Optimización de la metodología para la producción de hongos comestibles

El cultivo de hongos comestibles saprófitos constituye un sistema de producción-consumo, que ha adquirido gran relevancia social, económica y ecológica. Con el fin de abaratar costes a la vez que aprovechar y reciclar residuos forestales, el objetivo de este trabajo se ha centrado en evaluar la viabilidad del aserrín de Eucalyptus globulus como soporte del cultivo en bolsa de Lentinula edodes (hongo comercializado conocido como Shiitake) y Agrocybe aegerita (hongo no comercializado comúnmente llamado Seta de Chopo). Se han evaluado 6 formulaciones, todas ellas con el aserrín como componente principal y con adición de diferentes suplementos: cereales (salvado y mijo), un controlador del pH (CaCO3) y un estimulador de crecimiento (CaSO4). Se ha determinado el crecimiento miceliar sobre cada uno de los sustratos, así como la producción de carpoforos (tanto en cantidad como en calidad) y la duración del periodo de fructificación. La mezcla más efectiva para la producción de L. edodes fue aquella que contenía yeso y azúcar mientras que para A. aegerita el salvado resultó ser el mejor suplemento.

Magnetic Cross-Linked Enzyme Aggregates (mCLEAs) of Candida antarctica Lipase: An Efficient and Stable Biocatalyst for Biodiesel Synthesis

Enzyme-catalyzed production of biodiesel is the object of extensive research due to the global shortage of fossil fuels and increased environmental concerns. Herein we report the preparation and main characteristics of a novel biocatalyst consisting of Cross-Linked Enzyme Aggregates (CLEAs) of Candida antarctica lipase B (CALB) which are covalently bound to magnetic nanoparticles, and tackle its use for the synthesis of biodiesel from non-edible vegetable and waste frying oils. For this purpose, insolubilized CALB was covalently cross-linked to magnetic nanoparticles of magnetite which the surface was functionalized with –NH2 groups. The resulting biocatalyst combines the relevant catalytic properties of CLEAs (as great stability and feasibility for their reutilization) and the magnetic character, and thus the final product (mCLEAs) are superparamagnetic particles of a robust catalyst which is more stable than the free enzyme, easily recoverable from the reaction medium and reusable for new catalytic cycles. We have studied the main properties of this biocatalyst and we have assessed its utility to catalyze transesterification reactions to obtain biodiesel from non-edible vegetable oils including unrefined soybean, jatropha and cameline, as well as waste frying oil. Using 1% mCLEAs (w/w of oil) conversions near 80% were routinely obtained at 30°C after 24 h of reaction, this value rising to 92% after 72 h. Moreover, the magnetic biocatalyst can be easily recovered from the reaction mixture and reused for at least ten consecutive cycles of 24 h without apparent loss of activity. The obtained results suggest that mCLEAs prepared from CALB can become a powerful biocatalyst for application at industrial scale with better performance than those currently available.