Leuconostoc's a genus of Gram-positive bacteria, placed within the family of Leuconostocaceae. They're generally ovoid cocci often forming chains. Leuconostoc sp. are intrinsically resistant to vancomycin and are catalase-negative (which distinguishes them from staphylococci). All species within this genus are heterofermentative and are able to produce dextran from sucrose. They're generally slime-forming. Blamed for causing the 'stink' when creating a sourdough starter, some species are also c… (More on Leuconostoc)