Evaluation of a new fluorimetric DNA-DNA hybridization method.

Standardized procedures must be followed when characterizing, officially describing, and validly naming novel bacteria. For species descriptions, DNA-DNA hybridization still is needed for whole-genome comparisons between close relatives, but many established hybridization methods have drawbacks, such as requiring labeled or large amounts of DNA. We evaluated a new technique based on the spectrophotometric method in which renaturation rates are used for calculating the degree of binding, which estimates relatedness.

Novel ultramicrobacterial isolates from a deep Greenland ice core represent a proposed new species, Chryseobacterium greenlandense sp. nov.

Three novel orange, ultramicrobacterial isolates, UMB10, UMB14, and UMB34(T) were isolated from enrichment cultures inoculated with a melted 3,043 m deep Greenland ice core sample. Phylogenetic analysis of the 16S rRNA gene sequences indicated that the isolates belonged to a single species within the genus Chryseobacterium. They were most closely related to Chryseobacterium aquaticum (99.

Herminiimonas glaciei sp. nov., a novel ultramicrobacterium from 3042 m deep Greenland glacial ice.

A Gram-negative ultramicrobacterium (designated strain UMB49(T)) was isolated from a 120,000-year-old, 3,042 m deep Greenland glacier ice core using a 0.2 mum filtration enrichment procedure. Phylogenetic analysis of the 16S rRNA gene sequence indicated that this strain belonged to the genus Herminiimonas of the family Oxalobacteraceae of the class Betaproteobacteria.

Biochemical characterization of a beta-galactosidase with a low temperature optimum obtained from an Antarctic arthrobacter isolate.

A psychrophilic gram-positive isolate was obtained from Antarctic Dry Valley soil. It utilized lactose, had a rod-coccus cycle, and contained lysine as the diamino acid in its cell wall. Consistent with these physiological traits, the 16S ribosomal DNA sequence showed that it was phylogenetically related to other Arthrobacter species.

Rhodoglobus vestalii gen. nov., sp. nov., a novel psychrophilic organism isolated from an Antarctic Dry Valley lake.

A novel, psychrophilic, gram-positive bacterium (designated strain LV3T) from a lake near the McMurdo Ice Shelf, Antarctica, has been isolated and characterized. This organism formed red-pigmented colonies, had an optimal growth temperature of 18 degrees C and grew on a variety of media between -2 and 21 degrees C. Scanning electron micrographs of strain LV3T that showed small rods with unusual bulbous protuberances during all phases of growth were of particular interest.