Vicente Peña-Caballero

A formal framework of bioprocesses enables accurate prediction of reaction outcomes, thereby optimizing resource allocation and reducing production costs. This study aimed to establish an approximate stoichiometric equation and determine the bioenergetics growth parameters of the pink oyster mushroom (Pleurotus djamor) using a “black box” modeling approach. A commercial strain was cultivated in polypropylene bags at 28 °C and 75% relative humidity. The harvested mushroom biomass was dried and analyzed for C, H, and N content, with O determined by difference. The resulting empirical formulas were CH_1.33O_0.36N_0.02 for the dry wheat straw substrate and CH_1.81O_0.41N_0.09 for the fungal biomass. The bioprocess exhibited a primordia initiation period of 20.5 days, a total harvest window of 50.0 days, a maximum biological efficiency of 16.77%, a model yield (Y) of 0.90%, and a productivity of 20.5 g/100 g substrate. In conclusion, this biotechnological framework provides a robust predictive tool for industrial scaling, enabling mass and energy balance optimization in real time without reliance on costly intracellular measurements. Thus, it establishes a reliable and sustainable pathway to convert low-cost agricultural residues into high-value bioproducts, supporting the goals of a circular economy.

Currently, microalgae cultivation requires strategies to improve yield and reduce production costs for biotechnological purposes. Dual-purpose systems are one of the most widely used strategies for these purposes, using culture media supplemented with wastewater. This study evaluated the growth of a microalgal consortium in three treatments with different proportions of dairy wastewater (WWDI) and synthetic BBM-3N medium (Bold Basal Medium), with the aim of optimizing biomass, chlorophyll, and lipid production. The treatment with 60% BBM-3N medium and 40% WWDI (Case 3) showed the best performance under experimental conditions, reaching a biomass concentration of 0.7543 g/L, a chlorophyll production of 10.6890 µg/mL, and a lipid content of 14.63%. These results exceeded those obtained in the cases with 100% BBM-3N or 100% WWDI. In addition, a techno-economic evaluation was carried out via SuperPro Designer simulation, which allowed the annual operating costs for each treatment to be estimated. Case 3 stood out as the most viable option, combining good biological performance with lower operating costs compared to the raw material, demonstrating the potential of using wastewater as a partial source of nutrients in microalgal cultures intended for the production of value-added products.

This paper presents a contrast of two different observation strategies viz a nonlinear observer and a classical extended Luenberger observer applied to a bioreactor system for Bacillus thuringiensis production. The performance of the two observers was evaluated under different conditions, both with and without state perturbations. Firstly, equal initial conditions were considered without the presence of white noise in the measurement of dissolved oxygen concentration in the culture medium. The performance was then analyzed by perturbing the maximum cell growth rate with equal and different initial conditions, and, finally, the performance of the observer with the presence of white noise was evaluated. The proposed observer performed better than the extended Luenberger observer against initial conditions different from the model. The results of this study are of great interest, as they provide insight into the estimation of the state of the dynamics for the B. thuringiensis bioreactor in a batch mode. In addition, these results provide valuable information for future research in the design of observers for B. thuringiensis bioprocessing.

Las microalgas cultivadas en fotobiorreactores (FBR) se utilizan para producir biocombustibles renovables (biodiésel, bioetanol, biogás y biohidrógeno) por su capacidad de poder producir 20-50% lípidos del peso seco de la biomasa, además para producir bienes y diseño de servicios. El modelado del FBR mediante el modelo Droop, o Droop Model, se ha utilizado para describir la dinámica y la limitación de sustratos en este bioproceso. Así, muchos procesos de producción de microalgas en FBR están normalmente controlados mediante controladores clásicos todo/nada sin considerar el modelo sistema. Debido a la importancia de mantener el/los sustrato(s) dentro de valores determinados para maximizar la productividad, en este estudio, abordamos el problema de regulación de la concentración de sustrato en el FBR mediante la implementación numérica de un nuevo controlador no lineal en la dinámica de un FTB basado el modelo Droop. La respuesta de la dinámica no lineal del sistema a lazo abierto ante diferentes tasas de dilución (D=0.5,1.0,1.5 ,2.0 1/d) fue estable y controlable y la influencia del parámetro cinético K_q en las concentraciones biomasa, quota y sustrato en el FBR fueron más sensible a diferencia de los parámetros cinéticos ρ_m, K_m, μ_m en el modelo de Droop. El controlador propuesto se compara con un controlador clásico Proporcional-Integral PI. Los resultados del desempeño de los controladores fueron evaluados numéricamente mediante el índice de desempeño ITSE frente a diferentes perturbaciones. Como resultado, se encuentra que el controlador propuesto presento un mejor desempeño para diferentes cambios de los valores de referencia de la concentración de sustrato.

Agricultural and agro-industrial waste are good adsorbents of heavy metals, whether used naturally, pretreated or immobilized in other biopolymers, due to their content of functional groups with positive and/or negative charges. In addition, they are characterized for being biodegradable and for their compatibility with other materials, and for their opportunity of reuse for the design of alternative technologies for the treatment of water contaminated with heavy metals, for example: cadmium (Cd), chromium (Cr), lead (Pb), among other metals, with negative impact on society and the environment. In this sense, the objective of the present work was to evaluate the adsorption capacity of hexavalent chromium, Cr(VI), by using three organic adsorbent materials (derived from residual materials from the production of Pleurotus djamor) and immobilized on alginate in continuous adsorption processes to evaluate the adsorption capacity of Cr(VI) on the adsorbents. For this purpose, the adsorption capacity of chromium ions in aqueous phase in a glass tank (glass reactor) with a controllable stirring system was evaluated, as well as the rate of Cr(VI) increase and the adsorption load of the metal on the adsorbents. The results show a better adsorption capacity on the adsorbent composed of depleted wheat substrate and immobilized on sodium alginate. In relation to the lowest Cr(VI) rate of increase in the tank volume, it was 0.1251 and 0.0072 mg Cr(VI) min-1, respectively, 60 and 5 mg L-1 of Cr(VI) in the feed stream to the tank. Both results for depleted and immobilized substrate in sodium alginate. Finally, for the same adsorbent, the adsorbent loading capacity was higher. The adsorbents preliminarily analyzed showed good adsorption capacity.

This study deals with the problem of estimating the amount of biomass and lactic acid concentration in a lactic acid production process. A continuous stirred tank bioreactor was used for the culture of Lactobacillus helveticus . A nonlinear sliding mode observer is proposed and designed, which gives an estimate of both the biomass and lactic acid concentrations as a function of glucose uptake from the culture medium. Numerical results are given to illustrate the effectiveness of the proposed observer against a standard sliding-mode observer. It was found that the proposed observer worked very well for the benchmark bioreactor model. Also, the numerical results indicated that the proposed estimation methodology was robust to the uncertainties associated with un-modelled dynamics. These new sensing technologies, when coupled to software models, improve performance for smart process control, monitoring, and prediction.

Distribution, eco-climatic characterisation, and potential growing regions of Annona cherimola Mill. (Annonaceae) in Mexico.