The fermentation result of Lac131 was shown in Fig. 4. The initial fermentation consumed40 g L−1 glucose after 17 h. The wet weight and the crude enzymatic activity were 78.35 g L−1and 109.84 U mL−1, respectively, at this time point. Afterwards, the cells grew rapidly due tothe supply of carbon and nitrogen. After 60 h, the wet weight increased slowly and becameequable. The crude enzyme activity showed a trend of equable increase before 96 h butbecame flat afterwards, with the activity of 4,239.07 U mL−1 and a wet weight of 472.66 g L−1at 96 h. This activity was significantly higher than that (1736.05 U mL−1) yielded by the wild-type matlac gene from the recombinant yeast although the wet weight profiles were similar.The activity was almost eight folds higher than that of A. oryzae genetic engineering strainconstructed by Berka et al