Los hongos filamentosos: historia de un éxito biotecnológico: lección inaugural curso académico 2017-2018 Campus de Ponferrada

[ES] El planteamiento de una lección inaugural de un curso académico siempre debe tener un sentido generalista, dado el carácter multidisciplinar de la audiencia, pero a su vez suficientemente atractivo para suscitar el interés de la misma, evitando aspectos excesivamente técnicos y especializados. Por ello planteo esta lección, en su parte inicial, de forma semejante a como lo haríamos en lecciones de inicio de curso de alumnos que cursan asignaturas de microbiología por primera vez en sus carreras universitarias, como serían los alumnos de los actuales Grados en Biología, Biotecnología, Enfermería e Ingeniería Agroalimentaria, que son en las que he centrado mi labor docente de los últimos años. Para ello intentaré en un principio describir las características principales de los hongos filamentosos, su relación con el resto de los seres vivos, los distintos tipos de hongos existentes, su importancia en la naturaleza, así como sus aplicaciones en la industria biotecnológica, centrando la lección en los aspectos que han sido estudiados por los grupos de investigación en los que he estado implicado. Finalmente se analizará cual ha sido el impacto de las nuevas herramientas moleculares en el estudio de estos organismos

Performance assessment of a kinetically-powered network for herd localization

Developing a herd localization system capable to operate unattended in communication-challenged areas arises from the necessity of improving current systems in terms of cost, autonomy or any other facilities that a certain target group (or overall users) may demand. A network architecture of herd localization is proposed with its corresponding hardware and a methodology to assess performance in different operating conditions. The system is designed taking into account an eventual environmental impact hence most nodes are simple, cheap and kinetically powered from animal movements-neither batteries nor sophisticated processor chips are needed. Other network elements integrating GPS and batteries operate with selectable duty cycles, thus reducing maintenance duties. Equipment has been tested on Scandinavian reindeer in Lapland and its element modeling is integrated into a simulator to analyze such localization network applicability for different use cases. Performance indicators (detection frequency, localization accuracy and delay) are fitted to assess the overall performance; system relative costs are enclosed also for a range of deployments

La situación del narcotráfico en Colombia ad portas del posacuerdo

Este trabajo revisa las diferentes etapas de la cadena de valor del narcotráfico en Colombia, empezando por el cultivo de la hoja de coca, pasando por el microtráfico en ciudades del país y el lavado de las rentas provenientes de este negocio. Asimismo, revisa las implicaciones que sobre la cadena del narcotráfico tiene la firma de un acuerdo entre el Gobierno Nacional y las FARC. Esta revisión hizo evidentes dos retos principales de cara al posacuerdo: Primero, la lucha contra la cadena del narcotráfico se ha fundamentado en acciones dirigidas a los eslabones más fáciles de atacar, que a su vez son los menos valor agregado generan en el negocio. En particular, gran parte de los recursos se ha orientado a la reducción de cultivos ilícitos enfrentando campesinos cultivadores, con menos acciones dirigidas a la destrucción de laboratorios e interdicción, pocas al microtráfico y casi ninguna al lavado de activos. Esto tiene serias implicaciones sobre la legitimidad del Estado y sobre resultados tangibles que logren disminuir de manera significativa las rentas del tráfico de cocaína. Segundo, no es claro que el Gobierno Nacional tenga la capacidad de copar los espacios de control territorial que tienen hoy las FARC. Este grupo armado ilegal controla gran parte de los cultivos ilícitos de coca y pretende apoyarse en los cultivadores, entre otros, como base política en el posacuerdo. No obstante, es claro que otros grupos como el ELN y las bandas criminales tienen suficientes incentivos para, una vez las Farc estén por fuera del espectro político y se vean impedidas para obtener sus intereses por la fuerza, ampliar su control territorial sobre estas zonas. Una parte importante de las ganancias que trae el posacuerdo para el país dependerán de cómo se sortea esta situación. Este trabajo propone una revisión de estos retos, y contribuye a la discusión de política pública sobre las que se fundamentarán las instituciones del posacuerdo

Silencing of the Aspergillopepsin B (pepB) Gene of Aspergillus awamori by Antisense RNA Expression or Protease Removal by Gene Disruption Results in a Large Increase in Thaumatin Production

[EN] Aspergillopepsin B was identified in culture broths of Aspergillus awamori by in situ detection of its proteolytic activity and by immunodetection with anti-aspergillopepsin B antibodies. Severe thaumatin degradation was observed after in vitro treatment of thaumatin with purified aspergillopepsin B. The pepB gene encoding aspergillopepsin B of A. awamori was cloned and characterized. It is located in chromosome IV of A. awamori, as shown by pulsed-field gel electrophoresis, and encodes a protein of 282 amino acids with high similarity to the aspergillopepsin B of Aspergillus niger var. macrosporus. The pepB gene is expressed at high rates as a monocistronic 1.0-kb transcript in media with casein at acidic pH values. An antisense cassette constructed by inserting the pepB gene in the antisense orientation downstream from the gpdA promoter resulted in a good level of antisense mRNA, as shown by reverse transcription-PCR. Partial silencing of the pepB gene by the antisense mRNA resulted in a 31% increase in thaumatin yield. However, significant residual degradation of thaumatin still occurred. To completely remove aspergillopepsin B, the pepB gene was deleted by double crossover. Two of the selected transformants lacked the endogenous pepB gene and did not form aspergillopepsin B. Thaumatin yields increased by between 45% in transformant APB 7/25 and 125% in transformant 7/36 with respect to the parental strain. Reduction of proteolytic degradation by gene silencing with antisense mRNA or total removal of the aspergillopepsin B by directed gene deletion was a very useful method for improving thaumatin production in A. awamori.S

Targeted Inactivation of the mecB Gene, Encoding Cystathionine-γ-Lyase, Shows that the Reverse Transsulfuration Pathway Is Required for High-Level Cephalosporin Biosynthesis inAcremonium chrysogenum C10 but Not for Methionine Induction of the Cephalosporin Genes

[EN] Targeted gene disruption efficiency in Acremonium chrysogenum was increased 10-fold by applying the double-marker enrichment technique to this filamentous fungus. Disruption of themecB gene by the double-marker technique was achieved in 5% of the transformants screened. Mutants T6 and T24, obtained by gene replacement, showed an inactive mecB gene by Southern blot analysis and no cystathionine-γ-lyase activity. These mutants exhibited lower cephalosporin production than that of the control strain, A. chrysogenum C10, in MDFA medium supplemented with methionine. However, there was no difference in cephalosporin production between parental strain A. chrysogenum C10 and the mutants T6 and T24 in Shen's defined fermentation medium (MDFA) without methionine. These results indicate that the supply of cysteine through the transsulfuration pathway is required for high-level cephalosporin biosynthesis but not for low-level production of this antibiotic in methionine-unsupplemented medium. Therefore, cysteine for cephalosporin biosynthesis in A. chrysogenum derives from the autotrophic (SH2) and the reverse transsulfuration pathways. Levels of methionine induction of the cephalosporin biosynthesis gene pcbC were identical in the parental strain and the mecB mutants, indicating that the induction effect is not mediated by cystathionine-γ-lyase.SIThis work was supported by a grant of the CICYT (BIO97-0289-C02-01). We thank A. Paszewski for providing Aspergillus nidulansstrains M63 and C47 and M. Mediavilla, B. Martı́n, R. Barrientos, and M. Corrales for excellent technical assistance

Timber Specimens Parametrized Design for Numerical Analysis

[Abstract] The characterization of materials or the study of resistant response associated with new constructive solutions often convey progressive adjustment of models of analysis starting from the results obtained by means of test campaigns. The reliability of the conclusions will obviously be conditioned by the amplitude of the experimental development which, as a result, should contain a sufficiently representative sampling of cases. In the situations where significantly multiple parameters intervene, specimens that involve possible values and combinations should be examined, which in practice remarkably increases the number of specimens to be treated. The case being presented deals with the evaluation of the effectiveness of certain fixed joints carried out by gluing metallic bars into timber pieces by means of adhesives of different formulations. The set of calculus patterns, including the extensive variability of the associated magnitudes, has been treated in a parametrized form. The geometry of the studied pieces, as well as the sustenance conditions and the load, are automatically generated by means of software specially designed for those purposes. The resulting information is structured in an orderly way to facilitate its reading and also its manipulation if needed. The files of the process obtained in this way can optionally incorporate the meshing sequences, as well as the commands of the calculus, analysis and postprocess. The adopted strategy considerably reduces the time assigned to the phases of the geometrical definition and resolution, and enormously simplifies the interpretation of the results

De la crisis a la oportunidad: Internacionalización de la educación superior después de la COVID-19

Este artículo resalta algunos de los principales hallazgos de un estudio liderado por la Asociación Mexicana para la Educación Internacional (AMPEI) que logró documentar el sentir, pensar y actuar de diversos actores del ecosistema de internacionalización de la educación superior a lo largo del continente americano, frente a los retos de la “nueva normalidad”.  Se destaca cómo las asociaciones, redes y consorcios tienen un rol fundamental como constructores de puentes entre diversas instituciones (incluyendo sus grupos académicos), así como con otros actores como los gobiernos. Se ilustra, además, cómo con voluntad, creatividad, y un buen uso de las tecnologías de la información, las instituciones de educación superior pueden reinventar sus currículos y portafolios educativos con el fin de asegurar que la amplia mayoría de estudiantes desarrollen competencias globales e interculturales. Por último, se hace un llamado a no aspirar a un regreso a la “normalidad” prepandémica, sino a una “nueva normalidad” que se caracterice por su sensibilidad, humanidad y enfoque en la justicia social.   Palabras clave: Postpandemia; Internacionalización;  Asociaciones internacionales; Nueva normalidad

Volatile-mediated interactions between Trichoderma harzianum and Acanthoscelides obtectus: A novel in vitro methodology to evaluate the impact of microbial volatile compounds on dry grain storage pests

.Biological interactions mediated by Biogenic Volatile Organic Compounds (BVOCs) is a well-established field that has been researched for decades. Although extensive focus is currently given to the control of insect pests using natural molecules, the study of volatile interactions between microorganisms and insects has been largely neglected and has only begun to attract more attention in recent years. In this work, we developed a novel protocol to assess the effects of microbial BVOCs directly produced by growing microbial strains on dry grain insect pests and the seed damage they cause, using VOC Chambers to evaluate both sealed and unsealed conditions. Four Trichoderma harzianum strains were tested against Acanthoscelides obtectus, a wild type and three of its transformants. These had been previously obtained by introducing the tri5 gene and thus overproducing the volatile trichodiene, or by silencing the erg1 gene, which encodes for a squalene epoxidase, therefore reducing ergosterol levels and increasing squalene ones in the fungus. Results demonstrated that ventilation plays a key role in these interactions. All fungal strains significantly increased adult mortality in sealed conditions, while this effect was barely noticeable in unsealed ones. Nevertheless, subsequent insect emergence from bean seeds and bean damage were still significantly reduced in both conditions. The erg1 silenced strains caused significantly higher levels of adult mortality than the rest in sealed conditions and lower insect emergence in both sealed and unsealed ones. Bean damage produced by insects was lower also when exposed to BVOCs from these strains in sealed conditions. Conversely, trichodiene overproduction did not show enhanced toxicity or significant reduction of insect emergence and bean damage in the tested conditions. Therefore, T. harzianum BVOCs, especially those from erg1 silenced strains, should be further researched for their potential use in the biological control of A. obtectus infestation in dry grain storing facilities. VOC Chambers have shown themselves to be a reliable method in the screening of in vitro volatile mediated interactions between growing microbial strains and insect pests.S

Involvement of Trichoderma harzianum Epl-1 Protein in the Regulation of Botrytis Virulence- and Tomato Defense-Related Genes

[EN] Several Trichoderma spp. are well known for their ability to: (i) act as important biocontrol agents against phytopathogenic fungi; (ii) function as biofertilizers; (iii) increase the tolerance of plants to biotic and abiotic stresses; and (iv) induce plant defense responses via the production and secretion of elicitor molecules. In this study, we analyzed the gene-regulation effects of Trichoderma harzianum Epl-1 protein during the interactions of mutant ∆epl-1 or wild-type T. harzianum strains with: (a) the phytopathogen Botrytis cinerea and (b) with tomato plants, on short (24 h hydroponic cultures) and long periods (4-weeks old plants) after Trichoderma inoculation. Our results indicate that T. harzianum Epl-1 protein affects the in vitro expression of B. cinerea virulence genes, especially those involved in the botrydial biosynthesis (BcBOT genes), during the mycoparasitism interaction. The tomato defense-related genes were also affected, indicating that Epl-1 is involved in the elicitation of the salicylic acid pathway. Moreover, Epl-1 also regulates the priming effect in host tomato plants and contributes to enhance the interaction with the host tomato plant during the early stage of root colonizationSIThis work was supported by the State of São Paulo Research Foundation (FAPESP) (Proc. 2012/16895-4, Proc. 2013/24452-8, and Proc. 2016/04274-6). Funding was also obtained from the Junta de Castilla y León, Spain (LE228U14) and the Spanish Government Grants from Ministerio de Economía y Competitividad (AGL2012-40041-C02-02 and AGL2015-70671-C2-2-R