加利福尼亚最大的湖泊索尔顿海（Salton Sea）内硫循环嗜盐菌的多样性。

Diversity of sulfur cycling halophiles within the Salton Sea, California's largest lake.

作者信息

Freund Linton, Hung Caroline, Topacio Talyssa M, Diamond Charles, Fresquez Alyson, Lyons Timothy W, Aronson Emma L

机构信息

Genetics, Genomics, and Bioinformatics Program, University of California, Riverside, 900 University Ave, Riverside, CA, 92521, USA.

Department of Earth and Planetary Sciences, University of California, Riverside, 900 University Ave, Riverside, CA, 92521, USA.

出版信息

BMC Microbiol. 2025 Mar 6;25(1):120. doi: 10.1186/s12866-025-03839-2.

DOI:10.1186/s12866-025-03839-2

PMID:40045185

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11883979/

Abstract

BACKGROUND

Microorganisms are the biotic foundation for nutrient cycling across ecosystems, and their assembly is often based on the nutrient availability of their environment. Though previous research has explored the seasonal lake turnover and geochemical cycling within the Salton Sea, California's largest lake, the microbial community of this declining ecosystem has been largely overlooked. We collected seawater from a single location within the Salton Sea at 0 m, 3 m, 4 m, 5 m, 7 m, 9 m, 10 m, and 10.5 m depths in August 2021, December 2021, and April 2022.

RESULTS

We observed that the water column microbiome significantly varied by season (R = 0.59, P = 0.003). Temperature (R = 0.27, P = 0.004), dissolved organic matter (R = 0.13, P = 0.004), and dissolved oxygen (R = 0.089, P = 0.004) were significant drivers of seasonal changes in microbial composition. In addition, several halophilic mixotrophs and other extremotolerant bacteria were consistently identified in samples across depths and time points, though their relative abundances fluctuated by season. We found that while sulfur cycling genes were present in all metagenomes, their relative coverages fluctuated by pathway and season throughout the water column. Sulfur oxidation and incomplete sulfur oxidation pathways were conserved in the microbiome across seasons.

CONCLUSIONS

Our work demonstrates that the microbiome within the Salton Seawater has the capacity to metabolize sulfur species and utilize multiple trophic strategies, such as alternating between chemorganotrophy and chemolithoautrophy, to survive this harsh, fluctuating environment. Together, these results suggest that the Salton Sea microbiome is integral in the geochemical cycling of this ever-changing ecosystem and thus contributes to the seasonal dynamics of the Salton Sea. Further work is required to understand how these environmental bacteria are implicated relationship between the Salton Sea's sulfur cycle, dust proliferation, and respiratory distress experienced by the local population.

摘要

背景

微生物是生态系统中养分循环的生物基础，其群落组成通常基于所处环境的养分可利用性。尽管此前的研究已经探讨了加利福尼亚最大的湖泊索尔顿海内部的季节性湖水翻转和地球化学循环，但这个生态系统不断衰退的微生物群落很大程度上被忽视了。我们于2021年8月、2021年12月和2022年4月，从索尔顿海0米、3米、4米、5米、7米、9米、10米和10.5米深度的单个位置采集了海水样本。

结果

我们观察到水柱微生物群落随季节有显著变化（R = 0.59，P = 0.003）。温度（R = 0.27，P = 0.004）、溶解有机物（R = 0.13，P = 0.004）和溶解氧（R = 0.089，P = 0.004）是微生物组成季节性变化的重要驱动因素。此外，在不同深度和时间点的样本中，始终能鉴定出几种嗜盐混合营养菌和其他极端耐受细菌，尽管它们的相对丰度随季节波动。我们发现，虽然所有宏基因组中都存在硫循环基因，但其相对覆盖率在整个水柱中随途径和季节而波动。硫氧化和不完全硫氧化途径在不同季节的微生物群落中是保守的。

结论

我们的研究表明，索尔顿海海水中的微生物群落有能力代谢含硫物质，并利用多种营养策略，如在有机营养和化能自养之间交替，以在这个恶劣多变的环境中生存。这些结果共同表明，索尔顿海微生物群落在这个不断变化的生态系统的地球化学循环中不可或缺，从而影响索尔顿海的季节性动态。需要进一步开展工作，以了解这些环境细菌与索尔顿海的硫循环、沙尘扩散以及当地居民所经历的呼吸窘迫之间的关系。