INTERACTIONS BETWEEN LEUCONOSTOC-OENOS AND PEDIOCOCCUS SPP DURING VINIFICATION OF RED WINES

Strains of Pediococcus parvulus were inoculated into sterile-filtered Cabernet Sauvignon and Merlot wines in which malolactic fermentation w as either not induced (MLF (-) wines) or induced by Leuconostoc oenos (MLF (+) wines) prior to filtration. While most strains grew in MLF (- ) wines, the viability of all strains declined from an initial populat ion of ca 10(5) CFU/mL to between <300 and 10(4) CFU/mL after inoculat ion into MLF (+) wines. The initial decline in viability appears to be due to formation of an inhibitory substance(s) by L. oenos. This anta gonism was not permanent since most strains of P. parvulus eventually entered logarithmic phase of growth. Changes in pH, titratable and vol atile acidities, or acetoin (plus diacetyl) were not evident in MLF () Merlot wines. Comparison of the bouquet characteristics of wines, wi th and without the growth of P. parvulus WS-29A, indicated significant differences (p = 0.03) in the MLF (-) but not the MLF (+) Cabernet Sa uvignon wines.