In this study, genetic programming (GP) was the systematic method used to identify the structure and parameters of a mathematical model for ethanol fermentation. The mathematical model simulated the effect of temperature on the kinetics of batch ethanol fermentation and helped to find out the optimum temperature for the better performance of the process. Saccharomyces cerevisiae CSI-1 growing in cane molasses-based media was the microorganism used in all the experiments. Achieving the model’s precision in describing the experimental observations involved the estimation of its structure (non-linear principally) and its constant parameters. The model found describes the fermentation kinetics and showed a fair prediction for Dry cell weight (DCW), Colony forming units/mL (CFU/mL), Residual sucrose (RS), Residual glucose (RG) and Ethanol concentration (E). The model was used to optimize the operating conditions of the process. The predictions from the model in terms of Mean Square Error (MSE) and Sum Squared Error (SSE) fitted the experimental data well with fitness values in a range of R2 ? 0:92.

The devil fish (Hypostomus plecostomus) is a highly invasive exotic species due to its remarkable adaptability and the significant ecological damage it causes in aquatic ecosystems. This research aimed to extract, characterize, and evaluate the chemical purification of chitosan from fish tegumental shields, comparing it with chitosan obtained from shrimp exoskeletons. The biopolymer was purified through acid-alkaline hydrolysis (0.6 M HCl/25°C/1h and 0.4 M NaOH/28°C/3h), deacetylation (40% NaOH/110°C/5.5h), and depigmentation (38% NaClO/28°C/0.15h). Desmineralization, deproteinization, color chart, insoluble content, degree of acetylation, molecular weight, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were evaluated. Chitosans from shrimp exoskeletons and devil fish tegumental shields obtained deproteinization percentages of 98.91 and 97.67%, desmineralization of 98.19 and 97.95%, deacetylation percentages of 82.031 and 83.346%, and molecular weights (MW) of 112.934 and 206.507 kDa respectively. FT-IR results identified an absorption band corresponding to C=O stretching in both samples, indicating the presence of carboxylic anion (-COO). Thermograms showed lower degradation temperatures (308°C) for commercial chitosan compared to that from devil fish (324°C). Devil fish tegumental shields offer chitosan similar to commercial sources, with significant economic potential and a 25% yield, potentially controlling invasive populations and restoring ecosystems.