Proposal of Quinella ovalis gen. nov., sp. nov., based on phylogenetic analysis

Quin's oval is a relatively large bacterium often seen in the rumens of sheep fed diets containing some readily fermented carbohydrates. It has not been obtained in axenic cultures, but a number of its features have been determined by various methods, such as studying cell suspensions purified from rumen fluid by differential centrifugation. We obtained similarly purified suspensions from a sheep fed a diet containing a large amount of molasses. Nearly complete 16S rRNA sequence analysis of these cells as well as cells as Selenomonas ruminantium subsp. ruminantium GA192 (ATCC 12561; type strain) and S. ruminantium subsp. lactilytica HD4 (ATCC 27209) was done. These sequences were compared with those of other bacteria. Evolutionary distance estimates indicated that Quin's oval was most closely related to the Selenomonas-Megasphaera-Sporomusa group in the gram-positive phylum but that it belongs in a new genus. We propose the name Quinella ovalis gen. nov., sp. nov., with its description based on previously known features.