深海嗜压细菌Pseudodesulfovibrio indicus J2 通过谷氨酸代谢适应高压环境的机制

Deep-sea environments are characterized by high hydrostatic pressure. Piezophilic bacteria Pseudodesulfovibrio (Desulfovibrio) from deep-sea environments are able to cope with high hydrostatic pressure by accumulating the “piezolyte” glutamate, but little is known about the molecular mechanisms. This project will focus on examining the hydrostatic pressure adaptive mechanism based on glutamate metabolism in piezophilic bacterium Pseudodesulfovibrio indicus J2, which was isolated from a deep-sea hydrothermal area of the Indian Ocean. The detailed studies are as follow: analyses of genes involved in glutamate metabolism, regulation, signal transduction and pressure sensing through combined transcriptomics and genomics research. Molecular study will also be carried to specify the function of some important genes. The aim of this study is to elucidate the hydrostatic pressure adaptive mechanisms through glutamate metabolism in strain J2, and to help us draw a more accurate picture of the molecular mechanisms by piezolyte accumulation in deep-sea piezophiles. Results from this study will provide scientific guidance for cultivation of uncultured piezophiles and increase our understanding of their ecological role in the deep ocean.

高静水压是深海环境的一个显著特征，深海来源的嗜压细菌Pseudodesulfovibrio（Desulfovibrio）能够通过在胞内积累“压力调节因子”谷氨酸的方式适应高压环境，然而其具体的分子机制尚不清楚。本项目以一株分离自印度洋深海热液区的嗜压细菌Pseudodesulfovibrio indicus J2为研究对象，对其通过谷氨酸代谢适应高压环境的分子机制进行研究。具体研究内容包括：通过转录组学和基因组学联合的手段，分析可能参与谷氨酸代谢及相关转录调控、信号传导、压力感应等过程的基因，并进一步运用分子生物学手段对其中重要的基因进行功能研究。本项目旨在揭示嗜压细菌J2通过谷氨酸代谢途径适应高静水压的分子机制，研究结果将有助于认识深海嗜压微生物通过压力调节因子适应高压环境的机制及其在深海环境的生态作用，还可能为未培养嗜压微生物的分离培养提供指导。

本项目通过对深海嗜压菌Pseudodesulfovibrio indicus J2在0.1、10和20 MPa不同压力条件下的代谢组学-蛋白质组学-基因组学等多组学联合分析研究，发现代谢物L-Glutamic acid作为该菌适应高压环境的关键压力调节因子，并发现和鉴定了L-Glutamic acid代谢调控相关的重要基因，揭示了该菌适应高压环境的生理特性和初步的分子机制。.通过代谢组学研究，发现代谢物L-Glutamic acid与深海嗜压菌P. indicus J2适应高压环境密切相关，揭示了该菌适应高压环境的代谢特性。通过蛋白质组学-基因组学联合分析研究，发现和鉴定了谷氨酸合成关键基因簇gltABC和相关趋化、调控基因hpsAB/cheW，提示其在深海嗜压菌P. indicus J2适应高压环境过程中发挥重要作用。.另外，本研究额外发现代谢物Trehalose与深海嗜压菌P. indicus J2适应高压环境密切相关。代谢物Trehalose可能作为深海嗜压菌P. indicus J2适应高压环境的压力调节因子，与L-Glutamic acid协同发挥作用。.发表2篇SCI文章，在深海嗜压菌及其环境适应性理论研究方面拥有一定的基础性贡献。