Person:
Alonso Conde, Rafael Alejandro

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First Name
Rafael Alejandro
Last Name
Alonso Conde
Affiliation
Universidad Complutense de Madrid
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Now showing 1 - 9 of 9
  • Publication
    Enfermedades de la madera de la vid y su relación con la microbiota edáfica asociada a viñedos ecológicos singulares
    (Universidad Complutense de Madrid, 2021-05-31) Alonso Conde, Rafael Alejandro; Marquina Díaz, Domingo; Gómez Flechoso, María de los Ángeles
    El suelo se define como la parte más externa de la corteza terrestre y presenta un sistema de interacción entre tres fases bien definidas: una fase sólida, constituida por materia mineral y orgánica, una fase líquida y una fase gaseosa o atmósfera del suelo. La porción inorgánica es importante por su influencia en la disponibilidad de nutrientes, aireación y retención de agua. La materia orgánica que compone el suelo procede de la actividad de los distintos organismos vivos del suelo. El resto del volumen del suelo está constituido por espacios porosos, que a su vez están ocupados por agua y los gases que constituyen la atmósfera edáfica. Las interacciones que ocurren en el suelo vienen dadas por factores abióticos y bióticos. Entre los parámetros bióticos se encuentran; La capacidad de retención de agua en el suelo disponible para la planta, determinada mediante los parámetros Capacidad de Campo (CC) y Punto de Marchitez Permanente (PMP); Las variaciones de pH producidas por la actividad microbiana y la composición geoquímica del sustrato; Y la composición mineralógica del suelo, la cual se conecta estrechamente con los dos parámetros anteriores. Los parámetros bióticos que determinan la funcionalidad del suelo se miden de forma indirecta o directa. Una forma indirecta de inferir en la actividad microbiana del suelo es a través de la respiración (SIR) de los microorganismos que habitan en él. También el análisis de la actividad enzimática (β-galactosidasa, reductasa, fosfatasa y proteasa) de la población microbiana del suelo indica la fertilidad del mismo. Para analizar de forma directa las poblaciones microbianas que se encuentran en el suelo se utilizan recuentos de microorganismos viables mediante técnicas clásicas de microbiología y análisis meta-taxonómicos...
  • Publication
    Advances in the control of the spoilage caused by Zygosaccharomyces species on sweet wines and concentrated grape musts
    (Elsevier, 2015) Alonso Conde, Rafael Alejandro; Belda Aguilar, Ignacio; Santos de la Sen, Antonio; Navascués, Eva; Marquina Díaz, Domingo
    Zygosaccharomyces is one of the most damaging foodborne spoilage yeast, and tools for controlling its growth are limited due to its reported resistance to preservatives and osmotic stress. Zygosaccharomyces contamination may result in spoilage of grape juice concentrates or in re-fermentation and CO2 production in sweet wines so, biological control of these yeasts could be important. In this study, thirty-four strains belonging to Zygosaccharomyces have been identified and tested against a panel of eighteen killer yeasts. Here, for the first time, PMKT is proven to be effective against different strains of Zygosaccharomyces. Cultures in media composed by sweet wine and concentrated grape juice showed that PMKT has the ability to inhibit Zygosaccharomyces, while Saccharomyces cerevisiae was fully resistant in such conditions indicating that PMKT could be used to avoid the Zygosaccharomyces spoilage. Additionally, PMKT activity was determined in the presence of potassium sorbate and potassium metabisulphite showing unexpected synergistic effects with the latter, and making possible the promising application of reducing preservative concentrations in beverages.
  • Publication
    Specific and sensitive PCR detection of Cadophora luteo-olivacea associated with grapevine trunk diseases
    (Elsevier, 2020-03-11) Vicente Sánchez, Javier; Alonso Conde, Rafael Alejandro; Navascués, Eva; Marquina Díaz, Domingo; Santos de la Sen, Antonio
    Grapevine trunk diseases, caused by different fungal pathogens, are the most relevant group of diseases that affect vineyards, causing important economic losses. Quality control for sanitary purposes should be applied for different diseases in every stages of the plant development, from the nursery during propagation to the vineyard during grape production. Petri disease has been identified as one of the most dangerous for vine plants causing economic losses in cellars worldwide. Petri disease is caused by the infection of different fungal pathogens, mainly, Phaeomoniella chlamydospora, Phaeocremonium minimum and Cadophora luteo-olivacea. The molecular detection of plant pathogens is topical due to its facility, reproducibility and accuracy. Here we have described a PCR protocol based in a pair of new designed specific primers for the rapid detection of C. luteo-olivacea. The described procedure is intended for the direct inspection of plants suspected of being infected. Bovine serum albumin and MgCl2 were used as PCR adjuvants in order to cope with the presence of polymerase inhibitors from wood samples. Several assays have been settled out in order to assign the sensitivity and specificity of the developed technique. Under the conditions tested, the procedure has a low detection limit (10 pg) and it is specific for C. luteo-olivacea detection among other Cadophora species and fungal endophytes of Vitis vinifera.
  • Publication
    The Biology of Pichia membranifaciens Killer Toxins
    (MDPI, 2017-03-23) Belda Aguilar, Ignacio; Ruiz, Javier; Alonso Conde, Rafael Alejandro; Marquina Díaz, Domingo; Santos de la Sen, Antonio
    The killer phenomenon is defined as the ability of some yeast to secrete toxins that are lethal to other sensitive yeasts and filamentous fungi. Since the discovery of strains of Saccharomyces cerevisiae capable of secreting killer toxins, much information has been gained regarding killer toxins and this fact has substantially contributed knowledge on fundamental aspects of cell biology and yeast genetics. The killer phenomenon has been studied in Pichia membranifaciens for several years, during which two toxins have been described. PMKT and PMKT2 are proteins of low molecular mass that bind to primary receptors located in the cell wall structure of sensitive yeast cells, linear (1→6)-β-D-glucans and mannoproteins for PMKT and PMKT2, respectively. Cwp2p also acts as a secondary receptor for PMKT. Killing of sensitive cells by PMKT is characterized by ionic movements across plasma membrane and an acidification of the intracellular pH triggering an activation of the High Osmolarity Glycerol (HOG) pathway. On the contrary, our investigations showed a mechanism of killing in which cells are arrested at an early S-phase by high concentrations of PMKT2. However, we concluded that induced mortality at low PMKT2 doses and also PMKT is indeed of an apoptotic nature. Killer yeasts and their toxins have found potential applications in several fields: in food and beverage production, as biocontrol agents, in yeast bio-typing, and as novel antimycotic agents. Accordingly, several applications have been found for P. membranifaciens killer toxins, ranging from pre- and post-harvest biocontrol of plant pathogens to applications during wine fermentation and ageing (inhibition of Botrytis cinerea, Brettanomyces bruxellensis, etc.).
  • Publication
    Desarrollo de un glosario de términos biológicos en lengua de signos para alumnos de educación secundaria y universitaria.
    (2015) Marquina Díaz, Domingo; Santos de la Sen, Antonio; Alonso Conde, Rafael Alejandro; Portillo Corcho, Alberto; Caballero Gómez, Ana; Arahuetes Portero, Rosa María; Pérez Gomáriz, Rosa; Carballo Cuervo, Serafín; Calvo de Pablo, Pilar; Garcia Moreno, Ana; Arriero Higueras, Elena; Gómez Miguel, Begoña; Pérez Urria Carril, Elena; Gomez Flechoso, Maria de los Angeles; Callejas Hervás, Carmen; Belda Aguilar, Ignacio
    Este proyecto ha permitido crear un glosario de términos biológicos en lengua de signos española. Este glosario permitirá a los alumnos sordos de enseñanza media y superior tener una mayor accesibilidad a los términos específicos de las distintas disciplinas que constituyen las Ciencias Biológicas.
  • Publication
    Looking at the Origin: Some Insights into the General and Fermentative Microbiota of Vineyard Soils
    (MDPI, 2019-08-29) Alonso Conde, Rafael Alejandro; Celis Rodríguez, Miguel de; Ruiz Ruiz, Javier; Vicente Sánchez, Javier; Navascués, Eva; Acedo, Alberto; Ortiz-Álvarez, Rüdiger; Belda, Ignacio; Santos de la Sen, Antonio; Gómez Flechoso, María Angeles; Marquina Díaz, Domingo
    In winemaking processes, there is a current tendency to develop spontaneous fermentations taking advantage of the metabolic diversity of derived from the great microbial diversity present in grape musts. This enological practice enhances wine complexity, but undesirable consequences or deviations could appear on wine quality. Soil is a reservoir of important microorganisms for different beneficial processes, especially for plant nutrition, but it is also the origin of many of the phytopathogenic microorganisms that affect vines. In this study, a meta-taxonomic analysis of the microbial communities inhabiting vineyard soils was realized. A significant impact of the soil type and climate aspects (seasonal patterns) was observed in terms of alpha and beta bacterial diversity, but fungal populations appeared as more stable communities in vineyard soils, especially in terms of alpha diversity. Focusing on the presence and abundance of wine-related microorganisms present in the studied soils, some seasonal and soil-dependent patterns were observed. The Lactobacillaceae family, containing species responsible for the malolactic fermentation, was only present in non-calcareous soils samples and during the summer season. The study of wine-related fungi indicated that the Debaryomycetaceae family dominates the winter yeast population, whereas the Saccharomycetaceae family, containing the most important fermentative yeast species for winemaking, was detected as dominant in summer.
  • Publication
    Creación del primer Grupo iGEM (Competición Internacional de Biología Sintética) de Madrid: Facultad de Biología-UCM
    (Universidad Complutense de Madrid, 2019-01-14) Marquina Díaz, Domingo; Santos de la Sen, Antonio; Alonso Conde, Rafael Alejandro; González Jaén, María Teresa; Quero Lombardero, Francisco Javier; Gómez Flechoso, Mª de los Ángeles; Saiz Gonzalo, Gonzalo; Martín González, Ana María; Belda Aguilar, Ignacio; Armero Hernández, Laura; Serrano Barrero, Susana Lourdes
    En este Trabajo se describe la creación del primer Grupo iGEM de Madrid así como la elaboración de un biosensor que permite la detección de polen de olivo a tiempo real empleando metodos de ingeniería genética y robótica.
  • Publication
    Estudio ecofuncional de la microbiota asociada a suelos de interés vitivinícola
    (2016-09) Alonso Conde, Rafael Alejandro; Marquina Díaz, Domingo
    El suelo es el principal recurso del que disponemos para hacer frente a la creciente demanda mundial de alimentos. Las prácticas agrícolas determinan el uso sostenible del suelo para evitar procesos de desertización y aumentar el rendimiento productivo. En distintas parcelas de suelos con prácticas vitivinícolas se han estudiado las principales variables abióticas y bióticas que contribuyen a un aumento en la producción, atendiendo a los principales estados fisiológicos de la vid. En este estudio se ha determinado la Capacidad de Campo, cuyos valores oscilan entre 42,09 y 165,90 ml H2O/kg de suelo. La medida del pH determina los procesos biogeoquímicos que se cursan en el suelo, en este caso el pH está determinado por presencia de CaCO3, definiendo un suelo fuertemente alcalino. Las actividades fosfatasa y deshidrogenasa son indicadores de la actividad microbiana total del suelo, debido al pH básico, se determinó la actividad enzimática fosfatasa alcalina obteniendo valores de 31,6 mg y 132,9 PNP/kg•h, similares a los encontrados en cultivos de maíz con un pH similar. Los valores obtenidos con la actividad deshidrogenasa están en torno a una media de 44 mg INTF/kg•h, muy superior a la actividad en otros suelos agrícolas. Se ha observado una predominancia de microorganismos viables fijadores de nitrógeno alcanzando el 43% de presencia en el estado fisiológico de Lloro. El SIR durante la fase de Reposo se correlaciona linealmente con el recuento microbiano de heterótrofos (Coef. correlación=0,87). El estado fisiológico de Reposo es el que presenta mayor biodiversidad (Índice de Shannon) edáfica.
  • Publication
    Metagenomic Research of Infectious Diseases in Archaeological Contexts: Evidence from the Hospital Real de Todos-os-Santos (Portugal)
    (MDPI, 2022-06-15) Alves Cardoso, Francisca; Palomo Díez, Sara; Alonso Conde, Rafael Alejandro; Lopes Gomes, Claudia Filipa; Casimiro, Silvia; Banha da Silva, Rodrigo; Arroyo Pardo, Eduardo
    Syphilis is one of the most exciting diseases explored in paleopathology and, therefore, tracing back its origin and development has provided a prolific debate. The combination of paleopathological data with historical sources, iconography, and archaeological contexts were the primary sources used to reconstruct its historical path. However, there are some limitations to paleopathological diagnosis due to the nature of bone reaction to stimuli. In addition, historical sources are subjected to a bias of social and cultural nature and the knowledge of those who wrote them. Hence, ancient DNA analysis offers the possibility of acquiring proof of cause by identifying pathogens in an organism. We undertook a metagenomic study of a skeleton exhumed from the Royal Hospital of All Saints (Portugal), renowned for treating syphilis from the 16th century onwards. The skeleton had previously been diagnosed with syphilis according to paleopathological analysis. However, the metagenomics analysis showed no presence of the pathogen associated with syphilis (i.e., Treponema pallidum) but revealed pathogenic microorganisms related to respiratory diseases (pneumonia), nonspecific bone infections (osteomyelitis), and oral bacterial pathologies as well as Hansen’s disease (also known as leprosy). The results are exciting and demand a reappraisal of the observed bone changes, recontextualizing their characterization as syphilis related. They prove that past reconstruction of health and disease diagnoses based on assessing human osteological remains of known context (such as a syphilitic hospital) may bias interpretations and, therefore, caution is recommended, not forgetting that the absence of evidence is not evidence of absence (in this case of syphilis) in life.