Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.
Department of Bionanoscience, Delft University of Technology, Delft, the Netherlands.
Nat Microbiol. 2020 Jul;5(7):943-954. doi: 10.1038/s41564-020-0704-2. Epub 2020 Apr 20.
The conventional view is that high temperatures cause microorganisms to replicate slowly or die. In this view, microorganisms autonomously combat heat-induced damages. However, microorganisms co-exist with each other, which raises the underexplored and timely question of whether microorganisms can cooperatively combat heat-induced damages at high temperatures. Here, we use the budding yeast Saccharomyces cerevisiae to show that cells can help each other and their future generations to survive and replicate at high temperatures. As a consequence, even at the same temperature, a yeast population can exponentially grow, never grow or grow after unpredictable durations (hours to days) of stasis, depending on its population density. Through the same mechanism, yeasts collectively delay and can eventually stop their approach to extinction, with higher population densities stopping faster. These features arise from yeasts secreting and extracellularly accumulating glutathione-a ubiquitous heat-damage-preventing antioxidant. We show that the secretion of glutathione, which eliminates harmful extracellular chemicals, is both necessary and sufficient for yeasts to collectively survive at high temperatures. A mathematical model, which is generally applicable to any cells that cooperatively replicate by secreting molecules, recapitulates all of these features. Our study demonstrates how organisms can cooperatively define and extend the boundaries of life-permitting temperatures.
传统观点认为，高温会导致微生物缓慢繁殖或死亡。在这种观点中，微生物会自主对抗热诱导的损伤。然而，微生物彼此共存，这就提出了一个尚未得到充分探讨的及时问题，即在高温下，微生物是否可以协同对抗热诱导的损伤。在这里，我们使用 budding yeast Saccharomyces cerevisiae 来表明细胞可以相互帮助，以及它们的后代在高温下生存和繁殖。因此，即使在相同的温度下，取决于种群密度，酵母种群可以指数级增长，从不生长或在不可预测的静止期（数小时到数天）后生长。通过相同的机制，酵母集体延迟并最终停止接近灭绝，较高的种群密度会更快地停止。这些特征源于酵母分泌并细胞外积累谷胱甘肽——一种普遍存在的防止热损伤的抗氧化剂。我们表明，谷胱甘肽的分泌，即消除有害的细胞外化学物质，对于酵母在高温下集体生存是必要和充分的。一个普遍适用于通过分泌分子进行协同复制的任何细胞的数学模型，概括了所有这些特征。我们的研究表明了生物体如何协作定义和扩展允许的生存温度范围。
