Diversity and adaptations of deep-sea microorganisms

• Main Author: Raghukumar, C.
• Format: Book Part
• Language: English
• Published: I.K. International, New Delhi 2005
• Subjects: deep-sea microorganisms; barophilic; East Antarctica; Lake Vostok; Antarc*; Antarctica; Ice Sheet; Siberia
• Online Access: http://drs.nio.org/drs/handle/2264/171

The discovery of near fresh closed lunch box found after 11 months in the wreck of the submersible Alvin in the year 1969 opened up a Pandora’s box of microbial diversity in the deep-sea. Discovery that near-freezing temperatures, elevated hydrostatic pressures and slow decaying process at depth aided preservation opened up a whole new area of research in biology and chemistry of deep-sea waters. This unique and challenging extreme environment is home to native baro- and psychrophiles whereas some are aliens who have acquired a resident status. The presence of Proteobacteria, a gamma subgroup of Archaea cohabiting with Pseudomonas species and giant singlecelled organisms belonging to the group Xenophyophores were some of the interesting discoveries. Microorganisms have been isolated from high-pressure environment of Lake Baikal in Siberia and Lake Vostok located 3-4 km beneath ice sheet in the East Antarctica. The unique environment of deep sea, methods of collecting deep-sea sediment and water samples, isolation and culturing of microorganisms under in situ pressure and temperature conditions are described here. The effect of elevated hydrostatic pressure on barotolerant forms and adaptation mechanisms in barophiles are discussed. Cold-tolerant enzymes, natural products of potential use in human health management and environmental bioremediation using solvent-tolerant microorganisms are some of the potential biotechnological applications of these deep-sea microbes.