Propionispora hippei sp. nov., a novel Gram-negative, spore-forming anaerobe that produces propionic acid

A Gram-negative, spore-forming anaerobe, KS(T), was isolated from an enrichment culture that was set up for anaerobic degradation of the aliphatic polyester poly(propylene adipate). The strain had the cellular organization of Sporomusa, vibrio-shaped cells and terminal round spores, and fermented sugars and sugar alcohols to propionic and acetic acid. Based on the morphological and physiological features as well as on a 16S rRNA gene similarity of 98 %, it was grouped with Propionispora vibrioides. A relatively low DNA-DNA hybridization value with the type strain of this species (47 %), and differences in substrate utilization and spore morphology, suggested that the strain should be classified in a separate species, Propionispora hippei sp. nov., with KS(T) as the type strain (=DSM 15287(T)=ATCC BAA-665(T)).