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

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