Ellen Garvie examined nineteen strains of Gram-positive cocci isolated from wine and belonging to the genus Leuconostoc. These strains exhibited unique characteristics that distinguished them from other known Leuconostoc species, warranting designation as a new species named Leuconostoc oenos. The key distinguishing feature was their ability to grow in acidic media with pH values too low for other Leuconostoc species to initiate growth, particularly in tomato juice-containing media rather than standard yeast glucose citrate broth. L. oenos strains produced D(-)-lactic acid, did not synthesize dextran from sucrose, and showed specific fermentation patterns: they consistently fermented fructose, glucose, trehalose, and aesculin, frequently fermented melibiose and salicin, sometimes fermented arabinose, xylose, galactose, mannose, and cellobiose, but never fermented lactose, maltose, sucrose, raffinose, dextrin, glycerol, mannitol, or sorbitol. The strains required cysteine hydrochloride supplementation for optimal growth in some cases and demonstrated greater tolerance to ethanol compared to other Leuconostoc species. NCDO 1674 was proposed as the type strain.

Key findings

• L. oenos grows well at pH 3.7-4.8, distinguishing it from other Leuconostoc species which require pH 6.7 or higher for growth
• L. oenos does not produce dextran from sucrose and fails to ferment lactose and maltose, unlike most other Leuconostoc species
• L. oenos strains were isolated from wine sources worldwide and showed acid tolerance linked to classical biochemical differences used for lactic acid bacteria classification
• All nineteen L. oenos strains were Gram-positive, catalase-negative, formed D(-)-lactic acid, and produced gas from glucose
• L. oenos demonstrated greater ethanol tolerance than other Leuconostoc species, consistent with wine fermentation environments