Differentiation of Australian wine isolates of Oenococcus oeni using random amplified polymorphic DNA (RAPD)

Intraspecific variation of Oenococcus oeni , the preferred lactic acid bacteria species for inducing malolactic fermentation in wine, was studied using the randomly amplified polymorphic DNA (RAPD) strain fingerprinting technique. Ten of fifteen isolates of O. oeni from Australian wineries situated in different wine regions could be distinguished by the RAPD technique. Strains of O. oeni which originated from the same winery were either indistinguishable or closely related to each other. Six different commercially available O. oeni strains could be differentiated with the four RAPD primers used and their genetic similarity determined. Analysis of O. oeni present in wines from a single source of fruit (Cabernet Sauvignon, vintage 2002) that underwent spontaneous malolactic fermentation revealed wide genetic variation amongst the isolates. Each fermentor contained several different O. oeni strains, which were present throughout alcoholic and malolactic fermentation. These data highlight the sensitivity of RAPDs when suitable primers are applied to O. oeni of unknown genetic origin, thus enabling O. oeni strains with desirable sensory and fermentation properties to be genetically analysed.