P10: Optimization of red colorants production by Penicillium purpurogenum DPUA 1275 by response surface methodology

Safety issues related to the employment of synthetic colorants have increased the interest in the production of safer colorants from natural sources. Improved cultivation technologies have allowed the use of microorganisms as an alternative source of natural colorants. In this context, the recently isolated Penicillium purpurogenum DPUA 1275, could provide an effective microbial tool for the production of red colorants. In this study it has been investigated the influence of two independent variables, sucrose and yeast extract concentration, on the red colorant in shake flasks according to a 2² central composite design. To this purpose, sucrose and yeast extract concentration varied in the ranges of 33.2-66.8 g/L and 8.64–15.36, respectively. The further conditions of fermentation were: 4.5pH, 30°C, 150 rev.min^-1 during 336 hours. The red colorant production was evaluated through the measurement of the absorbance at 490nm. The Response Surface Methodology was used to evaluate the outcome of the fermentation. The highest yield of red colorants (2.955UA_490nm) was obtained the concentration of sucrose and yeast extract were 50g/L and 12g/, respectively: these conditions produced an increase of 78% in the red colorant production. These results supported the validity of the mathematical approach adopted, as they were satisfactory close to those (2.970UA_490nm) predicted by the model. Finally, a toxicity study conducted on Artemia larvae showed the absence of toxicity in the cultural broth of Penicillium purpurogenum DPUA 1275. Our results indicate an economically advantageous way of  production red colorants for food and pharmaceutical industry.