| 摘要: |
| 深海微生物由于长期生活在高压、低温、黑暗、寡营养的极端环境中, 必然会发展出与之相应的分子基础。近年来, 对深海微生物极端环境适应性机理的研究是深海微生物研究的前沿课题。通过对一株耐冷、耐压的深海沉积微杆菌Microbacterium sediminis YLB-01进行ARTP诱变, 成功获得了对低温和高压敏感的突变子9-3E5, 突变子9-3E5与野生型菌株的基因组比较分析结果表明, SNP和InDel在突变子9-3E5全基因组上分布均匀, 838个SNP位点位于编码区且为非同义突变, 占总SNP数量的77.45%；27个InDel中11个位于编码区且发生了移码突变；突变子9-3E5共有11条SV序列, 长度为300～400 bp的序列占比为81.82%。以OR值＞2、p<0.05 为标准对突变基因进行富集, 共富集到3个相关的功能集。在与细胞分裂相关的蛋白中发现了11个SNP突变位点, 主要涉及细胞分裂蛋白FtsI、FtsW、FtsX和细胞分裂起始蛋白；在与DNA修复、合成相关的6个基因中发现了10个SNP突变位点；在与胞内运输和能量合成调控相关的2个基因中发现了3个SNP突变位点。我们推测细胞分裂、DNA损伤修复及合成、胞内运输对能量合成的影响这3类功能基因发生改变可能是突变子9-3E5相对于野生株YLB-01低温、高压耐受性改变的原因, M. sediminis YLB-01通过调节这些胞内的生理生化过程来应对外界低温和高压环境。 |
| 关键词: 海洋生物学 ARTP诱变 适应性机制 低温 高压 |
| DOI：10.3969/J.ISSN.2095-4972.2021.03.009 |
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| 基金项目:国家重点基础研究发展计划资助项目(2015CB755901)；自然资源部第三海洋研究基本科研业务费专项资金资助项目(2017035) |
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| ARTP mutagenesis analysis of the pressure and cold tolerance mechanism of deep sea bacterium Microbacterium sediminis YLB-01 |
| QIU Xu,XU Rufang,WEI Shiping,TANG Xixiang |
| (School of Marine Sciences, China University of Geosciences (Beijing), Beijing 100083, China; Third Institute of Oceanography, MNR, Xiamen 361005, China) |
| Abstract: |
| Because of long adaptation to the extreme environment of high pressure, low temperature, darkness and nutrientpoor waters, deep-sea microorganisms are bound to develop a corresponding molecular basis. In recent years, the mechanism of extreme environmental adaptability of deepsea microorganisms is a frontier topic in the study of deepsea microorganism. With atmospheric and room temperature plasma (ARTP) mutagenesis of a cold and pressure tolerant deep-sea actinomycetesMicrobacterium sediminis YLB-01, the mutant 9-3E5 which was sensitive to low temperature and high pressure was successfully obtained. The genome comparative analysis of the mutant 9-3E5 and the wild-type strain showed that the SNP, accounting for 77.45% of the total, and InDels were evenly distributed on the whole genome of mutant 9-3E5 and 838 SNP sites were located in the coding region and were nonsynonymous mutations. There were 11 InDels of frameshift mutation located in the coding region. The mutant 9-3E5 has 11 SV sequences and length 300-400 bp accounting for 81.82% of the total. According to the standard of OR > 2, p < 0.05, the mutant genes were enriched into 3 functional sets. Eleven SNP mutation sites were found in 4 cell division genes of FtsI, FtwW, FtsX and FtsZ. Ten SNP mutation sites were found in 6 genes related to DNA repair and synthesis. Three SNP mutation sites were found in 2 genes related to intracellular transport and energy synthesis regulation. We speculate that the changes of the tolerance of mutant 9-3E5 to low temperature and high pressure compared with wild strain YLB-01 may be due to the changes in three functional genes of cell division, repair and synthesis of DNA damage, and intracellular transport regulates energy synthesis. It is suggested that M. sediminis YLB-01 adjust these intracellular physiological and biochemical processes to cope with external low temperature and high pressure environment. |
| Key words: marine biology ARTP mutagenesis adaptive mechanism low temperature high pressure |
