Department of Medical Research, E-Da Hospital, Kaohsiung City 824, Taiwan.
Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County 621, Taiwan; Department of Biomedical Sciences, National Chung Cheng University, Chiayi County 621, Taiwan.
Sci Total Environ. 2023 Jan 15;856(Pt 1):159115. doi: 10.1016/j.scitotenv.2022.159115. Epub 2022 Sep 28.
Microorganisms developed a mechanism that copes with heat, acidity, and high dissolved metal concentrations that likely first evolved. The geothermal fluids emerging in the geothermal springs of Taiwan, located at a subduction zone, are still under signs of progress in the characterization of the various microbial taxonomic changes over time. However, no systematic studies have been performed to compare water, biofilms, and sediment bacterial communities and the primary driving force of dissolved and mineral substrates capable of supporting microbial metabolism. In this study, 16S rRNA gene sequencing was employed for bacterial community exploration, and their potential metabolic pathways involved from water, biofilms, and sediment samples, collected from the geothermal valley (Ti-re-ku). Metagenomic data revealed that the water samples had higher bacterial diversity and richness than biofilms and sediment samples. At the genus level, Alicyclobacillus, Thiomonas, Acidocella, Metallibacterium, Picrophilus, and Legionella were significantly abundant in the water samples. The biofilms were rich in Aciditerrimonas, Bacillus, Acidithiobacillus, and Lysinibacillus, whereas the sediment samples were abundant in Sulfobacillus. The PICRUSt2-predicted functional results revealed that heavy metal-related functions such as heavy-metal exporter system, cobalt‑zinc‑cadmium resistance, arsenical pump, high-affinity nickel-transport, and copper resistance metabolisms were significant in the water samples. Moreover, sulfur-related pathways such as thiosulfate oxidation, dissimilatory sulfate reduction, and assimilatory sulfate reduction were important in water samples, followed by biofilms and sediment. Therefore, our findings highlighted the comparative taxonomic diversity and functional composition contributions to geothermal fluid, with implications for understanding the evolution and ecological niche dimension of microbes which are the key to geothermal ecosystem function.
微生物进化出了一种机制来应对高温、酸性和高溶解金属浓度，这种机制可能是最早进化出来的。位于俯冲带的台湾温泉中涌出的地热流体，在各种微生物分类群随时间变化的特征方面仍在不断发展。然而，尚未进行系统研究来比较水、生物膜和沉积物中的细菌群落，以及能够支持微生物代谢的溶解和矿物基质的主要驱动力。在这项研究中，采用 16S rRNA 基因测序来探索细菌群落，并从地热谷（Ti-re-ku）采集的水样、生物膜和沉积物样本中探索其潜在的代谢途径。宏基因组数据分析表明，水样的细菌多样性和丰富度高于生物膜和沉积物样本。在属水平上，水样本中丰度较高的菌属为 Alicyclobacillus、Thiomonas、Acidocella、Metallibacterium、Picrophilus 和 Legionella。生物膜富含 Aciditerrimonas、Bacillus、Acidithiobacillus 和 Lysinibacillus，而沉积物样本富含 Sulfobacillus。PICRUSt2 预测的功能结果表明，重金属相关功能如重金属外排系统、钴锌镉抗性、砷泵、高亲和力镍转运和铜抗性代谢在水样中显著富集。此外，硫相关途径如硫代硫酸盐氧化、异化硫酸盐还原和同化硫酸盐还原在水样中很重要，其次是生物膜和沉积物。因此，我们的研究结果强调了地热流体中分类多样性和功能组成的比较贡献，这对于理解微生物的进化和生态位维度以及微生物是地热生态系统功能的关键具有重要意义。
