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Evaluación de bacterias potencialmente degradadoras de polietileno de baja densidad (LDPE)
(Universidad Santiago de Cali, 2022) Vidal Arango, Karen Johana; Bomba Ospina, María Isabel; Álzate Calderón, Paola
Low-density polyethylene (LDPE) is a material used to wrap products and to produce packaging. The prolonged use of this material and the inadequate management of the waste generated contribute to the environmental contamination of the planet. The objective of the present study is to find at least one bacterium potentially degrading LDPE-type plastic. The strains were randomly selected, reactivated in nutrient agar by depletion seeding and in vitro assays were carried out with the study material for approximately six months. The plastics used as matrix to evaluate degradation were from the packaging of the following commercial brands: Rendy (toilet paper), Mercamio (bread), Familia (napkins), Diana (rice), Control (ziploc). The results obtained showed that there was an important deterioration in the plastics of the Rendy brand, where 24,0% degradation was evidenced. Gram staining and sowing in the selective media Agar Bacillus and Agar Cetrimide verified the growth of colonies with the typical morphology for each culture medium. Finally, an analysis was carried out in the TEMPO® equipment to identify the bacteria with the greatest degradation potential, which yielded the microorganism Bacillus cereus as the greatest degrader of plastic. It is concluded that this study is of vital importance since it contributes with an alternative that would allow reducing the contamination caused by petroleum-derived plastics and opens doors for future research in the area, where it is expected that more microorganisms with great degradation potential can be found
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, Mauricio
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
Hongos Micotoxigénicos presentes en Maní procesados de manera Artesanal e Industrial en la ciudad de Cali
(Universidad Santiago de Cali, 2022) Garzón Ruiz, Sebastián; Vélez Castaño, Ronald Alexis; Caicedo Vejarano, Luz Dary; Martínez Garay, Carlos Andrés
The peanut (Arachis hypogaea) is a nut with high nutritional value that makes it an ideal substrate for fungal growth and mycotoxin contamination. This study determined the presence of fungi with mycotoxigenic potential in artisanal, industrial, and raw processed peanuts from stores and supermarkets in the city of Santiago de Cali. A total of 204 peanut samples were analyzed, 60 raw, 60 industrial and 84 artisanal. The percentage of contamination was measured with the direct plating method on DRBC agar and the qualitative analysis of aflatoxins with Coco agar. In this study, 1824 isolates were made with a contamination percentage of 77.4%, 12.45% and 10.14% for raw, industrial, and artisanal peanuts, respectively. The genera Aspergillus, Penicillium and Rhizopus occurred most frequently. It was found that 22 out of 31 strains of Aspergillus section Flavi were positive for the qualitative aflatoxin test
Dermatofitos en suelos de parques y entidades educativas de la zona urbana y rural de Santiago de Cali, Colombia
(Universidad Santiago de Cali, 2022) Ordóñez Gordillo, Daniel Felipe; Calvache Jaramillo, Luis Miguel
Dermatophyte fungi are pathogenic for humans and animals, generating a public health and veterinary problem at local, national, and international levels, especially affecting children in tropical areas. This study determined the presence of dermatophyte fungi in soils of parks, schools, and kindergartens in rural and urban areas of the city of Santiago de Cali, Colombia. The hair bait technique by Vanbreuseghem was used for this study. A total of 270 soil samples were analyzed, 218 from the urban area and fifty-two from the rural area of the city of Santiago de Cali: 152 corresponded to parks and 118 to educational institutions. Of the samples analyzed, only one dermatophyte fungus was found, the Nannizia gypsea complex, with 141 positive samples corresponding to 52.2%. In the urban area 114/218 (52.3%) and the rural area 27/52 (51.9%) were positive for this fungus, without finding statistical differences between these two areas. In parks 94/152 (61.8%) and educational entities 47/118 (39.8%) were positive with a significant p value. Different physicochemical parameters of the soil were analyzed and only association of the presence of the dermatophyte fungus with pH was found. Other keratinolytic fungi found were Fusarium sp; Aspergillus sp; Chrysosporium sp. among others
Análisis comparativo de tres métodos biológicos en el tratamiento de vinazas
(Universidad Santiago de Cali, 2022) Ruiz León, Nathalia; Jaramillo Castaño, Nicolás; Pérez Mora, Lina Susana
The purpose of the systematic review of the literature published between 2012 and 2021 is to evaluate the different alternative treatments for the purification of vinasse focused on three biological methods: anaerobic treatment, composting, and cultivation with microalgae. To this end, an analysis of various scientific articles and studies were carried out in different institutional and academic platforms in Spanish and English. It was identified that, in the three processes studied, they all have an application history that verifies their usefulness in reducing the aforementioned contaminants. They can be compared for their efficiency, operating conditions, level of removal, and time required in their transformation and depending on the circumstances the best alternative can be chosen. The anaerobic method is the most effective with an 80% reduction in organic load, but with a medium level of difficulty in its operation and a necessary transformation time of 60 days. While the composting method presents the lowest operating costs, a reduction of organic load of 68%, with a longer transformation time of 240 days. Finally, the microalgae culture method handles the shortest transformation time in 10 days to reach a contaminant reduction level of 50% but with high operating costs