Browsing by Author "Ramírez Castrillón, Mauricio"
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Item Comparison of two techniques for the detection of environmental fungi in a university campus(2021) Bejarano, Luz Dary Caicedo; Ñañez, Cristhian Delgado; Ramírez Castrillón, Mauricio; Giraldo, Álvaro León Rúa; Vivas, Mónica ChavezFungal contamination in closed or open environments has been well reported. However, studies that address airborne spores trap methods are scarce. In this study, two techniques were evaluated to detect fungal spores in the environment of three buildings of campus of a university in the city of Cali, Colombia. The gravimetric method of spore trapping was compared with the volumetric method (Air Ideal 3P) using the Omeliansky formula to determine the spore abundance. Environmental sampling was performed quarterly for a period of 12 months using dichloran rose bengal chloramphenicol agar. A total of 64,497 CFU/m3 were counted, of which 34,930 CFU/m3 were isolated using the volumetric method and 29,567 CFU/m3 using the gravimetric method. No significant statistical differences were observed between the two techniques (P = 0.0739). The predominant genera obtained with both methods were Cladosporium, Penicillium, Aspergillus, and Fusarium, which suggests that although the gravimetric method is not as efficient as the volumetric method, it is reliable in estimating environmental fungal contamination.Item Dermatofitos en suelos del zoológico de la ciudad de Cali, Colombia(Universidad Santiago de Cali, 2022) Quintero Barragán, Daniel; Grisales Toro, Anyelly; Caicedo Bejarano, Luz Dary; Ramírez Castrillón, MauricioThe dermatophyte fungi present in the soils of the animal houses of the Zoological of the city of Cali, Colombia, were studied. The objective of the study was to determine the presence of dermatophyte fungi in these habitats and the variation of their presence according to some physicochemical parameters of the soil. The Vanbreuseghem hair-hook technique was used, and measurements of pH, conductivity, organic matter, ash, and moisture percentage were also taken. 37/60 (61.6%) of the samples were positive for the Nannizzia gypsea complex; no other dermatophyte was isolated. Soil pH values ranged from 4.63 to 9.36 and the isolation rate of the fungus was higher in soils with a pH range of 5.5 to 6.9 and this difference was statistically significant. The other physicochemical parameters were not significant for the presence of the fungusItem Dominant yeasts associated to mango (Mangifera Indica) and rose apple (syzygium malaccense) fruit pulps investigated by culture-based methods(Academia Brasileira de Ciencias, 2019-07-02) Ramírez Castrillón, Mauricio; Usman, Luisa m.; Silva bedoya, Lina m.; Osorio Cadavid, EstebanThe biotechnological potential of yeasts associated to different habitats in Colombia has been poorly studied, especially the yeasts associated with different plant structures. Fruit pulps are interesting substrates mainly for the growth of yeast species, that can positively affect the productivity and quality of some bioeconomic species. Therefore, the objective of this study was to identify the dominant yeast species associated with mango and rose apple fruit pulps in Cali, Colombia. A total of 90 isolates were obtained, which were grouped considering their colony morphology. The D1/D2 domain of the large ribosomal RNA gene (LSU rRNA gene) or internal transcribed spacer (ITS) 1, ribosomal gene 5.8S and ITS 2 (ITS) regions of one to several representative isolates from each group was sequenced and compared with type strains for identification. The species Hanseniaspora thailandica, H. opuntiae and Clavispora lusitaniae were reported as shared by both fruits, specific for rose apple (H. uvarum, Pichia terricola, Rhodosporidiobolus ruineniae and Candida albicans), or for Mango (Meyerozyma caribbica, M. guilliermondii, C. natalensis, Aureobasidium pullulans, Pichia sp., Saturnispora diversa and C. jaroonii). Two morphotypes were not identified at the taxonomic level of species and were reported as candidates for new species, belonging to the genera Wickerhamomyces and Pichia.Item Environmental yeast communities in vineyards in the mountains of Santa Catarina State, Brazil(Springer Netherlands, 2017-05-26) C. Mendes, S. D.; Ramírez Castrillón, Mauricio; Feldberg, N. P.; Bertoldi, F. C.; Valente, P.Yeasts were isolated from three vineyards located in the South Region of Brazil. A cross evaluation was carried out at the oldest vineyard of the study in Pinheiro Preto. Samples of grape berries, grapevine leaves and the soil, along with samples of the winery equipment and effluent, were collected. In the Serra do Marari and Campos Novos vineyards only samples of grape clusters were obtained. The 106 yeast isolates were identified by sequencing the D1/D2 domain of LSU rDNA or ITS1-5.8S-ITS2 region in 22 species. The values for the richness indices varied between the vineyards. A comparison of the taxonomic diversity of the yeasts from these regions using the reciprocal Simpson index showed a significant difference between the Serra do Marari and Campos Novos vineyards (5.72 ± 0.36 and 2.92 ± 0.36, respectively, p < 0.0001). The functional diversity was assessed in relation to the use of carbon and nitrogen sources by the yeasts isolated from each location. In general, we observed that the Pinheiro Preto and Campos Novos vineyards differed consistently from the Serra do Marari vineyard according to these indices (FAD2, FDc and Rao, p < 0.0001). The possible spreading of Saccharomyces cerevisiae from the winery to the vineyard in Pinheiro Preto was observed.Item Evaluación fisicoquímica y microbiológica de las rutinas de limpieza de las áreas de extracción de jugos para la producción de sacarosa(Universidad Santiago de Cali, 2022) Quiceno García, Angela Patricia; Ramírez Castrillón, Mauricio; Caicedo Bejarano, Luz DaryCleaning routine in the sugar mill is a factor that contributes to increasing on the percentage of undetermined losses in sugar production, by saccharose inversion, and has a negative economic effect due to the decrease in income. This research recorded and evaluated the cleaning routines of a sugar mill in the Valle del Cauca region, by measuring volatile acidity, lactic acidity, determination of mannitol, and indicators of sucrose inversion, among others. According to this methodology, it was possible to associate the changes made in the structure of these routines with the estimated investment and the difference in purities of the cane juice. The evaluation of metabolites produced by lactic acid bacteria and acetic acid bacteria showed a decrease in lactic acidity and volatile acidity after the semi-annual routine, in addition, it identified two possible points of contamination in the daily cleaning routines. The stoichiometric relationship for the determination of mannitol, allowed to calculate of a balance at the experimental level, which resulted in an estimated loss of 60 Quintales of sugar (QQA) daily. Microbiological analysis of the mill tandem allowed the isolation of six strains of lactic acid bacteria identified as Lactococcus raffinolactis, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus brevis, three isolates of filamentous fungi (Curvularia sp., Fusarium sp. and Paecilomypasces sp.), and 39 yeasts strains. From then, 25 genera were identified, such as Cryptococcus, Candida, Sacharomyces, Trichosporon, among others, and four genera were identified using molecular techniques, including Kluyveromyces, Candida, Wickerhamiella and Rhodotorula, the latter were found at different sugarcane juice extraction points. The only yeasts that were identified at the species level were Kluyveromyces marxianus, Saccharomyces cerevisiae, and Candida tropicalis, suggesting that the juice extraction area of this cane mill could be a reservoir for new yeast speciesItem Identificación molecular de levaduras pertenecientes a la micoteca de la universidad Santiago de Cali, Colombia(Universidad Santiago de Cali, 2022) Bados López, María Camila; González Murillas, Jessica Johanna; Ramírez Castrillón, MauricioThe Mycology Research Group at Universidad Santiago de Cali has a bank of yeast strains isolated from different environments in the department of Valle del Cauca. Of a total of 285 deposited strains, only 109 had taxonomic identification at the genus and / or species level. The aim of this study was to identify yeast strains deposited in the USC fungal library, previously isolated from aquatic ecosystems and foods in Cali. For that, strains were verified according to their macroscopic and microscopic morphology and sequences of the ITS (Internal Transcribed Spacer) were obtained. In cases where ITS amplification was not obtained the D1 / D2 domain of the large ribosomal subunit (LSU) was used. The genera that were identified were: Rhodotorula, Yarrowia, Candida, Pichia, Hanseniaspora, Naganishia and Torulaspora. According to the results, the protocols used allowed enriching the identification of genera and/or species of yeasts belonging to the USC mycoteca. In addition, a new taxonomic record for Valle del Cauca (genus Naganishia) was detected, which demonstrates the importance of this type of collections for diversity in ColombiaItem In Vitro Interactions of Amphotericin B Combined with Non-antifungal Agents Against Rhodotorula mucilaginosa Strains(Springer Netherlands, 2019-01-10) Borba Spader, Tatiana; Ramírez Castrillón, Mauricio; Valente, Patricia; Hartz Alves, Sydney; Severo, Luiz CarlosRhodotorula species are emerging as opportunistic pathogens, causing catheter-associated fungemia in patients with compromised immunity. R. mucilaginosa is considered the most common species involved in human infections. Correct identification and susceptibility testing of Rhodotorula isolates recovered from the blood stream or central nervous system are essential to determine the best management of this unusual infection. The antifungal susceptibility tests showed that Rhodotorula was susceptible to low concentrations of amphotericin B (AMB) but was less susceptible to voriconazole. Combinations of AMB plus several non-antifungal medications were evaluated against 35 susceptible (Rm AMB-S) and resistant (Rm AMB-R) clinical Rhodotorula isolates using the broth microdilution checkerboard technique. We showed that in vitro exposure to increasing concentrations of AMB changed the susceptibility profile to these strains, which were named the Rm AMB-R group. The most synergistic interactions were AMB + simvastatin, followed by AMB + amlodipine and AMB + warfarin. Synergism and antagonism were observed in both groups for the combination AMB + cyclosporine A. AMB combined with a fluoroquinolone (AMB + levofloxacin) also demonstrated antagonism for the Rm AMB-S strains, but a high percentage of synergistic interactions was observed for the Rm AMB-R group. A combination drug approach can provide a different strategy to treat infections caused by AMB-resistant R. mucilaginosa.Item Levaduras oleaginosas aisladas de dos lagos de la Universidad del Valle(Universidad Santiago de Cali, 2020) Benavides León, Tatiana Andrea; Ramírez Castrillón, Mauricio; Osorio Cadavid, EstebanIn Colombia, the study of the biotechnological, microremediative, and industrial potential of the yeast community has been limited, since most of the research has only focused on species of clinical interest. Some yeasts are oleaginous by accumulating lipids between 20 to 70% of their weight, showing great potential in the biofuel and food industry. The objective of this study was to evaluate and characterize the lipid composition of yeasts previously isolated from two lakes of the Universidad del Valle. This study gravimetrically evaluated 25 yeast strains, where 52% showed oleaginous capacity with a range between 0.045 g/L and 0.598 g/L. The selected strains with lipid accumulation potential were identified at the molecular level. The Aureobasidium sp. LC112 is suggested as promising due to its high biomass production, lipid yield of 38.2% and a lipid profile with 50% saturated fatty acids, 25% monounsaturated and 25% polyunsaturated. Therefore, this strain has great potential in the biofuel, pharmaceutical, food and cosmetic industriesItem Mejoramiento de la producción de carotenoides en la cepa Rhodotorula mucilaginosa AJB01 mediante evolución adaptativa en laboratorio(Universidad Santiago de Cali, 2021) Vivas Parra, Aura Elena; Ramírez Castrillón, Mauricio; Dávalos Vélez, Andrés FelipeAdaptive laboratory evolution or evolutionary engineering, has been used for many decades to enhance critical features of industrial strains, such as carbon source utilization, tolerance to adverse environmental conditions and resistance to chemical inhibitors, due to its simplicity and effectiveness. In this investigation, an evolutionary directed experiment was carried out in order to improve total carotenoid production in R. mucilaginosa AJB01, by using an oxidative stress as the selective pressure, with increasing periodic doses of hydrogen peroxide (H2O2). The performed experiment allowed a sustained selection of higher carotenoid-producing phenotypes, surpassing the parental concentration of 170,0 mg/g in 20,1% with a total of 205,8 mg/g. This study represents the first approach in the developement of an improvement model for the production of carotenoids in yeasts belonging to Rhodotorula. Based on the achieved results, the continuation of the developed model promises a high potential in the acqusition of widely adapted higher carotenoid-producing phenotypesItem Nile Red Incubation Time Before Reading Fluorescence Greatly Influences the Yeast Neutral Lipids Quantification(2021) Ramírez Castrillón, Mauricio; Jaramillo Garcia, Victoria P.; Lopes Barros, Helio; Pegas Henriques, João A.; Stefani, Valter; Valente, PatriciaHigh-throughput screening methodologies to estimate lipid content in oleaginous yeasts use Nile red fluorescence in a given solvent and optimized excitation/emission wavelengths. However, Nile red fluorescence stabilization has been poorly analyzed, and high variability occurs when relative fluorescence is measured immediately or a few minutes after dye addition. The aim of this work was to analyze the fluorescence of Nile red at different incubation times using a variety of solvents and oleaginous/non-oleaginous yeast strains. We showed that fluorescence stabilization occurs between 20 and 30 min, depending on the strain and solvent. Therefore, we suggest that fluorescence measurements should be followed until stabilization, where Relative Fluorescence Units should be considered after stabilization for lipid content estimation.Item Riqueza de hongos asociados a la degradación de la madera en un bosque de niebla del Valle del Cauca, Colombia(Universidad Santiago de Cali, 2022) Flórez Lláñez, Danny Alexander; Ramírez Castrillón, Mauricio; Motato Vásquez, VivianaLa Cumbre, Valle del Cauca is dominated by the biome Fog forest, this type of forest hosts ecosystems of ecological importance, for which this study was conducted with the aim of identifying the fungal richness present in two studied áreas, in a fog forest that is located on the farm la Despenza, Municipality of La Cumbre, Valle del Cauca. The samples were carried out by áreas, collecting spores of wood-degrading fungi and decaying wood fragments for the subsequent isolation of yeasts. In total, 111 fungi were collected growing on live or dead wood. The laboratory obtained pure cultures of 33 macrofungi and 43 pure yeast cultures from tree bark representing a Simpson index of 0.45 reflecting a greater tendency to zero which indicates a greater richness in the forest area. The basidiomas were dehydrated and identified by their macroscopic and microscopic characteristics. Subsequently, 46 fungi were extracted and 11 of them were sequenced, either from the ITS1-5.8S-ITS2 region or the D1/D2 domain of the Large Subunit of the Ribosome (LSU). Los principales géneros identificados fueron Antrodiella, Ceriporia, Coriolopsis, Cymatoderma, Cystidiodontia, Dacryopinax, Datronia, Echinochaete, Flabellophora, Hymenochaete, Lentinus, Megasporoporia, Oudemansiella, Perenniporia, Phanerochaete, Postia y Tinctoporellus. The species Metuloidea reniformis is a new record for Colombia, both for the genus and for the speciesItem Selección de una cepa nativa de saccharomyces cerevisiae para la producción de etanol a partir de vinaza(Universidad Santiago de Cali, 2022) Basante Velasco, Angie Lizeth; Zúñiga López, Yuli Marcela; Ramírez Castrillón, Mauricio; Zambrano Salgado, Yesid FabiánVinasse comes from the distillation of fermented material in the production of ethanol. Part of the vinasse is recirculated for the fermentation tank decreasing water consumption and production costs, however, in turn it inhibits the growth of yeast. Therefore, the objective of this study was to select a native strain of Saccharomyces cerevisiae tolerant to diluted vinasse for ethanol production purposes. 23 strains of Saccharomyces spp. were evaluated, which were reactivated from the USC mycotheca, including an industrial strain and reference strains as controls. A vinasse medium supplemented with Honey B was designed, determining the concentration of total reducing sugars and volatile acidity, performing fermentations under conditions of oxygen restriction, ambient temperature and constant agitation. Three strains of S. cerevisiae were preselected for their alcohol-producing capacity in synthetic medium, although only the LC010-A strain was evaluated for further experiments. Alcohol concentrations were 6.7% v/v for S. cerevisiae LC010-A and 4.5% v/v for S. cerevisiae NCYC 660 (internal code RNC.1). Yeast strains are usually tolerant to the toxic components of vinasse, when the levels of these acids are less than 3000 ppm approximately, since if this range is exceeded it leads to low yields, and even the inactivation of the yeast. Therefore, these yeasts, especially S. cerevisiae LC010-A, showed tolerance by fermenting substrates containing vinasse and inhibitors, highlighting the potential use of strains native to Valle del CaucaItem South Brazilian wines: culturable yeasts associated to bottled wines produced in Rio Grande do Sul and Santa Catarina(Springer Netherlands, 2017-03-24) Ramírez Castrillón, Mauricio; Camargo Mendes, Sandra Denise; Valente, PatriciaA comprehensive understanding of the presence and role of yeasts in bottled wines helps to know and control the organoleptic quality of the final product. The South Region of Brazil is an important wine producer, and the state of “Rio Grande do Sul” (RS) accounts for 90% of Brazilian wines. The state of “Santa Catarina” (SC) started the production in 1975, and is currently the fifth Brazilian producer. As there is little information about yeasts present in Brazilian wines, our main objective was to assess the composition of culturable yeasts associated to bottled wines produced in RS and SC, South of Brazil. We sampled 20 RS and 29 SC bottled wines produced between 2003 and 2011, and we isolated culturable yeasts in non-selective agar plates. We identified all isolates by sequencing of the D1/D2 domain of LSU rDNA or ITS1-5.8 S-ITS2 region, and comparison with type strain sequences deposited in GenBank database. Six yeast species were shared in the final product in both regions. We obtained two spoilage yeast profiles: RS with Zygosaccharomyces bailii and Pichia membranifaciens (Dekkera bruxellensis was found only in specific table wines); and SC with Dekkera bruxellensis and Pichia manshurica. Knowledge concerning the different spoilage profiles is important for winemaking practices in both regions.Item Water Quality, Heavy Metals, and Antifungal Susceptibility to Fluconazole of Yeasts from Water Systems(Multidisciplinary Digital Publishing Institute (MDPI), 2023-02) Caicedo Bejarano, Luz Dary; Osorio Vanegas, Lizeth Stefania; Ramírez Castrillón, Mauricio; Castillo, Jorge Enrique; Martínez Garay, Carlos Andrés; Chávez Vivas, MónicaAquatic environments could be reservoirs of pathogenic yeasts with acquired antifungal resistance. The susceptibility to antifungal agents of yeasts present in the wastewater and natural waters of the city of Cali was evaluated. Samples were taken from two types of water: drinking water (Meléndez River, drinking water treatment plant “Puerto Mallarino” in the Cauca River) and wastewater (South Channel of the Cauca River, “Cañaveralejo-PTAR” wastewater treatment plant). Physico-chemical parameters, heavy metal concentration, and yeast levels were determined using standard procedures. Yeasts were identified using API 20 C AUX (BioMérieux) and sequence analysis of the ITS1-5.8S-ITS2 and D1/D2 regions of the large subunit of the ribosome. Susceptibility assays against fluconazole and amphotericin B using the minimum inhibitory concentration (MIC) test were determined using the microdilution method. The influence of physico-chemical parameters and heavy metals was established using principal component analysis (PCA). Yeast counts were higher at WWTP “PTAR” and lower at Melendez River, as expected. A total of 14 genera and 21 yeast species was identified, and the genus Candida was present at all locations. Susceptibility tests showed a 32.7% resistance profile to fluconazole in the order DWTP “Puerto Mallarino = WWTP “PTAR” > South Channel “Navarro”.