Fig. 2
Cell density and extracellular enzyme activity of X33-YH under various culture conditions in flask fermentation. a Effect of culture pH on cell density (OD600). b Effect of pH on enzyme activity. c Effect of added methanol concentration on cell density. d Effect of added methanol concentration on enzyme activity. pH and methanol concentration had no notable effect on cell density, but did affect enzyme activity. Optimal values for Lipase-YH expression in shake-flask culture were pH 7.0–8.0 and methanol 1.0%; resulting enzyme activity was 972 U/mL