Investigating the influence of pH, temperature and agitation speed on yellow pigment production by Penicillium aculeatum ATCC 10409

In this study, the combined effect of pH, temperature and agitation speed on yellow pigment production and mycelial growth of Penicillium aculeatum ATCC 10409 was investigated in whey media. Different pH levels (5, 6.5 and 8), temperatures (25, 30 and 35 degrees C) and agitation speed levels (100 and 150rpm) were tested to determine the best conditions to produce a fungal yellow pigment under submerged fermentation. The best production of yellow pigment (1.38g/L) was obtained with a pH value of 6.5, a temperature of 30 degrees C and an agitation speed of 150rpm. In contrast, the maximal biomass concentration (11.12g/L) was obtained at pH value of 8, a temperature of 30 degrees C and an agitation speed of 100rpm. These results demonstrated that biomass and yellow pigment production were not directly associated. The identification of the structure of unknown P. aculeatum yellow pigment was detected using UV absorption spectrum and FT-IR spectroscopy.