Medium design from corncob hydrolyzate for pigment production by Talaromyces atroroseus GH2: Kinetics modeling and pigments characterization

The genus Talaromyces has gained attention due to its ability to produce pigments with potential industrial applications in different areas. Prosperous application of fungal pigments has challenges to overcome, like developing a cost-effective bioprocess. Using agroindustrial wastes could provide inexpensive substrates and it contributes to maximize sustainability. Therefore, this study evaluated the feasibility of using corncob as a low-cost substrate for pigment production by Talaromyces atroroseus GH2. An acid hydrolysis treatment was used to release sugars from corncob. Corncob liquors with enough xylose concentration (>20 g/L) were investigated as fermentation media with and without the addition of nutrients. Process kinetic modeling was applied and pigments produced in corncob and control media were characterized. The diluted hydrolyzate without nutrient supplementation showed a pigment production (16.17±0.37 OD_500nm) comparable to the control medium (17.26±0.41 OD_500nm). Talaromyces atroroseus GH2 was able to co-utilize xylose and glucose in the corncob-based medium. However, growth kinetics patterns differed in both media. In the hydrolyzate medium, biomass growth presented an extended lag phase, which requires reduction for future process optimization. Finally, characterized pigments differed among evaluated media, but the pigments produced by Talaromyces atroroseus GH2 were mostly Monascus’ pigments homologous like monascorubrin and rubropunctamine. Talaromyces atroroseus GH2 ability to produce pigments using corncob hydrolyzate makes it a pigment-producing strain for an economically competitive large fermentation scale.