FIG. 5.

Degradation of ester (A) and thioester (B) in cheese paste model system. Cells of wild-type L. lactis NZ9000 (w.t.) and L. lactis NZ9000 containing pNZ7408 (induced with 2 ng/ml nisin) at a final OD₆₀₀ of 0.5 were added to cheese paste supplemented with 5 mg/kg of ethyl-hexanoate or 150 μg/kg of S-methyl thiobutanoate. Only sodium phosphate buffer was used in the control cheese paste. The cheese paste samples were incubated at 17°C, and samples were taken at zero time and 2 weeks. The residual amounts of ester and thioester were determined by HS-GC. The error bars indicate the standard deviations of triplicate experiments.