GLACIECOLA-PUNICEA GEN. NOV., SP. NOV. AND GLACIECOLA-PALLIDULA GEN. NOV., SP. NOV - PSYCHROPHILIC BACTERIA FROM ANTARCTIC SEA-ICE HABITATS

A group of pigmented, psychrophilic, strictly aerobic chemoheterotroph s isolated from sea-ice cores collected from coastal areas of eastern Antarctica University of Tasmania, was found to represent a novel 165 rRNA lineage within the gamma subclass Of the Proteobacteria, adjacent to the genus Alteromonas. The isolates are motile, Gram-negative, rod -shaped cells, which are psychrophilic and slightly halophilic, and po ssess an absolute requirement for seawater. Differences in phenotypic characteristics and DNA-DNA hybridization indicated the isolates forme d two distinct taxa which have DNA G+C contents of 44-46 mol % and 40 mol%, respectively. Whole-cell fatty acid profiles of the isolates wer e however very similar and included 16:1 omega 7c, 18:1 omega 7c, 16:0 and 17:1 omega 8c as the major fatty acid components. Overall, suffic ient differences exist to distinguish the sea-ice strains from current ly recognized bacterial genera. It is proposed the sea-ice strains rep resent a new genus, Glaciecola, which contains two species, Glaciecola punicea gen. nov., sp. nov. (ACAM 611(T)) and Glaciecola pallidula ge n. nov., sp. nov. (ACAM 615(T)).