Sustainable Ethanol Production From Sugarcane Molasses by Saccharomyces cerevisiae Immobilized on Chitosan-Coated Manganese Ferrite

The interaction between nanostructures and yeast cells, as well as the description of the effect of nanoparticles in ethanol production are open questions in the development of this nanobiotechnological process. The objective of the present study was to evaluate the ethanol production by Saccharomyces cerevisiae in the free and immobilized state on chitosan-coated manganese ferrite, using cane molasses as a carbon source. To obtain the chitosan-coated manganese ferrite, the one-step coprecipitation method was used. The nanoparticles were characterized by X-ray diffraction obtaining the typical diffraction pattern. The crystal size was calculated by the Scherrer equation as 15.2 nm. The kinetics of sugar consumption and ethanol production were evaluated by HPLC. With the immobilized system, it was possible to obtain an ethanol concentration of 56.15 g/L, as well as the total sugar consumption at 24 h of fermentation. Productivity and yield in this case were 2.3 ± 0.2 g/(L * h) and 0.28 ± 0.03, respectively. However, at the same time in the fermentation with free yeast, 39.1 g/L were obtained. The total consumption of fermentable sugar was observed only after 42 h, reaching an ethanol titer of 50.7 ± 3.1, productivity and yield of 1.4 ± 0.3 g/(L * h) and 0.25 ± 0.4, respectively. Therefore, a reduction in fermentation time, higher ethanol titer and productivity were demonstrated in the presence of nanoparticles. The application of manganese ferrite nanoparticles shows a beneficial effect on ethanol production. Research focused on the task of defining the mechanism of their action and evaluation of the reuse of biomass immobilized on manganese ferrite in the ethanol production process should be carried out in the future

Microencapsulación de componentes bioactivos

Microencapsulation is the process of covering an active substance with a porous wall, obtaining capsules between 50 nm to 2 mm. Different biologically active materials as enzymes, microorganisms, vitamins, hormones, among others, can be microencapsulated to protect them against environmental conditions. There are different microencapsulation methods, so the choice is based on the physical and chemical properties needed for the application and the production costs. This article discusses the advances in the area of microencapsulation focused on the properties of systems and some examples of its application, advantages and disadvantages.La microencapsulación es el proceso con el cual se rodea una sustancia activa con una pared porosa y se obtienen cápsulas de 50 nm a 2 mm. Diferentes materiales biológicamente activos como enzimas, microorganismos, vitaminas, hormonas, entre otros, pueden ser microencapsulados para protegerlos contra condiciones medioambientales. Existen diferentes métodos de microencapsulación, por lo que la elección de alguno se basa en las propiedades físicas y químicas que se requieran para su aplicación y los costos de producción. En el presente artículo se analizan los avances en el área de microencapsulación enfocados a las propiedades de los sistemas, algunos ejemplos de su aplicación y ventajas y desventajas

Purification and biochemical characterization of an Aspergillus niger phytase produced by solid-state fermentation using triticale residues as substrate

In this study, an extracellular phytase produced by Aspergillus niger 7A-1, was biochemically characterized for possible industrial application. The enzyme was purified from a crude extract obtained by solid-state fermentation (SSF) of triticale waste. The extract was obtained by microfiltration, ultrafiltration (300, 100 and 30 kDa) and DEAE-Sepharose column chromatography. The molecular weight of the purified enzyme was estimated to be 89 kDa by SDS-PAGE. The purified enzyme was most active at pH 5.3 and 56 °C, and retained 50% activity over a wide pH range of 4 to 7. The enzymatic thermostability assay showed that the enzyme retained more than 70% activity at 80 °C for 60 s, 40% activity for 120 s and 9% after 300 s. The phytase showed broad substrate specificity, a Km value of 220 μM and Vmax of 25 μM/min. The purified phytase retained 50% of its activity with phosphorylated compounds such as phenyl phosphate, 1-Naphthyl phosphate, 2-Naphthyl phosphate, p-Nitrophenyl phosphate and Glycerol-2-phosphate. The inhibition of phytase activity by metal ions was observed to be drastically inhibited (50%) by Ca++ and was slightly inhibited (10%) by Ni++, K+, and Na+, at 10 and 20 mM concentrations. A positive effect was obtained with Mg++, Mn++, Cu++, Cd++ and Ba++ at 25 and 35% with stimulatory effect on the phytase activity