Browsing by Author "Ramírez Castrillón, Mauricio (Director)"
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Item Actividad enzimática de levaduras recolectadas de diferentes ambientes del Valle del Cauca(Universidad Santiago de Cali, 2020) Olaya Hurtado, Dora Stefany; Ossa Cabra, Liseth Tatiana; Martínez Garay, Carlos Andrés (Director); Ramírez Castrillón, Mauricio (Director)Agro-industrial waste affects the environment, which makes it a current problem. A sustainable strategy is the use of microorganisms, such as yeast, to metabolize and to degrade these compounds, which will allow the development of bioremediation strategies. In this research, we tested yeasts from the mycoteca of Universidad Santiago de Cali, collected from different environments of Valle del Cauca, to determine their enzymatic activity. For this, they were grown in media with different substrates, to evaluate their ability to degrade them through the determination of an enzymatic coefficient (PZ), which takes into account the degradation halos formed. A total of 95 yeast strains were evaluated, of which 37 strains presented some enzymatic activity. Several strains showed potential in this field; the LN6A, P4, LC071A, YAM1, and YAM3 strains had the highest enzymatic activity; while some had the ability to degrade or metabolize two different substrates (LN4A, MRC33, LC112, P4, LN7C) or up to three types of substrate (MRC39). In addition to this, the LN4A strain, from the Navarro lagoon and identified as Candida tropicalis, presented a higher enzymatic activity in two types of substrate.Item Catálogo de levaduras en Colombia: Revisión sistemática(Universidad Santiago de Cali, 2021) Barona Colorado, Anabel; Bolaños Burbano, Dahyana (Directora); Ramírez Castrillón, Mauricio (Director)The diversity of fungi in Colombia is not well known, where there are at least 7,273 species, a low number when compared to other countries. Yeasts have been little explored and little is known about their sampling effort. Therefore, this work aimed to review all the publications studies of repositories, databases, and public collections reporting the isolation and identification of environmental yeasts in Colombia from the years 2000 to 2020. All clinical isolates (human or related to zoonotic diseases) were excluded. 112 species of environmental yeasts occurring in four regions and 11 departments of Colombia were found, with 73.4% of yeasts belonging to Ascomycota and 26.6% to Basidiomycota. The most common primary environments were associated with different parts of plants, soils, and animals. Secondary environments with the reported yeasts were fermented fruits and fermented beverages. The most representative species were Cryptococcus neoformans (544 strains), Cryptococcus vini (360), and Cryptococcus gattii (243).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 (Directora); Ramírez Castrillón, Mauricio (Director)The 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 fungus.Item Efecto del estrés celular en la producción de pigmentos en la cepa Rhodotorula mucilaginosa/alborubescens AJB01 aislada en el Caribe Colombiano(Universidad Santiago de Cali, 2020) García Cortés, Alejandra; García Vásquez, Julián Andrés; Ramírez Castrillón, Mauricio (Director); Aranguren Díaz, Yani Cristina (Directora)Most of the dyes or pigments used in the industry are toxic and potentially mutagenic, with some carcinogenic effects, so their replacement and disposal of industrial effluents is a priority task. Therefore, searching microbial bio-pigments is of great interest in the industry. The objective of this work was to obtain the overproduction of carotenoid pigments in a naturally pigmented yeast through the application of different sources of cellular stress. The strain AJB01 was isolated from a sample of food obtained in Barranquilla, Colombia and its main pigment is 𝛽-Carotene. This strain was subjected to different conditions, such as osmotic stress with different salts, physical stress from exposure to UV light and light stress from exposure to different photoperiods. The best culture conditions for obtaining carotenoids were: one minute of ultraviolet light, 0.5 mg/L of magnesium sulfate and 18:6 hours of photoperiod, respectively, generating a yield of 118,33 µg/g carotenoids.Item Evaluación de la producción de carotenoides en levaduras nativas aisladas de la ciudad de Cali(Universidad Santiago de Cali, 2020) Villota Cobo, Sandra Viviana; Ramírez Castrillón, Mauricio (Director); Martínez Garay, Carlos Andrés (Codirector)In this study, the carotenoid production capacity in native yeasts isolated from the city of Cali was evaluated. 30 yeasts were selected, each of them was seeded in duplicate in MSS (solid pigment inducing medium), they were incubated for 5 days at room temperature (25°C). Pigments were extracted from the biomass obtained for characterization by HPLC. They were identified with molecular techniques and the CS13, P10A and P11A strains were made growth kinetics. The highest yield in pigment extraction was obtained by the CS13 strains with 10.2 µg / mL, the P10A strain with 9.7 µg / mL and the P11A strain with 7.5 µg / mL concentration for β-carotene. The kinetics of growth and pigment production during five days was optimal for the P11A strain, from 48 hours its concentration was 109.62 µg / mL and 1403.10 µg / mL at 120 hours of total carotenoids. In this study, it was found that yeasts isolated from aquatic systems are promising for the production of carotenoid pigments (including β-carotene), making their extraction and characterization viable for future biotechnological studies.Item Susceptibilidad a los antimicóticos de levaduras aisladas de los sistemas de aguas de la ciudad de Santiago de Cali, Colombia(Universidad Santiago de Cali, 2019) Osorio Vanegas, Lizeth Stefania; Caicedo Bejarano, Luz Dary (Directora); Ramírez Castrillón, Mauricio (Director)Fungal infections increased markedly on the world. Currently, new pathogenic yeast species are reported with more frequence. The most important sources of aquatic isolation are industrial and municipal wastewaters, represented by chemical, physical and biological pollutants. The aim of this study was to characterize the antifungal susceptibility of yeasts isolated from, water systems in Cali, Colombia. Also to assens the correlation between physicochemical parameters, heavy metals, and fluconazole susceptibility, one of the most used antifungal. Two types of water were collected: potable (Río Meléndez, Puerto Mallarino) and residual wastewaters (Canal Sur, Planta de Tratamiento Cañaveralejo - PTAR). Serial dilutions were made and the samples were cultured on Dicloran Rose Bengal Chloramphenicol (DRBC) agar (Merck) and CHRomagarCandida (BBL) to count the CFU/mL. Study of susceptibility to Amphotericin and Fluconazole were made by the plate microdilution technique. Groupings were carried out according to their morphology and the identification of the representative isolates of each morphotype was carried out by biochemical kit (API 20C) and analysis of sequences of the ITS1-5.8S-IST2 region. 15 yeast species were identified with API 20C and six species by molecular biology corresponding to: Candida albicans, Pichia fermentans, Diutina catenulata, Rhodotorula mucilaginosa, Trichosporon coremiiforme and Pichia kluyveri. It was reported two morphotypes corresponding to new species of Candida.