Effect of pellet size and stimulating factor on the glucosamine production using Aspergillus sp. BCRC 31742

The higher GlcN production using a wild-type fungi, Aspergillus sp. BCRC 31742 cultivated under submerged fermentation was investigated. Several fermentation aspects were studied, such as pellet size, working volume, agitation rate and stimulating factor. Culture cultivation with conditions, such as pellet diameter of 2.15 mm, 50 mL working volume (250 mL T-flask), incubation at 30 °C, 200 rpm and pH 7.0 for 5 days yielded highest biomass concentration which was 33.82 g/L, with a GlcN concentration of 7.05 g/L. Methanol was found to give the best stimulatory effect in terms of GlcN concentration as compared to glutamic acid, cycloheximide and ethanol. Addition of methanol (1.5% v/v) into fermentation medium could increase GlcN content from 0.21 (control) to 0.26 g/gdw cells and led to maximum GlcN concentration of 7.48 g/L obtained.