The cob is the residue generated from the separation of the grain from the cob, and due to its components, it is considered a lignocellulosic material, so its use is limited, which favors the burning of the cob and its spreading, thus generating a problem of environmental pollution. Probiotics are live microorganisms that, when supplied in adequate amounts, provide a beneficial effect to the host, reducing the carbohydrate content in lignocellulosic materials through fermentation, obtaining a product rich in nutrients. Therefore, this research aimed to determine the kinetic parameters of biotransformation of corn residues through the fermentative action of the probiotic bacteria Lactobacillus acidophilus. Anaerobic fermentation kinetics were performed using the bacterium Lactobacillus acidophilus at different concentrations (10 and 15% v/v) to obtain kinetic parameters of microbial growth and substrate consumption for the biotransformation of white corn (Zea MaysL.) residues. The kinetic parameters indicate that when using 15% inoculum, the bacteria adapt to a greater extent to the substrate since the Ks value was 0.5693 g/L and the adaptation time was 18.25 h, thus allowing the growth of Lactobacillus acidophilus and therefore the process of biotransformation of corn residues. While for the consumption of substrate, it was identified that the use of 10% inoculum was better since it presented a value of k of 0.2534 that is higher than the value obtained when 15% is used because the rate of substrate consumption is faster. Therefore, the dose of 15% inoculum seems to be the most suitable for the adaptation of the bacteria in the shortest time and therefore the biotransformation process is carried out.

Increases in poultry industry production have resulted in the generation of more hazardous effluents with high nitrogen and chemical oxygen demand (COD) concentrations. It is necessary to develop more efficient technologies in terms of water purification without the need to increase the volumes of commonly used reactors. This work analyzed the addition of micronutrients (Mo, Zn, Cu, and Mn) for the cultivation of the microalgae Chlorella spp. and Spirulina maxima in poultry wastewater. The effects of micronutrients on the production of biomass and algal cells were also assessed. For the Chlorella species, removal efficiencies of up to 99.14% for COD and 99.33% for nitrogen were achieved; for the Spirulina strain, these efficiencies were 98% for COD and 99% for nitrogen. The modified Gompertz equation was used to analyze the kinetic parameters. For both microalgae, the R² values were greater than 98%. The results indicated that the dose with the highest algal cell generation rate was dose 2 for Chlorella spp., at 4.35 days, and dose 1 for Spirulina maxima, at 6.26 days. Microalgae are biological alternatives suitable for wastewater treatment, and their pollutant removal efficiency can increase with the addition of micronutrients, which has additional benefits for the production of valuable biomasses for industrial applications.

The growing demand for chicken meat products has increased the amount of wastewater associated with their production; their treatment has increased the generation of sludge and oils trapped in the trap process treatment. This work presents a process for the valorization of this residual oil recovered through the production of biodiesel. An oil degumming process was applied, and the quality of the treated oil was evaluated. This was transesterified with alkaline conditions and a homogeneous catalyst (KOH); a 3^k experimental design was applied with two factors: the temperature at 50, 60, and 70 °C and the molar ratios of 5, 6, and 7 moles of methanol per mole of recovered chicken oil. The biodiesel quality parameters were evaluated based on the ASTM standard. The process achieved a yield of 90.2%. The biodiesel obtained met all the quality parameters; however, only the process conditions with a molar ratio of 6:1 and a temperature of 60 °C achieved a kinematic viscosity of 5.64 ± 0.15 mm² s⁻¹, meeting the limits of 1.9–6.0 mm² s⁻¹ of the ASTM regulation. The fluidity of this biodiesel in mixtures of 25, 50, and 75% v with petroleum diesel was also evaluated, and a better adjustment of the Bingham mixing rule model and rheological analysis revealed that the mixtures did not lose their Newtonian behavior. This allows for the application of this biodiesel in internal combustion engines, achieving the valorization of residual oil.