Development of a reliable and easy method for screening Oenococcus carbohydrate consumption profile

Aims : The aim of this study was to develop a colorimetric test to determine Oenococcus carbohydrate consumption profile. Methods and results : A semi-defined growth medium which enabled efficient bacterial growth and medium acidification in the presence of glucose was developed. The inoculum size and the presence of citrate in the medium were optimized. Acidification of the medium was revealed by adding bromocresol green and was shown to be perfectly correlated with D-glucose, D-fructose, L-arabinose, D-xylose, L-rhamnose, D-cellobiose or D-trehalose consumption by 23 distinct O. oeni strains and one O. kitaharae strain (confirmed with HPLC analysis). Significance and impact of the study : Efficient bacterial growth is essential before malic acid degradation occurs in wine. The method developed here will facilitate the comparison of numerous O. oeni strains and their ability to grow by using the various carbohydrates present in wine prior to malolactic fermentation.