_2 is a bacterial isolate from the Cotton Glacier stream, Antarctica. To understand how Janthinobacterium sp. CG23_2 has adapted to its environment, we investigated its genomic traits in comparison to genomes of 35 published Janthinobacterium species. While we hypothesized that genome shrinkage and specialization to narrow ecological niches would be energetically favorable for dwelling in an ephemeral Antarctic stream, the genome of Janthinobacterium sp. CG23_2 was on average 1.7 +/- 0.6 Mb larger and predicted 1411 +/- 499 more coding sequences compared to the other Janthinobacterium spp. Putatively identified horizontal gene transfer events contributed 0.92 Mb to the genome size expansion of Janthinobacterium sp. CG23_2. Genes with high copy numbers in the species-specific accessory genome of Janthinobacterium sp. CG23_2 were associated with environmental sensing, locomotion, response and transcriptional regulation, stress response, and mobile elements-functional categories which also showed molecular adaptation to cold. Our data suggest that genome plasticity and the abundant complementary genes for sensing and responding to the extracellular environment supported the adaptation of Janthinobacterium sp. CG23_2 to this extreme environment.