AGCC. Biotecnología Agroambiente y Salud - MICROBIOTA

URI permanente para esta comunidad

https://repositorio.udes.edu.co/handle/001/9446

Navegar

Examinando AGCC. Biotecnología Agroambiente y Salud - MICROBIOTA por Título

Mostrando 1 - 20 de 27
  • Publicación
    Acceso abierto
    Actinobacteria-enhanced plant growth, nutrient acquisition, and crop protection: Advances in soil, plant, and microbial multifactorial interactions
    (2022-02-05) Mitra, Debasis; MondaL, Rittick; Khoshru, Bahman; Senapati, Ansuman; Radha, T. K.; Mahakur, Bhaswatimayee; Uniyal, Navendra; Myo, Ei Mon; Boutaj, Hanane; Guerra-Sierra, Beatriz Elena; Panneerselvam, Periyasamy; Ganeshamurthy, Arakalagud Nanjundaiah; Andelković, Snežana; Vasić, Tanja; Rani, Anju; Dutta, Subhadeep; Das Mohapatra, Pradeep K.; Microbiota
    Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today's huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs. In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants. The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.
  • Publicación
    Acceso abierto
    Actividad Acaricida In Vitro de Compuestos Sobre Schizotetranychus hindustanicus(Hirst), (Acari: Tetranychidae), Ácaro Hindú de los Cítricos
    (2022-02-01) Ortiz-Meneses, Fredy Alejandro; Guerra-Sierra, Beatriz Elena; Osorio-Alvarado, Carlos Enrique; Rodriguez-Gonzalez, Leidy; Microbiota
    El cultivo de lima Tahití(Citrus x latifolia Tanaka ex Q. Jiménez)ocupa un importante porcentaje dentro de la cadenacomercialde los cítricos en Colombia, pero es atacado por Schizotetranychus hindustanicus o ácarohindú, un fitófago que produce lesiones típicas en el haz de las hojas y frutos, caracterizadas por manchas blanquecinas circulares que corresponden a las telarañas que teje la hembra y que le restan valor estético al fruto y a su comercialización. El objetivo del presente estudio consistió en evaluar in vitrolos efectos acaricidas de distintos compuestos en tres tiempos de contacto sobre poblaciones del ácaro.Se evaluó extracto oleaginoso de Neem (Azadirachta indica)al 1,0%, azufre micronizado al 0,5%, extracto acuoso de Azadirachtina 0,4%, filtrado de caldo de ceniza al 15 %. Como control positivo se utilizó Abamectina al 0,2%, producto reconocido por su efecto acaricida, y se usó agua destilada como control negativo. Se evidenció que los tratamientos más efectivos fueronelextracto oleaginoso de Neem-A. indicaal1,0%, azufre micronizado al 0,5%, y Abamectina al 0,2% con valores de mortalidad del 96,4;97,9 y100 % a las 72 horasrespectivamente. Los resultados permiten sugerir el uso de compuestos naturales a base de Azadirachta indicaen soluciones oleaginosas para el control deesta plaga, pues no afectan el ecosistema a la vez que no se han reportado resistencias del fitófago por su uso.
  • Publicación
    Acceso abierto
    Alteraciones anatómicas e histoquímicas ocasionadas por la oidiosis en hojas de Hydrangea macrophylla (Hydrangeaceae)
    (2020-07-03) Rincón-Barón, Edgar Javier; Grisales-Echeverri, Claudia; Cuaran, Viviana Lucia; Cardona-B., Nadya Lorena; Microbiota
    Anatomical and histochemical alterations caused by powdery mildew on Hydrangea mac-rophylla (Hydrangeaceae) leaves. Introduction: There are few studies concerning the morpho-anatomical and histochemical alterations caused by powdery mildew in H. macrophylla leaves in the scientific literature. Objective: To describe and analyze anatomical and histochemical aspects of this pathosystem. Methods: More than 90 leaves of H. macrophylla (both healthy and infected leaves by powdery mildew) were collected in the nursery El Jardín del Eden, Rionegro, Antioquia, Colombia. To carry out the identification of the mycopatho-gen, sections were stained with Lactophenol Blue, and contrasted with specialized taxonomic keys. Transverse fragments 1 cm thick were fixed in a mixture of formalin, alcohol, and acetic acid. These were subsequently dehydrated using an ethanol series, clarified in Xylene, and finally embedded in Paraplast plus® to obtain 5 μm sections. Schiff’s periodic acid reaction (PAS) was used to detect structural and reserve polysaccharides, Ruthenium Red for pectins, Ponseau S and Lacmoid for callose, ferric chloride for polyphenols, Sudan Black for lipids and Uvitex 2B-Hematoxylin for chitin. The sections were observed using a Nikon 80i eclipse® pho-ton microscope, with Uvitex 2B-Hematoxylin-stained sections examined by epifluorescence using a UV-2A filter. For the observation and description of the samples by scanning electron microscopy, healthy and infected leaves were fixed and dehydrated in 100 % methanol, critical point dried, and coated with gold. Results:H. macrophylla leaves are isobilateral and homobaric, with adaxial and abaxial epidermis of a single cellular layer. The palisade parenchyma consists of a layer of short cells, while the spongy parenchyma forms 6 to 7 cellular layers. All vascular bundles in the leaf blade are closed collaterals. Abundant idioblasts with raphides may be observed in the mesophyll, and starch is the main reserve carbohydrate present in the tissues. The leaves are hypostomatic and exhibit a paracytic pattern of superficial stomata which possess large substomatal cavities. The morphological data observed indicate that the mycopathogen is related to the genus Erysiphe. The epidermal cells affected by the pathogen exhibit thickened walls, granular cytoplasm, and papillae or cell wall appositions in the outer periclinal walls. With the deterioration of the epidermis, the underlying tissues are affected and become necrotic. Histochemical test indicate that infected plants thicken and reinforce their epidermal cell walls with primary wall materials; primarily cutin, pectins, and callose. When stained with Sudan Black, the presence of dark-colored agglomerates in the cytoplasm of epidermal cells may be related to plant defense mechanisms; and those observed in mesophilic cells to the disorganization of membrane systems. Polyphenols accumulate in the cytoplasm of infected epidermal cells. The fungal material present in epidermal tissues was clearly differenti-ated when stained with fluorochrome to detect chitin. Conclusions: Species of the genus Erysiphe are causative agents of powdery mildew in H. macrophylla. Necrosis of the epidermal cells is observed in response to the mycopathogen, possibly due to hypersensitive response.
  • Publicación
    Acceso abierto
    Alteraciones histopatológicas causadas por la roya puccinia nakanishikii (Pucciniales: pucciniaceae) en plantas de cymbopogon citratus (poaceae)
    (2020-02-13) Rincón-Barón, Edgar Javier; Gutierrez-Rodriguez, Ana Mariany; Guerra-Sierra, Beatriz Elena; Espinosa Matías, Silvia; Microbiota
    Histopathological alterations caused by Puccinia nakanishikii rust (Pucciniales: Pucciniaceae) in Cymbopogon citratus (Poaceae) plants. Introduction: Histopathological and histochemical aspects linked to the attack of fungal rusts to plants, as well as its relation with the different spore stages are topics rather scarce in the scientific literature. Objective: To describe and analyze the histopathological and histochemical aspects of Cymbopogon citratus and its relation with the different stages of the spores from the rust fungi Puccinia nakanishikii. Methods: During the months April and August 2013, leaves healthy and infected by Puccinia nakanishikii were collected in the Northwestern scarp of the Bucaramanga-Colombia plateau. The samples with injuries on diverse developmental stages were fixated and processed according to the standard protocols for embedding and sectioning in paraffin and resin. Sections obtained from paraffin (5-7 μm) were stained with Safranin-Alcian blue and Alcian blue-Hematoxylin. On the other hand, sections obtained from resin (0.5 μm) were stained with Toluidine blue. Further, freehand sections were obtained for an autofluorescence analysis. The observations and photographic record were done via photonic microscope and epifluorescence microscope. For the observations via scanning electron microscopy (SEM), the samples were fixated in Glutaraldehyde, dehydrated with 2,2 dimethoxypropane, then desiccated to critical point and finally coated with gold. Results:The leaves are generally hypostomatic, with long and short epidermic cell forming parallel rows and showing unicellular prickle trichomes and micro-trichomes. The abaxial surface is covered by epicuticular wax forming a dense layer. The adaxial epidermis is formed by groupings of bulliform cells and epidermal cells with rectangu-lar or squared contour. In the mesophyll, there is no differentiation between palisade and spongy parenchyma, its anatomy reflects the C4 metabolism. The formation of uredosori and teliosori both hypophyllous was observed. Urediniospores are the reinfecting agents phase, they have 4-5 equatorial germ pores and echinulate wall. Teliospores have smooth wall and a persistent pedicel. The urediniospores form a germ tube, generally on the abaxial leaf surface, these tubes develop towards the stomata reaching the mesophyll interior. No appressorium were observed. The epidermis limiting the uredosorus detaches due the development and pressure that exert both the urediniospores and capitate paraphyses. As the infection progresses, autofluorescense of the chloro-phyll is lost and the cells undergo necrotic processes. Afterwards, the phloem collapses and the xylem becomes slightly disorganized. At this moment, the infection is extended along the whole leaf blade, resulting in the leaf death and the plant defoliation. On advanced stages of the infection, the uredosori showed pycnidia, probably belonging to the hyperparasite Sphaerellopsis, these structures were closely associated to the rust infected tissues. Conclusions:Puccinia nakanishikii develops on the leaves of Cymbopogon citratus producing uredosori and teliosori. Urediniospores are the reinfective stage, teliospores were only observed at late stages of the infection. The epidermis and photosynthetic tissue are severely affected by cell necrosis. The vascular tissues are deeply affected on the advances stages of the infection.
  • Publicación
    Acceso abierto
    Antifungal activity of acidic electrolyzed water against strawberry postharvest molds (Fragaria x ananassa Duch cv. Camarosa)
    (2019-04-01) Guerra-Sierra, Beatriz Elena; Sandoval-Meza, Adriana Ximena; García-Sanchéz, Liliana Torcoroma; Microbiota
    The aim of this word was to assess the in vitro antifungal activity of acidic electrolyzed water (AEW) and the required contact time to inhibit the development of post-harvest molds common in strawberry fruit. Ninetyfour strawberry samples were used. A five-fold assay in a randomized design was carried out using standard inoculum of fungal conidia, which were subjected to an array of contact times and AEW concentrations, using a controlled agitation (120 r.p.m) at 23°C. The conidia treated with AEW were grown on potato dextrose agar and their germination was evaluated. Mycelial growth of the treated samples was measured and compared against conidia control samples treated with distilled water instead of AEW. Botrytis cinerea and Rhizopus stolonifer were the most commonly isolated species at 54.25% and 28.72%, respectively. AEW inhibited conidia germination after 7 minutes of exposure. The AEW concentration required to inhibit conidia germination was 10 ppm and 50 ppm for R. stolonifer and B. cinerea respectively, a variance possibly due to the constitution of their cellular walls. A short exposure of AEW is able to inhibit post-harvest fungi growth, and is thus recommended as an efficient, economical, and environmentally sustainable sanitation agent, with the ability of extending the strawberry postharvest consumption period.
  • Publicación
    Acceso abierto
    Antifungal effect of zinc oxide nanoparticles (ZnO-NPs) on Colletotrichum sp., causal agent of anthracnose in coffee crops
    (2020-05-05) Mosquera-Sanchez, L.P.; Arciniegas-Grijalba, P.A.; Patiño-Portela, M.C.; Guerra–Sierra, Beatriz Elena; Muñoz-Florez, J.E.; Rodríguez-Páez, J.E.; Microbiota
    Coffee cultivation around the world is affected by phytopathogenic fungi, among them Colletotrichum sp., the causative agent of anthracnose. In the present work, therefore, an in vitro study was carried out on the antifungal effect of zinc oxide nanoparticles (ZnO-NPs) obtained by a chemical route on Colletotrichum sp. To this end, the area of growth of the fungus exposed to the action of concentrations of 9 mmolL−1 (730 ppm), 12 mmolL−1 (980 ppm), and 15 mmolL−1 (1200 ppm) of ZnO-NPs was monitored and their behavior was compared with the effect of the fungicide, ciproconazole (positive control) as well as with a sample of the fungus that grew normally (negative control). The ZnO-NPs showed an appreciable percent inhibition of fungal growth, ~96% for the concentration of 15 mmolL−1 at 6 days, causing loss in the continuity of some hyphae and the formation of groups of hyphal structures. Additionally, the ZnO-NPs favored the formation of structures of compact appearance (similar to vacuoles) within the hypha, as well as decreasing the cytoplasmic space.
  • Publicación
    Acceso abierto
    Arbuscular mycorrhizal fungal association boosted the arsenic resistance in crops with special responsiveness to rice plant
    (2022-01-05) Mitra, Debasis; Saritha, Boya; Janeeshma, Edappayil; Gusain, Poonam; Khoshru, Bahman; Abo Nouh, Fatma A.; Rani, Anju; Olatunbosun, Adeyemi N.; Ruparelia, Janki; Rabari, Aniruddh; Mosquera-Sánchez, Lyda P.; Mondal, Rittick; Verma, Devvret; Panneerselvam, Periyasamy; Das Mohapatra, Pradeep K.; Guerra-Sierra, Beatriz Elena; Microbiota
    Arsenic (As) is a potentially toxic metalloid classified as a group 1 carcinogen, released in the soil environment because of natural as well as different anthropogenic activities. The presence of excess As content in soil and irrigation water enhances the As accumulation in rice grains. Millions of people who consume these contaminated grains are exposed to severe health issues. Increased arsenic uptake causes oxidative stress in plants, which combats by inducing the expression of several genes and signaling the biosynthesis of various antioxidants and phytochelatins. As toxicity reduces crop productivity, so it's critical to improve plant growth in As-contaminated environments while minimizing metal translocation to grains. Arbuscular mycorrhiza fungi (AMF) is considered a sustainable way to tolerate As toxicity. Organic pollutants metabolism by AMF, degradation of these soil contaminants by AMF exudation enzymes, and elimination of the pollutants by plant uptake and accumulation are the principal mechanisms of AMF mediated bioremediation. However, plant responses are established to vary with the host plant and the species of AMF. In our review, we showed that understanding the community composition, diversity, and gene regulation of AMF in the rice ecosystem played a critical role in maximizing As uptake and their potential in sustainable rice and other crops production. It has been reviewed that AMF has the potential to survive in an extremely As toxic condition and it potentially aids to improve the tolerance level of host plants.
  • Publicación
    Acceso abierto
    Contribución a la conservación de Orchidiaceas de Santander mediante cultivo in vitro de semillas
    (Bucaramanga : Universidad de Santander, 2018, 2018-12-01) Chacón Velasco, Martha Rocío; Contreras Acero, Olga Marina; Cáceres Cárdenas, Helmar Ernesto; Universidad de Santander
    El registro de la diversidad de orquídeas en Colombia es sorprendente; los inventarios realizados emiten cálculos aproximados, pero se modifican en la medida que se exploran diversas áreas. Estudios realizados en Santander en el 2011 precisaron la existencia de cerca de 3.500 a 4.000 especies en más de 230 géneros, cifra que corresponde al 10 % de las especies existentes y al 25 % del total de los géneros a nivel mundial. Para 2012 fueron reportadas 4.010 especies distribuidas en 260 géneros y en el 2013 se presentó un registro de cerca de 4.100 especies agrupadas en 232 géneros. Para el 2015 el Ministerio de Ambiente y Desarrollo Sostenible a través del Sistema de Información sobre Biodiversidad de Colombia (SIB) afirmó que Colombia cuenta con el mayor número de especies de orquídeas en el mundo, con un total de 4.270 registradas, agrupadas en 274 géneros distribuidos en casi todo el territorio nacional; un total de 1.572 especies son exclusivas del país. El departamento de Santander ocupa actualmente el segundo lugar en riqueza, con un 14 %, de orquídeas a nivel nacional después del departamento de Antioquia. Santander presenta especies endémicas con distribución restringida. Sea el caso mencionar a Catasetum lucis, Sobralia uribei y Santanderella amadorinconiana, las cuales no cuentan con protección para su conservación. Los investigadores del Instituto Humboldt elaboraron una lista de especies amenazadas en Colombia y mencionaron que las familias con mayor número de especies en peligro son las orquídeas, seguidas de las palmas y las pasifloráceas (Ochoa, 1998). Dentro de las principales causas de extinción está la destrucción de sus hábitats y expansión de la frontera agrícola como las de mayor impacto, que hace prioritario plantear estrategias para frenar la pérdida de especies; entre ellas: la conservación in situ de áreas donde se encuentran los árboles hospederos, insectos y hongos micorrízicos, entre otros. Pero además la ejecución de proyectos de investigación que propendan por la creación tanto de bancos de germoplasma (preservación de semillas, células, tejidos, órganos o plantas bajo cultivo in vitro o nitrógeno líquido), así como el cultivo de plantas en vivero. De igual manera los estudios en los aspectos taxonómicos, poblacionales, interacciones ambientales, polinización, biología reproductiva, propagación in vitro y ex situ serán de gran impacto para la protección de este recurso floral nativo. El ciclo de vida sexual de las orquídeas comprende la germinación de semillas, desarrollo de protocormos, diferenciación de plantas, etapa reproductiva o floración, polinización, fecundación y dispersión de semillas. El porcentaje de germinación de las semillas de Orchidaceas en condiciones naturales es muy bajo en comparación con el número de semillas producido en cada cápsula; esto obedece a que la cubierta alberga un embrión que no almacena sustancias nutritivas. Por ello estas deben encontrar soportes adecuados como cortezas de árboles que les suministre nutrientes y establecer asociación micorrízica con hongos basidiomicetes del grupo Rizocthonia sensu latu, un grupo artificial que incluye hongos cuyas etapas sexuales pertenecen a los géneros Thanatephorus, Ceratobasidium, Sebacina y Tulasnella para garantizar de manera exitosa el proceso germinativo. La técnica de cultivo in vitro está siendo usada en varios países como uno de los medios que permiten conservar poblaciones silvestres , así como el desarrollo de paquetes tecnológicos adoptados por horticultores, comunidades organizadas e interesadas en la explotación racional de sus recursos para disminuir en gran medida la presión de la colecta de poblaciones silvestres (Salazar y Mata, 2003). Además dicha técnica favorece la variabilidad genética de las poblaciones (Arditti, 1993). El cultivo de semillas de orquídeas como modalidad del cultivo in vitro de las plantas superiores, tiene como finalidad el acortamiento del ciclo de mejora, sustitución de la simbiosis (micorrizas) y evitar la competición con otros microorganismos. Se espera que el presente documento pueda brindar a estudiantes de diferentes disciplinas, cultivadores y toda persona amante de las orquídeas las bases para comprender el ciclo de vida de las orquídeas, el estado de vulnerabilidad que presentan algunas especies de la región y el papel protagónico que ha tenido hasta el momento la técnica del cultivo in vitro de semillas como herramienta de propagación alterna para incrementar el volumen poblacional a nivel mundial y nacional de las orquídeas endémicas.
  • Publicación
    Acceso abierto
    Differential anti-proliferative effect on K562 leukemia cells of Lippia alba (Verbenaceae) essential oils produced under diverse growing, collection and extraction conditions
    (2017-02) García Sánchez, Liliana Torcoroma; Leal, Andrés Felipe; Moreno Moreno, Erika Marcela; Stashenko, Elena E.; Arteaga, H. José
    Lippia alba (Verbenaceae Family) is an aromatic shrub native to Latin America, with recognized medicinal properties and a well-known high phenotypical plasticity in response to environmental factors. In order to identify the parameters that potentiate its in vitro anti-proliferative effect on human leukemia cells (K562), a matrix was designed for the production of 76 essential oils (EOs) with variations in plant growing season, harvested part from the plant, and preservation and distillation material conditions. The results show that EOs obtained from the same L. alba chemotype (Citral or Carvone), but acquired under different environmental or extraction conditions, presented significant differences in their primary components, oil yield, and cytotoxic activity on K562 cells. Citral EOs produced under diverse conditions displayed a cytotoxic effect on tumour cells ranging from 54 to 95% (IS 1.8–8.6) and IC50 from 13 to 38.8 μg/mL. The differences in antiproliferative activity were significantly correlated with variations in the β-caryophyllene oxide concentration. These results show the value of using standardized production conditions for the commercial utilization of L. alba EOs.
  • Publicación
    Acceso abierto
    Evaluación de la patogenicidad de Xenorhabdus spp. nativos en Colombia
    (2014-07) Guerra-Sierra, Beatriz Elena; Chacón, Julie Giovanna; Muñoz Flórez, Jaime Eduardo; Caicedo, Ana Milena
    Xenorhabdus and Photorhabdus bacteria are symbiotically associated with nematodes of the Steinernematidae and Heterorhabditidae families respectively. They are characterized by producing a complex of substances such as toxins, antibiotics and extracellular enzymes that kill insects. In order to select the most pathogenic nematodes and antibiotic production level, it was propose to evaluate the pathogenicity of 13 native isolates. Bacteria were isolated from infective juveniles (JIS) by direct macerated, cultured on selective media (NBTA and MacConkey) and described phenotypic and biochemically. The pathogenicity was evaluated on the last instar larvae of G. mellonella, using serial dilutions of the bacterial inoculum with a concentration of 104cel/ml. The mortality rate was registered at 12, 24 and 48 hours and the colony forming units (CFU) in NBTA agar in the same intervals of time. The data were analyzed by variance analysis and mean comparison by Duncan test. Biochemical and enzymatic tests were positive for the genus Xenorhabdus. The results showed that the isolates UNPX04, UNPX15 from agricultural soils of Florida -Risaralda and Llano Bajo- Valle del Cauca respectively, caused 100% of mortality at 12 and 24 hours in contrast with seven isolations that caused only 70% of mortality.
  • Publicación
    Acceso abierto
    Evolution of the porous structure of cocoa beans during microwave drying
    (2020-07-05) Alean, Jader; Chejne, Farid; Maya, Juan C.; Camargo-Trillos, Diego; Ramírez, Say; Rincon-Baron, Edgar Javier; Rojano, Benjamin; Microbiota
    In this work, it was evaluated the morphological changes of the porous structure of the cocoa bean samples subjected to microwave drying. The use of microwaves (MWs) applied by ON-OFF on cocoa bean samples allowed to avoid both the burning and the roasting of the beans. During the MWs drying process, phenomena of breakage of cellular structure, coalescence and, pore plugging altered the average pore diameter, the pore volume, surface area, and Pore Size Distribution (PSD). When the results of sun-dried beans were compared with those of beans dried by MWs, it was concluded that the average pore diameter, the pore volume, the surface area and, PSD were also affected by the solar drying; however, the breakage of cellular structure did not occur.
  • Publicación
    Acceso abierto
    First record of Chlorophyllum molybdites (G. Mey.) Massee (Basidiomycota, Agaricales, Agaricaceae) from Bucaramanga, Department of Santander, Colombia
    (2022-05-09) Olarte-Castillo, Ximena A.; Antolínez-Delgado, Carlos Andrés; Microbiota
    Colombia is a megadiverse country with many macrofungi species. Despite their ecological, anthropological, and economic importance, the distribution of many macrofungal species is still scarcely known in this country. Chlorophyllum molybdites (G. Mey.) Massee is a poisonous macrofungus common in urban settings of tropical and subtropical regions. In Colombia it has only been reported in three of 32 departments. To fill this gap in knowledge we morphologically describe for the first time C. molybdites from the city of Bucaramanga, Department of Santander, extending the known distribution of this macrofungus in Colombia.
  • Publicación
    Acceso abierto
    Foliar anatomy of ten genotypes of the plant manihot esculenta (Euphorbiaceae)
    (2020-07-03) Marín, Jaime; Rincón-Barón, Edgar Javier; Montoya-Lerma, James; Microbiota
    Cassava Manihot esculenta (Crantz) is a perennial shrub native to South America that is an essential source of carbohydrates for more than 600 million people in tropical countries. Objective: The aim of this study was to describe and compare the leaf blade anatomy of ten genotypes of cassava. Methods: The methodology for anatomical descriptions was processed and 30 leaves of each of the varieties were included and sectioned according to paraffin impregnation protocols. Results: The results showed that the leaf blade anatomi-cal structure of all the varieties in general terms show differences. All varieties had monostratified epidermis, leaf mesophyll consisted of a palisade parenchyma in a single layer and multiple layers of spongy parenchyma. Polyphenolic idioblasts were observed immersed in the palisade parenchyma and spongy parenchyma. Between 3-7 xylem ribs with their respective phloem were found in the midrib in almost all varieties. Trichomes were only found in two varieties (NAT31-ECU72) and leaves were all hipostomatic. Conclusions: The results reveal that NAT31 is the material with the most anatomically marked differences (i.e. presence of trichomes, papil-lary cell, and, on the adaxial face, special provision in the arrangement of stomata and epicuticle wax patterns), characteristics that might be related to pest resistance.
  • Publicación
    Acceso abierto
    Fungal Endophytes of Tahiti Lime (Citrus citrus × latifolia) and Their Potential for Control of Colletotrichum acutatum J. H. Simmonds Causing Anthracnose
    (2021-04-01) Muñoz-Guerrero, Jaider; Guerra-Sierra, Beatriz Elena; Alvarez, Javier C.; Microbiota
    Colletotrichum acutatum is one of the causal agents of anthracnose in several crops, and of post-flowering fruit drop (PFD) in citrus and key lime anthracnose (KLA). The pathogen normally attacks flowers, causing lesions only in open flowers. Under very favorable conditions, however, it can also affect flower buds and small fruits, causing complete rotting of the fruit and a premature fall, resulting in major economic crop losses. We isolated endophytic fungi from Tahiti lime to evaluate its diversity, verify its antagonistic capacity against the phytopathogen Colletotrichum acutatum C-100 in dual tests, and evaluate the ability of various endophytic agents to control flowers with induced anthracnose. 138 fungal isolates were obtained from 486 fragments of branches, leaves, and fruit; from which 15 species were identified morphologically. A higher isolation frequency was found in branches and leaves, with a normal level of diversity compared to other citrus species. Of the 15 morphospecies, 5 were trialed against C. acutatum in antagonism tests, resulting in a finding of positive inhibition. 2 endophytic fungi from the antagonism tests demonstrated high inhibition of the phytopathogen, and were thus used in in vivo tests with Tahiti lime flowers, applied in a spore solution. Spore solutions of two molecularly identified species, Xylaria adscendens, and Trichoderma atroviride, reduced the lesions caused by the phytopathogen in these in vivo tests. The finding that these endophytes react antagonistically against C. acutatum may make them good candidates for further biological control research in an agroindustry that requires environmental sustainability.
  • Publicación
    Acceso abierto
    Impacts of Arbuscular Mycorrhizal Fungi on Rice Growth, Development, and Stress Management With a Particular Emphasis on Strigolactone Effects on Root Development
    (2021-03-15) Debasis, Mitra; Guerra Sierra, Beatriz Elena; Bahman, Khoshru; De Los Santos Villalobos, Sergio; Belz, Claudia; Chaudhary, Priya; Shahrig, Faride Noroozi; Rihab, Djebaili; Nurudeen, Olatunbosun Adeyemij; El-Ballatk, Enas M.; El-Esawik, Mohamed A.; Moradic, Shokufeh; Mondall, Rittick; Senapati, Ansuman; Panneerselvam, Periyasamy; Das Mohapatra, Pradeep K.; Microbiota
    Arbuscular mycorrhizal fungi (AMF) are widely distributed soil-borne microorganisms, which have a symbiotic relationship with several terrestrial plants. They play a key role in plant growth promotion and development, plant nutrient homeostasis, soil nutrient management, and induction of plant defense mechanisms against pest infestation and disease incidences. This interaction of AMF with rice plants has been studied in great detail, providing distinct perspectives on the natural basis of nutrient transport, stress management, improvement of soil health, and induction of systemic plant resistance. This review highlights the responses of (i) AMF interaction with rice plants, (ii) AMF colonization and sporulation potential in rice rhizosphere, (iii) AMF species as a source of inoculum for rice production, (iv) AMF for rice plant maintenance and durability, and (v) AMF responses to other soil microorganisms. Additionally, a new class of phytohormones known as strigolactone (SLs) has been briefly described covering the various forms of analogs, isomers, and membrane transporters. The role of SLs in pre-symbiotic molecular talks, induction of energy metabolism in mitochondria, spore germination, stimulation of hyphal branches, and the relationships of SLs synthesis with soil nutrient content provides in-depth insights into the mechanisms involved in improving AMF interactions with rice plants.
  • Publicación
    Acceso abierto
    Indigenous arbuscular mycorrhizal fungi in oil palm soils in Colombia
    (2013-09) Guerra Sierra, Beatriz Elena; Serge, Sokolski; Dion, Patrice
    Generally monocultures have replaced tropical forests and other ecosystems, causing big changes and little is known about the influence of the practice of monoculture in density and biodiversity of mycorrhizal fungi (AMF) species. Spore production is highly depend of physiologycal parameters of the AMF and on environmental conditions, however it is known that in nutrient-poor soils of the humid tropics many plants are obligate mycotrophs or ecologically dependent on AMF. In Oil palm (Elaeis guineensis Jacq), the limited development of their root system and field observations of high levels of mycorrhizal colonization, suggest that this crop benefits greatly from the symbiosis.[1]Isolation of soil spores and subsequent microscopic examination is a routine procedure in the recognition of AMF species, however the study of walls by light microscopy is a difficult task; interpretation depends on several factors such as the type of microscope and lighting mounting means and observer experience.Based on the morphological characteristics of the AMF described approximately 200 species (2).As a complement to morphological studies AMF wall light microscopy has been used transmission electron microscopy (TEM) and scanning electron microscopy (SEM), however the publications in this field are limited. Another limitation of morphologycal identification is the fact that field- collected spores are often parasitized or degraded and therefore unidentifiable. A methodology for increased healthy spores are AMF trap cultures ,soil samples from the field site are brought into contact with suitable plant hosts of AMF under controlled conditions in order to propagate the species, additionally the plant species used in the trap cultures may have an influence on which AMF are detected , aditionaly the molecular identification is a good tool for the identification of AMF, almost all identification systems for AMF are based on the ribosomal DNA (rDNA) , this is highly polymorphic in single spores of AMF. The aim of this study was to determine the initial density of native mycorrhizal fungi spores in soils of oil palm monocultures, and the identification of AMF species increased in trap cultures under controlled greenhouse conditions . Mycorrhizal fungi spores were identified using optical and scanning microscopy, and molecular analysis was useful for identifying some species of Glomus.
  • Publicación
    Acceso abierto
    Inhibition of C. albicans dimorphic switch by cobalt(II) complexes with ligands derived from pyrazoles and dinitrobenzoate: Synthesis, characterization and biological activity
    (2019-07-01) Fonseca, Daniela; Leal-Pinto, Sandra Milena; Roa-Cordero, Martha Viviana; Vargas, Jose D.; Moreno-Moreno, Erika Marcela; Macias, Mario A.; Suescun, Leopoldo; Muñoz-Castro, Alvaro; Hurtado, John J.; Microbiota
    Seven cobalt(II) complexes of pyrazole derivatives and dinitrobenzoate ligands were synthesized and characterized. The single-crystal X-ray diffraction structure was determined for one of the ligands and one of the complexes. The analysis and spectral data showed that all the cobalt complexes had octahedral geometries, which was supported by DFT calculations. The complexes and their free ligands were evaluated against fungal strains of Candida albicans and emerging non-albicans species and epimastigotes of Trypanosoma cruzi. We obtained antifungal activity with a minimum inhibitory concentration (MIC) ranging from 31.3 to 250 µg mL−1. The complexes were more active against C. krusei, showing MIC values between 31.25 and 62.5 µg mL−1 . In addition, some ligands (L1–L6) and complexes (5 and Co(OAc)2 · 4H2O) significantly reduced the yeast to hypha transition of C. albicans at 500 µg mL−1 (inhibition ranging from 30 to 54%). Finally, the complexes and ligands did not present trypanocidal activity and were not toxic to Vero cells. Our results suggest that complexes of cobalt(II) with ligands derived from pyrazoles and dinitrobenzoate may be an attractive alternative for the treatment of diseases caused by fungi, especially because they target one of the most important virulence factors of C. albicans.
  • Publicación
    Acceso abierto
    Mycorrhizal science outreach: Scope of action and available resources in the face of global change
    (2021-07-07) Silva-Flores, Patricia; Argüelles-Moyao, Andrés; Aguilar-Paredes, Ana; Simões Calaça, Francisco Junior; Duchicela, Jessica; Fernández, Natalia; Furtado, Ariadne N. M.; Guerra-Sierra, Beatriz Elena; Lovera, Milagros; Marín, César; Neves, Maria Alice; Pezzani, Fabiana; Rinaldi, Andrea C.; Rojas, Krystel; Vasco-Palacios, Aida Marcela; Microbiota
    Societal Impact StatementMycorrhizal associations are acknowledged as key components of global ecosystem functioning. This is especially relevant in the context of global change, since they contribute to the amelioration of adverse soil conditions and play crucial roles in ag-riculture. Generally speaking, the lay public is uninformed on the importance of myc-orrhizal fungi and symbiosis to our planet. Therefore, mycorrhizal scientific outreach activities are of paramount importance in order to bridge the aforementioned gap. We think that informing people about the benefits of mycorrhizal fungi and symbiosis in the face of global change, will raise general awareness of relevant research and aid conservation efforts.SummaryScience outreach has become a particularly important duty in shortening the knowledge gap between scientists and the public, in order to strengthen societal decision- making power in the global change crisis. Mycorrhizal fungi and mycor-rhizal symbioses are key components of terrestrial ecosystems that contribute significantly to endure and reduce certain negative global change effects. Their importance has been gaining recognition in academic circles, but not among the general public. The aim of this article is to encourage as many mycorrhizal fungi re-searchers around the world as possible to build, through science outreach, a bridge between their scientific work and public interest. To this end, we conducted a re-view and discussed the relationship between global change and the mycorrhizal symbiosis. We highlight potential audiences, tools, resources, activities, outreach models, pros and cons, as well as the quantification potential for the outreach ac-tivities success. We extend an invitation to all mycorrhizologists around the world to contribute with mycorrhizal outreach material. Contributions will become avail-able on the South American Mycorrhizal Research Network website for individuals or organizations interested in starting or innovating in mycorrhizal science out-reach activities. Finally, the hashtag #mycorrhizalscienceoutreach is proposed to be used whenever a mycorrhizal fungi- related science outreach activity is shared in social media.
  • Publicación
    Acceso abierto
    A new Multiplex-PCR for urinary tract pathogens detection using primer design based on an evolutionary computation method
    (2015-06) García Sánchez, Liliana Torcoroma; Cristancho, Laura Maritza; Vera, Erika Patricia; Begambre, Oscar
    This work describes a new strategy for optimal design of Multiplex-PCR primer sequences. The process is based on the Particle Swarm Optimization-Simplex algorithm (Mult-PSOS). Diverging from previous solutions centered on heuristic tools, the Mult-PSOS is selfconfigured because it does not require the definition of the algorithm’s initial search parameters. The successful performance of this method was validated in vitro using Multiplex-PCR assays. For this validation, seven gene sequences of the most prevalent bacteria implicated in urinary tract infections were taken as DNA targets. The in vitro tests confirmed the good performance of the Mult-PSOS, with respect to infectious disease diagnosis, in the rapid and efficient selection of the optimal oligonucleotide sequences for Multiplex-PCRs. The predicted sequences allowed the adequate amplification of all amplicons in a single step (with the correct amount of DNA template and primers), reducing significantly the need for trial and error experiments. In addition, owing to its independence from the initial selection of the heuristic constants, the Mult-PSOS can be employed by non-expert users in computational techniques or in primer design problems.
  • Publicación
    Acceso abierto
    Nueva reacción en cadena de la polimerasa múltiple para el diagnóstico específico de especies implicadas en la candidiasis humana
    (2017-06) García Sánchez, Liliana Torcoroma; Luna, Liany Johanna; Velasco, Tania Katherine; Guerra Sierra, Beatriz Elena
    Introduction: Candidiases is a group of opportunistic infections caused by yeasts belonging to the genus Candida. Candida albicans is the most prevalent species in both superficial and deep infections, however, the clinical importance of non-albicans Candida has increased during the last decade, driving an urgent need for diagnostic tests that allow for species-level resolution and selection of the optimum therapeutic approach.Objective: To design and to optimize a new multiplex PCR assay for the simultaneous identification of the five most relevant species of Candida involved in human candidiasis etiology.Materials and methods: For primers design, the physical and thermodynamic restrictions that affect multiplex PCR performance were analyzed using Gene Runner and Mult-PSOS. As templates, the internal transcribed region 2 (ITR2) was selected for C. albicans (AJ249486.1), and topoisomerase II (TOPII) for C. parasilopsis (AB049144.1), C. krusei (AB049139.1), C. tropicalis (AB049141.1), andC. guillermondii (AB049145.1). We used ATCC strains of all these five species and clinical isolates as templates.Results: We designed ten oligonucleotides for the simultaneous amplification of the Candida species. The electrophoresis band profile was: C. albicans (206 bp), C. guillermondii (244 bp), C. tropicalis (474 bp), C. parasilopsis (558 bp), and C. krusei (419 bp). Conclusion: The new multiplex PCR assay designed in this study allowed a simultaneous and efficient amplification of the amplicons corresponding to the five species of Candida under study, with an adequate resolution in standard agarose gel.