Study on application of a strain of Kloeckera apiculata KY-13c with killer performance

Fermentation characteristics of killer yeast KY-13c(Kloeckeera apiculate) isolated from a persimmon orchard were investigated for possible use in persimmon wine production. The growth and killer ability of KY-13 c were analyzed under different p H,temperatures,alcohol contents and sugar degrees. Furthermore,its fermentation ability and inhibition function on sensitive yeast TJ09( Hanseniospora uvarum) in fermentation liquid were also studied. The results showed that the optimal growth condition for KY-13 c was p H5.5,temperature30 ℃,and 10% reducing sugar in the fermentation liquid and its optimal killer ability was observed under conditions of p H6.0,temperature 35 ℃,and 10% reducing sugar in the fermentation liquid. Alcohol accumulation during fermentation process resulted in inhibition on both growth and killer ability of KY-13 c. Nevertheless,KY-13 c reformed new dominated growth as indicated by its number reached 1010CFU/m L within 5 days after its activated culture being inoculated by 10% to the end-of-logarithmic fermentation liquid of sensitive yeast strain TJ09. And on the 8th day after the inoculation,KY-13 c showed strong fermentation capacity with residual sugar and carbon dioxide loss values stable at 3.1 g/L and 5.6 g/L,respectively.