Bacterial cellulose (BC) is emerging as an attractive large-scale polymer due to its superior properties. The dominant static culture for BC fermentation by bacteria or microbial consortium results in low productivity. Agitated culture, as an industrially projected technique, has been widely investigated but exclusively for cellulose-producing bacterial strains. Addressing this concern and evaluating the potential of residues as feedstock, this study highlights the utilization of microbial consortium BA2 and seven agro-industrial wastes including cocoa husks, sugarcane bagasse and others. Remarkably, rice bran (RB) appears as a promising substrate, achieving 2.14 g/L (dry basis) and outperforming the traditional HS medium, evident from a 15-day fermentation. A complex interplay between oxygen availability, glucose consumption and BC yield was revealed; while orbital and magnetic stirring with forced air ventilation (AFV) showed low BC yields and early biomass saturation, 4.07 g/L (dry basis) was targeted by magnetic stirring at 100 rpm from the start using only headspace air. However, beyond controlled operating conditions, mechanical agitation and favorable cellulose adhesion to metal in the stirred tank bioreactor negatively affect BC yield. This pattern uncovers the need for a further approach to the design of bioreactors when the microbial consortium is considered.

This work describes an efficient and environmentally friendly method for the synthesis of silver-based nanostructures through a green route using Aloe vera extract as a reducing agent, silver nitrate (AgNO₃) as a precursor, and polyvinylpyrrolidone (PVP, 10 kDa molecular weight) as a stabilizing agent. The formation of these structures was supported by UV–Vis spectroscopy, where a surface plasmon resonance (SPR) band was observed between 425 and 460 nm. Scanning electron microscopy revealed predominantly spherical features in the 300–500 nm range; however, the distinction between primary nanoparticles and aggregates cannot be conclusively established from SEM alone. EDX analysis indicated a silver content of 59.96 wt%. Antibacterial assays performed in Z8 medium demonstrated a reduction in cyanobacterial growth with increasing dosage, with complete inhibition observed at ≥20 $\mu$L (nominal MIC = 1.77 mg mL⁻¹, based on precursor estimation). Total dissolved solids and absorbance measurements exhibited a decreasing trend with increasing concentration (effect size = 0.87, $p<0.001$), supporting an inhibitory effect under the tested conditions. These findings suggest potential antibacterial activity. However, this study should be considered exploratory, and further work is required to elucidate the underlying mechanisms.

This work presents the design of an agitation system for a 1m3 capacity bioreactor intended to produce glyceric acid (GA) through microbial fermentation of A. tropicalis using 20% v/v glycerol as the primary substrate. Building on previous studies that evaluated ideal conditions for glyceric acid production, initial data were utilized to identify the impeller type and perform subsequent calculations, including impeller Reynolds number, power consumption, and mixing time. Once the agitator type was specified, standard geometric relationships were employed to size components of the agitation system, such as tank size, baffle plates, and agitator dimensions. Power consumption calculations were compared with results from other studies on fermentation media with similar rheological characteristics. The agitator's power consumption for mixing 1m3 of medium was determined to be 8.35 kW, achieving 95% homogenization in 5.14 seconds, with a mixing time error of approximately 10%, operating at an agitation speed of 500 rpm.

In the present manuscript, the effect of temperature on crystallisation of perovskite thin films (CH3NH3PbI3-xClx) was analysed (perovskite films are utilized to produce perovskite-based solar cells that appear to be devices with lower production costs and higher efficiency than silicon-based solar cells). To synthesise the perovskite films, four samples with precursor solution were spin coated for 45 s at 2000 rpm. After that, the samples were annealed at three different temperatures. Likewise, samples were characterised by UV/Vis Spectroscopy, Emission Spectroscopy, Fluorescence Microscopy, and ImageJ software were used to analyse crystal size. It was found that the sample annealed at 80 oC presented the highest fluorescence emission with 49539.09 CPS and the best particle size distribution. Band Gap Energy (Eg) was also calculated resulting in 1.60 ± 0.01 eV (An ideal solar cell has a band gap of 1.4 eV to absorb the maximum number of photons from the solar radiation).

En la ingeniería de procesos, el estudio de la transformación de la materia a través de operaciones específicas permite la elaboración de productos de origen biotecnológico con un interés social novedoso. Por ello, el principal objetivo de esta investigación fue diseñar un proceso para la producción de cerveza con cannabidiol a escala piloto. El desarrollo metódico subsecuente se basó en la elaboración de un lote de 5 litros a escala de laboratorio, en donde se recopilaron datos mediante balances de materia y energía. Se escaló el proceso y se diseñó el diagrama de bloques y de flujo de proceso (BFD y PFD), además de una caracterización fisicoquímica y microbiológica del producto. Los resultados permitieron comprender las condiciones de operación del biorreactor, determinando el pH y temperatura óptimos. También, la caracterización fisicoquímica y microbiológica mostró valores normales según las normas INEN y AOAC de elaboración de cerveza, con excepción de la acidez total y mesófilos aerobios. Se evidenciaron las características y propiedades de la cerveza deseada al final del proceso, a la par de una correcta estructuración del proceso por medio de los datos obtenidos.