Chemosynthetic activity prevails in deep-sea sediments of the Central Indian Basin

It is hypothesized that in the deep-sea, under psychrophilic, barophilic and oligotrophic conditions, microbial community of Central Indian Basin (CIB) sediments could be chemosynthetic. In the dark, at near ambient temperature, 4 ± 2°C, 500 atm pressure, pelagic red clay could fix carbon at rates ranging from 100 to 500 nmol C g −1 dry wt day −1 . These clays accumulate in the deepest and the most remote areas of the ocean and contain