Archean granitic basement rock cores recovered through pilot borehole Targeted loci environmental
The present project aims to gain a better insight in to the fundamentals of carbon and other essential nutrient cycling microorganisms from deep crystalline granitic basement approximately 3000m below surface at Deccan traps, India. Microbial diversity and function within the deep Earth crust play critical roles in biogeochemical cycling of elements. In spite of their well-recognized importance in evolution and maintenance of our planet, diversity of bacteria and archaea in deep terrestrial igneous crust remained less explored. Recent scientific deep drilling upto a depth of 3000 mbs in Koyna-Warna region of Deccan traps offers an extraordinary opportunity to investigate deep life within Archean crustal system underlying Late Cretaceous Deccan traps. Microbial communities enriched from rock sample recovered from the deepest core of pilot borehole, 2900 mbs, will be analyzed based on bacteria and archaea specific 16S rRNA gene sequence analysis. Rock samples are incubated under strict anaerobic condition, at 73 C, the temperature of the rock crust, using a specially designed low nutrient alkaline medium pH 9.0. A range of carbon, sulphur, and nitrogen substrates as well as terminal electron acceptors are being used to enrich the bacterial and archaeal populations capable of utilizing the specific substrates and allow us to gain understanding on respective microbial populations involved in C-, N-, S- biogeochemical cycling and overall community function in such hot, organic carbon lean, deep crystalline system. Major objectives of this sequencing project are to elucidate the response of deep terrestrial subsurface community towards the specific C, S, N sources, electron donors and terminal electron acceptors provided and to unravel the specific bacterial and archaeal groups involved in major biogeochemical cycles within such a deep, dark, hot, highly oligotrophic, terrestrial ecosystem. PI Pinaki Sar, Indian Institute of Technology Kharagpur