Data_Sheet_5_Diversity of Lysis-Resistant Bacteria and Archaea in the Polyextreme Environment of Salar de Huasco.PDF

The production of specialized resting cells is a remarkable strategy developed by several organisms to survive unfavorable environmental conditions. Spores are specialized resting cells that are characterized by low to absent metabolic activity and higher resistance. Spore-like cells are known from multiple groups of bacteria, which can form spores under suboptimal growth conditions (e.g., starvation). In contrast, little is known about the production of specialized resting cells in archaea. In this study, we applied a culture-independent method that uses physical and chemical lysis, to assess the diversity of lysis-resistant bacteria and archaea and compare it to the overall prokaryotic diversity (direct DNA extraction). The diversity of lysis-resistant cells was studied in the polyextreme environment of the Salar de Huasco. The Salar de Huasco is a high-altitude athalassohaline wetland in the Chilean Altiplano. Previous studies have shown a high diversity of bacteria and archaea in the Salar de Huasco, but the diversity of lysis-resistant microorganisms has never been investigated. The underlying hypothesis was that the combination of extreme abiotic conditions might favor the production of specialized resting cells. Samples were collected from sediment cores along a saline gradient and microbial mats were collected in small surrounding ponds. A significantly different diversity and composition were found in the sediment cores or microbial mats. Furthermore, our results show a high diversity of lysis-resistant cells not only in bacteria but also in archaea. The bacterial lysis-resistant fraction was distinct in comparison to the overall community. Also, the ability to survive the lysis-resistant treatment was restricted to a few groups, including known spore-forming phyla such as Firmicutes and Actinobacteria. In contrast to bacteria, lysis resistance was widely spread in archaea, hinting at a generalized resistance to lysis, which is at least comparable to the resistance of dormant cells in bacteria. The enrichment of Natrinema and Halarchaeum in the lysis-resistant fraction could hint at the production of cyst-like cells or other resistant cells. These results can guide future studies aiming to isolate and broaden the characterization of lysis-resistant archaea.

多种生物为适应恶劣的生态环境，发展出了独特的休眠细胞生产策略，该策略堪称一种卓越的生存策略。休眠孢子作为一种特殊的休眠细胞，其特征为代谢活动低至缺失，以及更高的抗逆性。从多种细菌群体中已知存在类似孢子的细胞，这些细胞在生长条件不佳（如饥饿）的情况下能够形成孢子。然而，关于古菌中特殊休眠细胞的产生了解甚少。在本研究中，我们采用了一种无需培养的独立方法，该方法利用物理和化学裂解，以评估裂解抗性细菌和古菌的多样性，并将其与总体原核生物多样性（直接DNA提取）进行比较。在多极端环境中的Salar de Huasco，我们研究了裂解抗性细胞的多样性。Salar de Huasco是智利阿尔蒂普拉诺地区的一个高海拔的干盐湖湿地。先前的研究表明，Salar de Huasco中细菌和古菌的多样性很高，但裂解抗性微生物的多样性尚未得到研究。基本假设是极端的物理化学条件可能有利于特殊休眠细胞的产生。样品从沿盐度梯度的沉积物岩芯中采集，并在周围的小池塘中收集微生物膜。在沉积物岩芯或微生物膜中发现了显著不同的多样性和组成。此外，我们的结果显示，裂解抗性细胞不仅存在于细菌中，也存在于古菌中。与总体群落相比，细菌的裂解抗性部分具有独特的特征。能够抵御裂解处理的能力仅限于少数群体，包括已知的产孢门类，如厚壁菌门和放线菌门。与细菌不同，裂解抗性在古菌中广泛存在，这暗示了古菌可能具有普遍的裂解抗性，至少与细菌中休眠细胞的抗性相当。在裂解抗性部分中Natrinema和Halarchaeum的富集可能表明了类似包囊或其他抗性细胞的产生。这些结果可为未来旨在分离和扩大裂解抗性古菌表征的研究提供指导。