Water and soil samples from Schirmacher Oasis, Antarctica were found to contain a heterogenous group of psychrotrophic bacteria and yeasts. The bacteria belong to the genera Pseudomonas, Sphingobacteriwn, Micrococcus, Planococcus and Arthrobacter. The yeasts belong to the genera Rhodotorula, Bullera and Candida. Biochemical studies indicate that these psychrotrophs are capable of both translation and transcription even at 0β and have enzymes which are cold-active, heat-labile and freeze-thaw resistant. Carotenoid pigments which interact with the bacterial membranes have been implicated in cold adaptation. Plasmids with antibiotic resistant genes have also been detected in some of the bacteria. All the results are discussed with a view to obtain possible insight into the biological basis of adaptation of microorganisms to low temperatures
