Deep subsurface samples recovered from Deccan traps Targeted loci environmental

Exploration of bacterial and archeal diversity and understating the pattern of co-occurrence of various groups within deep biosphere of igneous crustal systems represent the emerging frontiers of deep life initiatives; unraveling the composition of microbial dark matter, limits of life, mechanisms of microbial interaction with inorganic environment and adaptation within the aphotic, oligotrophic igneous provinces of Earth crust is scientifically intriguing, addressing several fundamental questions related to evolution and functioning of life in our planet and beyond. Compared to a reasonable level of understanding of microbial community structure and function as well as energetic foundations within marine and terrestrial subsurface sedimentary ecosystems; geomicrobiology of basalts and underneath bed rocks at higher depths remain little explored. Microbial diversity is low in such environments due to oligotrophic conditions. It has been found that the igneous rock systems in deep subsurface are limited in photosynthetically derived carbon and generally host the chemolithoautotrophic ecosystems founded upon biological methanogenesis/acetogenesis and supported by geological H2 production and inorganic C. However, relatively little is known about the processes that regulate diversity and distribution of microbial species within such deep crustal systems, limits of life within such environment and microbial role in interaction with granitic rocks and cycling of elements. It is necessary to understand the functional profile of the environment as well as its phylogenetic profile. PI Pinaki Sar, Indian Institute of Technology Kharagpur