3.3 Effect of nutritional parameters on colorant production
To study the effect of the alterations in the nutritional parameters on colorant production, the strains Penicillium gravinicaseiP3SO332, Clonostachys rosea P2SO329 and Penicilliumsclerotiorum P3SO224 were grown in Czapeck medium base that was modified with different sources of carbon or nitrogen (Fig. 3).
Colorant production was achieved when maize starch was used as a carbon source and peptone as a nitrogen source in the submerged bioprocess forPenicillium gravinicasei P3SO332 (Fig. 3 A, B,). Glucose and maize starch were the carbon sources that allowed the highest absorbances and yeast extract was the best nitrogen source forClonostachys rosea P2SO329 at the analyzed wavelength (Fig. 3 C, D). Maximum absorbance was observed in the submerged bioprocess that contained sucrose as a source of carbon and yeast extract as a source of nitrogen in Penicillium sclerotiorum P3SO224 (Fig. 3 E, F).
Based on the above results, glucose (Clonostachys rosea P2SO329), sucrose (Penicillium sclerotiorum P3SO224) and maize starch (Penicillium gravinicasei P3SO332) were selected as carbon sources and, as nitrogen sources, yeast extract (Clonostachys rosea P2SO329, Penicilliumsclerotiorum P3SO224) and peptone (Penicilliumgravinicasei P3SO332) were selected. The optimal production conditions for the three selected isolates were evaluated for 20 days.
Clonostachys rosea P2SO329, Penicillium sclerotiorumP3SO224 and Penicillium gravinicasei P3SO332 presented their maximum production of colorants at 15, 10 and 20 days, respectively. The maximum production of biomass was observed at 20 days byClonostachys rosea P2SO329 (5.14 g/L), Penicillium sclerotiorum P3SO224 (8.62 g/L) and Penicillium gravinicaseiP3SO332 (6.30 g/L).