Summary
Molecular based and traditional microbiological techniques were utilized to determine thestructure and degree of cold adaptation of a variety of Antarctic bacterial communities.These studies were performed to obtain a better understanding of Antarctic ecosystems andprokaryotic adaptations to low temperature. A high degree of novel diversity was foundassociated with sea ice communities, marine-derived lake sediments, and quartz stonesubliths. 16S rDNA-based clone library analysis of samples from these sites contained manyclones exhibiting novelty at the genus and family-level, and occasionally at the division-level.Most (non-thermophilic) bacterial phylogenetic divisions were represented. Sedimentfrom hyposaline Clear Lake (Vestfold Hills) contained highly unusual archaeal clonespossibly representing a novel kingdom. Evidence based on cultivation work indicated quartzstone subliths like sea ice are havens for psychrophilic bacteria. The culturability of bacteriafrom sea ice communities was also demonstrated to be surprisingly high with molecular datamatching cultivation data.