Oribacterium parvum sp. nov. and Oribacterium asaccharolyticum sp. nov., obligately anaerobic bacteria from the human oral cavity, and emended description of the genus Oribacterium.

Three strictly anaerobic, Gram-positive, non-spore-forming, rod-shaped, motile bacteria, designated strains ACB1(T), ACB7(T) and ACB8, were isolated from human subgingival dental plaque. All strains required yeast extract for growth. Strains ACB1(T) and ACB8 were able to grow on glucose, lactose, maltose, maltodextrin and raffinose; strain ACB7(T) grew weakly on sucrose only.

Stomatobaculum longum gen. nov., sp. nov., an obligately anaerobic bacterium from the human oral cavity.

A strictly anaerobic Gram-stain-variable but positive by structure, non-spore-forming bacterium designated Lachnospiraceae bacterium ACC2 strain DSM 24645(T) was isolated from human subgingival dental plaque. Bacterial cells were 4-40 µm long non-motile rods, often swollen and forming curved filaments up to 200 µm. Cells contained intracellular, poorly crystalline, nanometre-sized iron- and sulfur-rich particles.

Class Cariacotrichea, a novel ciliate taxon from the anoxic Cariaco Basin, Venezuela.

The majority of environmental micro-organisms identified with the rRNA approach have never been visualized. Thus, their reliable classification and taxonomic assignment is often difficult or even impossible. In our preliminary 18S rRNA gene sequencing work from the world's largest anoxic marine environment, the Cariaco Basin (Caribbean Sea, Venezuela), we detected a ciliate clade, designated previously as CAR_H [Stoeck, S.