Carmina Montiel

The genus Fusarium comprises several plant pathogenic species, some of which are etiological agents of vascular wilt in agave plants, inducing systemic necrosis across the roots, caudex (cone), and foliar tissues. Such disease compromises host vigor and biomass productivity, ultimately reducing the organoleptic quality of fermented and distilled derivatives, including mezcal, tequila, and other distillates. Thus, as part of our ongoing bioprospecting efforts in unexplored areas of Mexico, the chemical study of the organic extract from a solid-state fermentation culture of the manglicolous endophyte fungus Talaromyces islandicus M31, isolated in the Punta Sur Ecological Park in Cozumel Island Biosphere Reserve, Mexico, led to the separation of eight anthraquinone derivatives active against the agave pathogens Fusarium incarnatum (CRT-153 and CRT-197), Fusarium proliferatum (CRT-142), and Fusarium oxysporum (CRT-098 and CRT-214). Among the molecules tested, the bisdihydroanthraquinone (–)-luteoskyrin (6) exhibited the strongest growth-inhibitory activity, which was also measured over a two-month span. Through macromolecule leakage assay and scanning electron microscopy, we found that (–)-luteoskyrin (6) disrupted membrane integrity in F. incarnatum. Furthermore, a simple formulation consisting of inactivated T. islandicus M31 mycelium was tested in vivo to control Fusarium infection in agave. The results suggest that (–)-luteoskyrin (6) acts synergistically with other components, resulting in remarkable anti-Fusarium activity and demonstrating its efficacy and advantages for pest management.

La tecnología enzimática se ha convertido en un componente fundamental en el vasto panorama de la Biotecnología, particularmente (desde tiempos inmemoriales), en la industria de alimentos; sin dejar de lado a otras industrias como la de los detergentes o la textil, entre otras. En la actualidad, las enzimas destacan como herramientas versátiles capaces de catalizar reacciones químicas clave de manera específica y altamente eficiente, en la búsqueda constante de soluciones más eficientes, sostenibles y amigables con el medio ambiente. En esta era de creciente conciencia ambiental y demandas de eficiencia, explorar y comprender la tecnología enzimática se convierte en una necesidad. Esta obra emprende un viaje que explora diversos aspectos de esta tecnología fascinante, con un enfoque particular en su aplicación en áreas de la ciencia y la industria.

The study involves the use of commercial cellulase Cellic CTec2 in combination with two in-house xylanases, PxXyn10A (XynA), a recombinant purified enzyme from Paenibacillus xylanivorans A59, and a xylanase enzymatic extract from native Moesziomyces aphidis PYCC 5535T (MaPYCC 5535T), for the enzymatic hydrolysis of pretreated blue agave bagasse (BAB) at the high solids load of 20% (w/v). Three different combinations of cellulase and xylanases were evaluated. When Cellic^® CTec2 was used at a dosage of 10 FPU/g oven-dried solids (ODS) supplemented with XynA or MaPYCC 5535T at an endo-xylanase dosage of 100 U/g ODS, increases in the xylose yield of 30% and 33%, respectively, were obtained. When applying in-house xylanases alone (at an endo-xylanase dosage of 100 U/g ODS), xylan in BAB was selectively hydrolyzed into xylose with 5% yield with MaPYCC 5535T, while no xylose was detected with XynA. Interestingly, a synergic effect of Cellic^® CTec 2 with both xylanases was observed when using a low dosage of 1 FPU/g ODS (allowing for some liquefaction of the reaction mixture), promoting xylose and glucose release by either xylanase. A higher concentration of monomeric sugars was obtained with 10 FPU/g ODS of Cellic^® Ctec 2 supplemented with 100 U/g ODS of MaPYCC 5535T, followed by XynA. The improvement in saccharification through the synergistic combination of in-house xylanases and commercial cellulases allows for the obtention of sugar-rich hydrolysates, which enhances the technical sustainability of the process. Hydrolysates were then fermented using recombinant Cellux 4^TM yeast to yield 45 g/L ethanol, representing an increase of about 30% with respect to the control obtained with only the commercial cellulase cocktail. The surface modification of agave biomass with the different combinations of enzymes was evidenced by scanning electron microscopy (SEM).

Inulin is a fructose-based polysaccharide that can be found in several plant species, from grass and onions to chicory roots; thus, it has the potential to be an excellent renewable source of fructose for several industrial applications. Among them, inulin hydrolysis can be coupled to a fermentation operation to produce polyhydroxybutyrate (PHB) using Cupriavidusnecator H16. This work reports the PHB production process involving chicory root inulin hydrolysis using inulinase Novozym 960 followed by a C.necator fermentation. It was found that the maximum saccharification (95% wt.) was reached at 269 U/g_inulin after 90 min. The hydrolysates obtained were then inoculated with C.necator, leading to a biomass concentration of 4 g/L with 30% (w/w) polymer accumulation. Although PHB production was low, during the first hours, the cell growth and polymer accumulation detected did not coincide with a fructose concentration decrease, suggesting a simultaneous saccharification and fermentation process, potentially alleviating the product inhibition inherent to the inulinase–fructose system. The characterization of the obtained PHB showed a polymer with more homogeneous values of M_w, and better thermal stability than PHB produced using pure fructose as a fermentation substrate. The results obtained demonstrate a viable alternative carbon substrate for PHB production, opening the possibility for inulin-rich renewable feedstock valorization.

Virus-like particles (VLPs) comprise one or many structural components of virions, except their genetic material. Thus, VLPs keep their structural properties of cellular recognition while being non-infectious. VLPs of Parvovirus B19 (B19V) can be produced by the heterologous expression of their structural proteins VP1 and VP2 in bacteria. These proteins are purified under denaturing conditions, refolded, and assembled into VLPs. Moreover, chimeric forms of VP2 have been constructed to harbor peptides or functional proteins on the surface of the particles without dropping their competence to form VLPs, serving as presenting nanoparticles. The in-vitro assembly approach offers exciting possibilities for the composition of VLPs, as more than one chimeric form of VP2 can be included in the assembly stage, producing multifunctional VLPs. Here, the heterologous expression and in-vitro assembly of B19V structural proteins and their chimeras are reviewed. Considerations for the engineering of the structural proteins of B19V are also discussed. Finally, the construction of multifunctional VLPs and their future potential as innovative medical tools are examined.