Predominance of malolactic fermentation over d-glucose utilization in Lactobacillus plantarum and Lactobacillus curvatus wine strains

Abstract

Two selected wine strains of the genus Lactobacillus (L. plantarum 197 and L. curvatus 783) were tested for their ability to complete malolactic fermentation (MLF) in a synthetic medium (PBM-broth) supplemented with L-malic acid (7.5-74.6 mM) and D-glucose (5.5-55 mM). The 24 directed fermentation assays, 12 for each bacterial strain, were carried out at 20°C and pH 3.5. MLF was completed (residual L-malic acid ≤0.2 mM) in eight days in 19 of the 24 fermentation assays, even in the presence of 74.6 mM L-malic acid or 55.5 mM D-Glucose utilization was generally simultaneous to MLF but was completed (residual concentrations ≤0.2 mM) only in 6 of the 24 fermentation assays. These results support the use of these strains in directed MLF assays at the very different L-malic acid and D-glucose concentrations tested. © 1993 Society for Industrial Microbiology.