High Variation in Protist Diversity and Community Composition in Surface Sediment of Hot Springs in Himalayan Geothermal Belt, China

Abstract

Hot springs are some of the most special environments on Earth. Many prokaryotic and eukaryotic microbes have been found to live in this environment. The Himalayan geothermal belt (HGB) has numerous hot springs spread across the area. Comprehensive research using molecular techniques to investigate eukaryotic microorganisms is still lacking; investigating the composition and diversity of eukaryotic microorganisms such as protists in the hot spring ecosystems will not only provide critical information on the adaptations of protists to extreme conditions, but could also give valuable contributions to the global knowledge of biogeographic diversity. In this study, we used high-throughput sequencing to illuminate the diversity and composition pattern of protist communities in 41 geothermal springs across the HGB on the Tibetan Plateau. A total of 1238 amplicon sequence variants (ASVs) of protists were identified in the hot springs of the HGB. In general, Cercozoa was the phylum with the highest richness, and Bacillariophyta was the phylum with the highest relative abundance in protists. Based on the occurrence of protist ASVs, most of them are rare. A high variation in protist diversity was found in the hot springs of the HGB. The high variation in protist diversity may be due to the different in environmental conditions of these hot springs. Temperature, salinity, and pH are the most important environmental factors that affect the protist communities in the surface sediments of the hot springs in the HGB. In summary, this study provides the first comprehensive study of the composition and diversity of protists in the hot springs of the HGB and facilitates our understanding of the adaptation of protists in these extreme habitats.

Amplicon Barcoding Based Sequencing Reveals Bacterial Diversity From Himalayan Hotspring of Kotli Azad Jammu and Kashmir

“…In a study, high variation in microbial diversity was found in the hot springs of the Himalayan Geothermal Belt in China. The high variation in microbial diversity is ascribed to the different in environmental conditions (temperature, salinity, and pH) of these hot springs [47].…”

Aquificae overcomes competition by archaeal thermophiles, and crowding by bacterial mesophiles, to dominate the boiling vent-water of a Trans-Himalayan sulfur-borax spring

“…Idiosyncratic to the above community structure axiomatic for hydrothermal ecosystems, a geochemically unusual category of Trans-Himalayan hot springs (poor in total dissolved solids including silicon, but rich in boron, sodium and diverse sulfur species), located on the either side of the tectonically active Indus Tsangpo Suture Zone (ITSZ, the collision intersection between the Asian and Indian continental crusts engaged in Himalayan orogeny) in eastern Ladakh, India [13–16], have been reported to feature extra-ordinarily high habitability [5, 10, 17, 18]. Concurrent to such reports of exceedingly bio-diverse microbiomes from the springs of the Puga and Chumathang geothermal areas situated on the Changthang plateau in the south and north of the ITSZ respectively, studies of microbial diversity within the vent-waters, and vent-adjacent niches, of a number of hot springs located across discrete Himalayan and Trans-Himalayan geothermal regions have corroborated that hydrothermal environments were not “Thermophiles Only Territories” [19–26].…”

“…Compared with other well studied hydrothermal systems, the geochemical specialty of these Trans-Himalayan hot springs lies in their paucity of dissolved solids in general and calcium and silicon in particular, which again is accompanied by the exceptional abundance of boron, chlorine, sodium, and various sulfur species including both sulfide and sulfate. Concurrent to such reports of highly bio-diverse microbiomes from the hot springs of the Puga valley and Chumathang geothermal areas situated on the Changthang plateau, to the south and north of the ITSZ respectively, studies of microbial diversity within the vent-waters, and vent-adjacent areas, of a number of hot springs located across discrete Himalayan and Trans-Himalayan geothermal regions have corroborated that hydrothermal environments are not “Thermophiles only” territories [19–26].…”