近日，美国哈佛医学院的Markus Basan&Severin Schink合作并取得一项新进展。经过不懈努力，他们发现饥饿细菌的生存动力学由维持质壁分离的离子稳态决定。相关研究成果已于2024年5月23日在国际知名学术期刊《自然—物理学》上发表。

据悉，在饥饿中生存的能力是细菌适应性的一个组成部分，并决定了微生物生态系统的组成、周转和生物多样性。饥饿的细菌进入一种称为质壁分离的状态，在这种状态下，它们的细胞质从细胞壁收缩。质壁分离通常被认为是一种病理性的、被动的状态，是由于缺乏ATP而自动产生的。

该研究团队提出了与传统观念相悖的新见解，他们表明维持质壁分离实际上是一种活跃的ATP消耗状态，这一状态对于饥饿状态下的生存至关重要。研究人员发现，维持质壁分离的离子稳态占据了饥饿细胞中大部分能量预算，并直接影响了饥饿时的存活率。他们构建的数学模型能够精确预测不同饥饿条件和扰动下的死亡率。基于这一研究，他们进一步开发出一种优化的饥饿培养基，这种培养基特别适合保存和移植天然微生物群落，通过维持细胞活力，有效防止物种子集的生长。

附：英文原文

Title: Survival dynamics of starving bacteria are determined by ion homeostasis that maintains plasmolysis

Author: Schink, Severin, Polk, Mark, Athaide, Edward, Mukherjee, Avik, Ammar, Constantin, Liu, Xili, Oh, Seungeun, Chang, Yu-Fang, Basan, Markus

Issue&Volume: 2024-05-23

Abstract: The ability to survive starvation is an integral part of bacterial fitness and determines composition, turnover and biodiversity in microbial ecosystems. Starving bacteria enter a state known as plasmolysis in which their cytoplasm contracts from the cell wall. Plasmolysis is often thought to be a pathological, passive condition, arising automatically from the lack of ATP. Here we show that contrary to this notion, maintaining plasmolysis is an active, ATP-consuming state that is essential for starvation survival. We show that ion homeostasis to maintain plasmolysis consumes the largest part of the energy budget of starving cells and directly determines death rates in starvation. Our mathematical model accurately predicts death rates for various starvation conditions and perturbations. This enabled the development of an optimized starvation medium that would be ideally suited for preserving and transplanting natural microbial communities by maintaining viability but preventing outgrowth of a subset of the species.

DOI: 10.1038/s41567-024-02511-2

Source: https://www.nature.com/articles/s41567-024-02511-2