Keywords
Abstract
Malolactic fermentation (MlF) is the only useful process of all
caused in wine by lactic acid bacteria. Enzymatic transformation
of dibasic l-malic acid into monobasic l-lactic acid and carbon
dioxide enters as the key metabolic characteristic of MlF, which
leads to deacidification of wine. capability of 39 native lactic acid
strains of the genera Leuconostoc and Lactobacillus to assimilate
l-malic acid was studied using conventional methods and approaches of microbiology of wine. the capability of the study
strains to conduct MlF was tested by l-malic acid utilization for
maintaining viability of non-fissiparous cells. l-malic acid utilization was calculated by changes in titratable acidity of medium
during cultivation of the study strains. this was preceded by a
mathematical treatment of a set of estimated characteristics of
binary systems established based on the variation of malic to lactic
acid ratios. lactic acid strains promising for MlF were selected
following a two-step screening during which the growth of the
study strains and their activity with refer to l-malic acid assimilation were evaluated. the time-course of growth was longer in
lactic acid strains of Leuconostoc than in those of Lactobacillus.
the growth dynamics of a total of 88 native lactic acid strains
was assessed, and 39 strains with a high growth efficiency were
selected. Strain-dependant cell biomass accumulation of these
strains was around 108-109 cells/cm3 after 24-48 h of cultivation.
a sufficiently high activity with refer to l-malic acid assimilation
was found in the majority of the 39 native lactic acid strains tested
for potential capability to conduct malolactic fermentation. this
feature was observed in 94 % of the studied coccal form of lactic
acid bacteria, which proves that they are typical agents of malolactic fermentation for winemaking, and in not more than 50% of
the study lactic acid bacteria of Lactobacillus. nevertheless, the
prospects for their use as active deacidifiers are also high.