Fig. 2

Fermentation kinetics of different peptides supplemented in A. niger RG0095 fermentation culture medium. a glucose consumption; b malic acid production; c malic acid productivity; d cell dry weight. Data represent the mean ± standard deviation (SD) of three independent replicates. Statistical significance was determined by Student’s t-test (n = 3). *p < 0.05, **p < 0.01