In this study, a mathematical model was proposed for a continuous, multistage, industrial-scale alcoholic fermentation process, comprising four vats in series with volumes equal to 600 m³, with separation, acid treatment, and cell recycling from the fourth to the first vat. The system was operated daily under variable volumetric flow rates and substrate concentrations in the feed stream, i.e., F₀ = 93–127 m³/h and S₀ = 210–238 g/L. The mathematical model consisted of mass balance equations for cells, substrate, and product in the vats, the separator, and the acid treatment unit. An unsegregated and unstructured approach was used to describe the microbial population, with the kinetics of cell growth, substrate consumption, and product formation represented by equations generally adopted for alcoholic fermentation. The model parameters were estimated by nonlinear regression, providing typical values for alcoholic fermentation. Model predictions agreed well with both the experimental data used in the parameter estimation step and those used in the model validation step.

Natural colorants derived from filamentous fungi have gained increasing attention as safe, sustainable, and bioactive alternatives to synthetic counterparts. This study evaluated the red colorant production by Talaromyces sp. under solid and static submerged culture conditions, focusing on the selection of carbon and nitrogen sources and the influence of the inoculum’s physiological state. In solid-state cultivation, oat-based medium and Potato Dextrose Agar (PDA) supplemented with glycine (PDAG) promoted intense sporulation and red–yellow pigmentation, whereas sugar-rich media, specifically Yeast Extract Sucrose (YES) and Sabouraud Agar, led to rapid mycelial growth but reduced sporulation. Radial growth rates ranged from 0.295 to 0.391 cm/day, depending on the growth medium. YES medium supported the fastest growth; however, it was ineffective in promoting colorant induction when used as an inoculum source for liquid culture. Under static submerged fermentation conditions, inoculum derived from PDAG and PDA supplemented with yeast extract (PDA + YE) produced the highest colorant titers, highlighting that the inoculum developmental stage is a key determinant in activating azaphilone colorant biosynthesis. Additionally, commercial sucrose and sugarcane juice were identified as the most effective carbon sources, outperforming lignocellulosic hydrolysates from sugarcane bagasse, rice, and corn. A preliminary economic analysis estimated production costs ranging from US$ 3.11 to US$ 3.34 per liter of colorant. A Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis revealed key strengths such as high colorant productivity, alongside significant opportunities in the natural ingredients market. Overall, these findings underscore the technical and economic potential of Talaromyces-based biocolorant production, positioning it as a sustainable and competitive alternative to synthetic colorants.