• RANADHIR CHAKRABORTY

      Articles written in Journal of Earth System Science

    • Geomicrobial dynamics of Trans-Himalayan sulfur–borax spring system reveals mesophilic bacteria’s resilience to high heat

      CHAYAN ROY NIBENDU MONDAL ADITYA PEKETI SVETLANA FERNANDES TARUNENDU MAPDER SAMIDA PRABHAKAR VOLVOIKAR PRABIR KUMAR HALDAR NILANJANA NANDI TANNISHA BHATTACHARYA ANINDA MAZUMDAR RANADHIR CHAKRABORTY WRIDDHIMAN GHOSH

      More Details Abstract Fulltext PDF

      Geomicrobiology of sulfur–boron-dominated, neutral-pH hydrothermal systems was revealed in a Trans-Himalayan spring named Lotus Pond, located at 4436 m, in Puga Valley, Ladakh (India), where water boils at 85$^{\circ}$C. Water sampled along Lotus Pond’s outflow (vent to an adjacent river called Rulang), representing an 85–14$^{\circ}$C gradient, had high microbial diversity and boron/chloride/sodium/sulfate/thiosulfate concentration; potassium/silicon/sulfide/sulfite was moderately abundant, whereas cesium/lithium small but definite. Majority of the bacterial genera identified in the 85–72$^{\circ}$C samples have no laboratory-growth reported at >45$^{\circ}$C, and some of those mesophiles were culturable. Sulfur-species concentration and isotope-ratio along the hydrothermal gradient, together with the distribution of genera having sulfur-oxidizing members, indicated chemolithotrophic activities in the 85–72$^{\circ}$C sites. While biodiversity increased in the vent-to-river trajectory all-day, maximum rise was invariably between the vent (85–81$^{\circ}$C) and the 78–72$^{\circ}$C site; below 72$^{\circ}$C, diversity increased gradually. Biodiversity of the vent-water exhibited diurnal fluxes relatable to the sub-surface-processes-driven temporal fluxes in physicochemical properties of the discharge. Snow-melts infiltrating (via tectonic faults) the $\sim$160$^{\circ}$C geothermal reservoir located within the breccia, at $\sim$450 m depth, apparently transport mesophilic microbes into the thermal waters. As these micro-organisms emanate with the vent-water, some remain alive, illustrating that natural bacterial populations are more heat-resilient than their laboratory counterparts.

    • Indus and Nubra Valley hot springs aaffirm the geomicrobiological specialties of Trans-Himalayan hydrothermal systems

      NIBENDU MONDAL ADITYA PEKETI TARUNENDU MAPDER CHAYAN ROY ANINDA MAZUMDAR RANADHIR CHAKRABORTY WRIDDHIMAN GHOSH

      More Details Abstract Fulltext PDF

      Geomicrobiologies of the hot springs of Chumathang and Panamik (located in the Indus and Nubra valleys of eastern and northern Ladakh, respectively) were revealed and compared with the Lotus Pond spring of Puga Valley (eastern Ladakh), which is known for its mineralogical and ecological peculiarities. Physicochemically, the vent-waters of the explored springs, Chumathang_01, Panamik_01 and Panamik_02, were distinct from Lotus Pond, with wide variations in boron, chloride, lithium, magnesium and potassium concentrations. Their microbiomes encompassed several unique constituents, but resembled Lotus Pond in being highly diversified and bacterial-mesophiles-dominated. Higher diversities of thermophilic archaea were detected in Chumathang_01 compared to Panamik_01 or Panamik_02. Statistical analysis of the geochemical and microbiological data highlighted the overall uniqueness of Lotus Pond, the constraint imposed by high temperature on the diversity of most bacterial groups, and the potential role of in-situ geochemicals in helping mesophilic bacteria inhabit the high-temperature environments. While the microbiome architecture of the 86°C Chumathang_01 (having the highest bacterial species count) closely resembled that of the geochemically similar 78°C Panamik_01, both the biomes were apparently shaped by temperature and pH. In contrast, the distinctive geochemistry of the 81°C Lotus Pond was apparently instrumental in sustaining a microbiome similar to that of the cooler (70°C) Panamik_02.

  • Journal of Earth System Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.