High Quality Content by WIKIPEDIA articles! Oenococcus is a genus of Gram-positive bacteria, placed within the family of Leuconostocaceae. The only species in the genus used to be Oenococcus oeni (which was known as Leuconostoc oeni until 1995). In 2006, the species Oenococcus kitaharae was identified. As its name implies, Oenococcus oeni (formerly Leuconostoc oeni) holds major importance in the field of oenology, where it is the primary bacteria involved in completing the malolactic fermentation.