A novel strategy and kinetics analysis of half-fractional high cell density fed-batch cultivation of Zygosaccharomyces rouxii.

Zygosaccharomyces rouxii is an important microorganism for aroma production in traditional fermented foods. Using Z. rouxii as the original strain, the batch was split after glucose depletion in the culture medium. Half of the volume of the culture medium was released, and fresh culture medium was fed in. The exponential culture kinetics and the formula for the half-fractional fed-batch cultivations were determined to achieve a new strategy for high cell density culturing of Z. rouxii. Based on a full cultivation, three half-fractional fed-batch cultivations were performed after every 10 hr of culture. The specific growth rates of Z. rouxii at the different stages were in the order μ X0>μ X1>μ X2>μ X3 (0.525 to 0.229 hr-1). The glucose substrate consumption rates gradually decreased following the order μ S0>μ S1>μ S2>μ S3 (-1.165 to -0.722, g/g). The equation models for cell growth and glucose substrate consumption showed typical exponential behavior. The total cell yield was 1.78-fold higher than the yield from a full cultivation, and this continuous subculture strategy also indicated a higher efficiency than traditional full cultivation. A new strategy for highly efficient culturing of Z. rouxii was achieved in a pilot scale. A foundation with data support for the production and application of Z. rouxii was developed.