深渊严格嗜压菌Moritella yayanosii DB21MT-5鞭毛系统适应高压环境的机制研究

深渊指水深超过6000米的海沟区域，以高静水压、寡营养为主要特点，该生境下的生物特征尚不明确。鞭毛旋转推进细胞运动，是细菌最有效的运动方式之一，对细胞寻找营养物质以及个体生存至关重要。细菌鞭毛合成及运动对压力变化非常敏感。对生活在水深2000-3000米处的中度嗜压菌的研究表明，不同菌株的鞭毛合成调控系统对高压环境的适应方式不同。而深渊环境中的严格嗜压菌的鞭毛合成过程及其如何适应高压环境仍未知。本项目首次以分离自10898米水深的深渊严格嗜压菌Moritella yayanosii DB21MT-5为研究对象，利用高压模拟细菌培养平台、高压显微观察仓和常规分子生物学、生物化学手段，系统解析不同压力培养和不同生长阶段的细胞的鞭毛基因转录、蛋白转运组装以及细胞运动特征，分析压力变化对鞭毛运动的影响，探索严格嗜压细菌的鞭毛系统对高压环境的适应机制，为深入揭示深渊环境中的生命过程奠定基础。

The trench, representing the deep-sea bottom with over 6000m in depth, is characterized by high hydrostatic pressure and limited nutrient supply. It remains one of the least understood habitats on earth. Flagella provide bacteria with a highly efficient means of locomotion, plays important role in searching for nutrient and cellular survival. The synthesis of flagellar and cell motility is one of the most pressure-sensitive bioprocess. As demonstrated by the study of moderately piezophiles isolated at the depth of 2000-3000 meters, the regulation of flagellar synthesis adapts to high pressure environment through various ways. However, the adaptation mechanism of flagellar from obligately piezophiles is still unclear. In the grant proposal, we will characterize the flagellar apparatus of obligately piezophilic bacteria Moritella yayanosii DB21MT-5, and study the effect of pressure on its synthesis and motility by analyzing the transcription of related genes, the translocation and assembly of proteins, and the cellular motility. The results obtained will contribute to our understanding of the adaptation mechanism of flagellar motility in obligately piezophiles to the highest hydrostatic pressure, and will shed light on the exploration of life in the deep biosphere.