Microbiología
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Item Caracterización microbiológica y molecular de transconjugantes obtenidos a partir de aislados de Escherichia coli resistentes a cefalosporinas provenientes de la ciudad de Cusco, Perú(Universidad Santiago de Cali, 2025) Martinez Arroyabe, Daniela; Correa Bermúdez, Adriana; Falco Restrepo , Aura DayanaEscherichia coli (E. coli) is a gram-negative, facultative anaerobic bacillus that lives in the intestines of warm-blooded animals and in the environment. In recent years, there has been a worldwide increase in resistance to beta-lactam antibiotics, especially third-generation cephalosporins. This increase has been reported to be associated with the horizontal transfer of the plasmid genes blaTEM, blaSHV, and blaCTX-M, through the process of conjugation, which represents an epidemiological risk to global public health. The frequency of third-generation cephalosporin-resistant E. coli isolates is high in Latin American countries, including Peru. In a previous study, transconjugants of cephalosporin-resistant E. coli isolates from Cusco, Peru, were obtained; however, the genes transferred by conjugation were not characterized. Therefore, in this study, the microbiological and molecular characterization of E. coli transconjugants obtained from third-generation cephalosporin-resistant isolates from Cusco was performed. This allowed us to detect the presence of the blaTEM gene in 7.1% and the blaCTX-M gene in 64.2% of the strains evaluated, with 36% of genes unidentified. In addition, the antibiotic sensitivity profiles of the transconjugants were determined, identifying that 85.71% of the transconjugants showed changes in the MIC with respect to E. coli J53. Based on the results obtained, the implementation of guidelines regarding the donor strain is recommended. These results show that the plasmid conjugation process of E. coli carrying BLEE is more efficient with CTX-M than with other genes, which is associated with the widespread dissemination of this enzyme worldwideItem Caracterización de la capacidad lignolitica de bacterias presentes en el proceso de compostaje en el ingenio Incauca(Universidad Santiago de Cali, 2025) Arce Vargas, Nelson Antonio; Jaimes Loaiza, Danna Isabella; Fernández Daza, Fabian Felipe; Diaz Caicedo, Lizeth NataliaObjective: To characterize bacterial strains with ligninolytic capacity present in the composting process of The Incauca sugar mill. Methodology: Lignin was extracted from sugarcane bagasse and leaves using the Kraft method. Bacteria were isolated from nine 300 g samples collected from bagasse piles, material in process, and compost. Serial decimal dilutions were plated on MMS agar (minimal salt medium) supplemented with 5 mL of lignin. Colonies with the highest growth were selected, followed by Gram staining and species identification using the VITEK®2 system. Ligninolytic capacity was assessed by UV-Vis spectrophotometry at 260 nm. Results: A total of 18 bacterial isolates were obtained: 4 from bagasse, 6 from material in process, and 7 from compost. Of these, 76.5% were Gram-positive, exhibiting bacillus and coccus morphologies. Five isolates were identified as Enterobacter cloacae complex (n = 3) and Klebsiella pneumoniae (n = 2). The Enterobacter isolates showed higher lignin degradation, with transmittance values ranging from 0.038 to 0.041. Conclusion: Composting serves as a viable source for isolating ligninolytic bacterial species, which are characterized by their ability to colonize organic matter and environmental substratesItem Prevalencia y caracterización molecular de Staphylococcus pseudintermedius resistente a meticilina (MRSP) mediante detección del gen meca en animales domésticos: Una revisión sistemátic(Universidad Santiago de Cali, 2025) Prieto Durán, Sandra; Fernández Daza, Fabian FelipeThis systematic review analyzes the prevalence and molecular characterization of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in domestic animals through the detection of the mecA gene as the main resistance marker. A total of 50 studies published between 2015 and 2025 were examined, retrieved from reputable databases such as PubMed, Scopus, and Web of Science, following PRISMA guidelines. The results reveal high variability in MRSP prevalence, with rates ranging from 0.2% to 100%, depending on country, species, and clinical setting. Brazil, Germany, and the United States reported the highest number of studies. The mecA gene was detected in 100% of MRSP strains in several studies and was frequently associated with resistance to multiple antibiotic classes, particularly β-lactams, macrolides, aminoglycosides, and fluoroquinolones. Molecular techniques, especially PCR, demonstrated high sensitivity and specificity for mecA detection, while the ST71 lineage was the most commonly identified worldwide. A significant link was found between prior antimicrobial use and the emergence of resistant strains. These findings highlight the need to strengthen epidemiological surveillance systems, optimize diagnostic methods, and promote the rational use of antibiotics in veterinary medicine as a control measure against the spread of multidrug-resistant pathogens with zoonotic potentialItem Epidemiología de H. pylori en Latinoamérica y su relación con el cáncer gástrico: Una revisión sistemática.(Universidad Santiago de Cali, 2025) Carabali Velasco, Karold Vanessa; Gafaro Montejo, AlexisH. pylori is a bacterium that colonizes the gastric tract of more than 50% of the world's population. It is characterized as a factor that predisposes individuals to develop gastric cancer through various virulence and pathogenicity mechanisms. Latin America represents one of the regions with the highest prevalence of this bacterium and gastric cancer; therefore, the present study focused on analyzing the distribution of H. pylori and its influence on the development of gastric cancer in Latin America, considering socioeconomic, environmental, and genetic risk factors. A bibliographic search was conducted in 5 databases, including ScienceDirect and Springer Link, obtaining a total of 454 articles, of which 50 met the inclusion criteria. These studies reported variable prevalences of H. pylori infection in Brazil, Argentina, Chile, Colombia, Honduras, and Cuba, with percentages ranging from 5% to 91%. In turn, gastric cancer incidences were found in Peru (15.2/100,000), Chile (13.1/100,000), Costa Rica, and Colombia (12.8/100,000). Furthermore, the virulence genes cagA and vacA were observed in the majority of positive cases of bacterial infection, establishing a positive relationship with cancer development. However, genetic factors and unhealthy lifestyles also strongly influenced the development of the disease. It is important to conduct similar analyses in other high-risk regions to allow comparison of the results obtained in this studyItem Caracterización del microbioma presente en la producción de vino de uva artesanal en Costa Rica, Ginebra, Valle del Cauca(Universidad Santiago de Cali, 2025) Rivera Quiñones, Angela Valentina; Fernández Daza, Fabian Felipe; Cuervo Mulet , Raúl AlbertoWine is a fermented beverage produced worldwide. In Colombia, the municipality of Ginebra, Valle del Cauca, is recognized for its semi-industrial and artisanal wine production, the latter being closely associated with the socioeconomic development of the community. However, these artisanal processes are not standardized, often resulting in flavor alterations. For this reason, a characterization of the microbiome present throughout the four stages of wine production was carried out, with the aim of generating training strategies to improve product quality and strengthen its market positioning. Samples were taken from the must, alcoholic fermentation, malolactic fermentation, and bottling stages. These were cultured using serial dilution up to 10⁻³ on GYC, MRS, DRBCA, and PDA agar media. Identification was performed through DNA sequencing and biochemical characterization of yeasts using the Pitt and Hocking key, which evaluates nutrient assimilation (urea, malt, arabinose, maltose, maltose-glucose, lactose, glucose, mannitol, xylose, and nitrate). Additionally, a flavor analysis was conducted by expert personnel to guide training efforts. Results showed that alcoholic fermentation was efficient, with a residual sugar content of 40 g/L. However, malolactic fermentation was incomplete, as the sensory profile revealed a high concentration of acetic acid, mainly attributed to Acetobacter pasteurianus. Despite this, the presence of Lactobacillus delbrueckii, Torulaspora delbrueckii, Streptococcus thermophilus, Hanseniaspora uvarum, Kluyveromyces lactis, and Saccharomyces cerevisiae contributed to the wine’s body, freshness, and fruity aromas, derived from esters, isoamyl acetate, exopolysaccharides, and other volatile compounds. These characteristics make this artisanal red wine a high-quality product representative of the Ginebra, Valle del Cauca regionItem Validación del método de muestreo de superficies por la técnica de contacto e hisopado (frotis) en la planta farmacéutica de Sanofi ubicada en la ciudad de Cali(Universidad Santiago de Cali, 2023) Sabogal Girón, Natalia Jhaidiris; Vargas Vargas, Juan José; Luengas Olave, Francy Soraya; Falco Restrepo, AuraThe objective of the research is to validate the surface sampling method by the contact and swab technique (smear) in the Sanofi pharmaceutical plant located in the city of Cali. The methodology was experimental, analyt-ical, microorganisms were used with ATCC certification. The results allowed to conclude that the results of the validation of the surface sampling technique showed that both techniques allowed the recovery of specific test organisms present at different sampling points that constituted the environmental monitoring program does not present statistically significant differences and trends , so both methods can be used for general monitoring of surface pollution in the plantItem Determinación de la actividad proteolítica y lipolítica de hongos filamentosos.(Universidad Santiago de Cali, 2023) Campos Nuñez, Diego Fernando; Gonzales Vargas, Iván Andrés; Fernández Daza, Fabian FelipeFungi, like living beings, are heterotrophic organisms. Throughout their evolution, fungi have developed survival strategies whose distribution extends in practically all ecosystems of our planet. The body of fungi is composed of filaments called hyphae, which bifurcate repeatedly to form networks or mycelia that grow on and within all types of living or inert organic materials, the hyphae through their walls secrete enzymes such as chitinases, proteases and lipases. In this study, proteolytic and lipolytic activity was evaluated in 70 filamentous fungi obtained from soils. Three agar preparations with different components were analyzed for each of the activities evaluated in order to determine which of them showed better resolution of the enzymatic activities. For the proteolytic activity, medium number two was used and for the lipolytic activity, medium number one was used since these allowed a better visualization of the halos. As a criterion for the evaluation of the enzymatic activity, the result was identified with the formation of hydrolysis halos around the fungus. The results showed that of the 70 fungi evaluated, 6 main genera were found which are Penicillium sp, Aspergillus sp, Geotrichum sp, Trichoderma sp, Fusarium sp, Trichosporon sp of which the genus Aspergillus sp was the fungus that had the highest prevalence in the tests of exclusively proteolytic activity as was the fungus 39-39, exclusively lipolytic represented by fungus N4 and also the genus that obtained the highest prevalence among the fungi that tested positive in both activities were fungi -12 for proteases and fungus 32LP4. These fungi can be selected for future enzyme kinetics analysis to be used as possible entomopathogenic fungiItem Evaluación de la actividad larvicida de Trichoderma harzianum y Bacillus thuringiensis sobre el gusano barrenador de la caña de azúcar Diatraea saccharalis.(Universidad Santiago de Cali, 2023) Ayala Ortega, Mabel Andrea; Perea, Esteban Murcia; Martínez Garay, Carlos AndrésThe pests present in crops are one of the biggest problems, which results in economic losses and possible diseases to the consumer. The larva of Diatraea saccharalis is identified as the main problem for sugarcane producers in Valle del Cauca, causing weight loss and sugars in the stem when the cane is ripe. The damage caused to the plant facilitates fungal and/or bacterial infections. For this reason, it is proposed to evaluate the bioinsecticidal activity of the bacterium Bacillus thuringiensis and the fungus Trichoderma harzianum on the larvae of the sugarcane borer Diatraea saccharalis. Three treatments (1x108 esp/mL, 1.25x106 esp/mL, 2x105 esp/mL) were evaluated for T. harzianum and two for B. thuringiensis (1x109 CFU/mL and 1x106 CFU/mL) in triplicate using 60 larvae for each treatment. Therefore, treatment 1 (1x108 esp/mL) of the fungus T. harzianum presented a mortality of 52.83% in 204 hours (8.5 days) and treatment 2 (1.25x106 esp/mL) a mortality of 37.74%, without showing a significant difference between the two treatments. Treatment 1 (1x109 CFU/mL) of B. thuringiensis presented a mortality rate of 96.23% at the same time. The results showed that Trichoderma harzianum does have an effect on the mortality of D. saccharalis larvae. when applied at a concentration of 1x108 esp/mL, but it is not as efficient compared to B. thuringiensisItem Síntesis de nanopartículas poliméricas asociadas a imipenem para enfrentar la multidrogorresistencia frente a la bacteria Klebsiella pneumoniae productora de carbapenemasas tipo KPC(Universidad Santiago de Cali, 2023) Bautista Rincón, Angibet; Chalarca Salazar, Angie Yuliet; Oñate Garzón, José Fernando; Rivera, Sandra PatriciaKlebsiella pneumoniae is a Gram negative bacterium and is the main Enterobacterium isolated in hospital infections, since it plays an important role in nosocomial diseases. Klebsiella pneumoniae is becoming a public health problem worldwide because it has a type of enzyme called KPC-type carbapenemase that gives the bacteria resistance to carbapenem drugs such as Imipenem, Meropenem, Ertapenem and Doripenem. Imipenem is an antibiotic that is supplied in combination with another drug called cilastatin, which helps to prolong the effect of imipenem by protecting it from breakdown when ingested [1], however, the administration of this type of drug generates side effects. in patients becoming nephrotoxic. One of the promising strategies to combat resistant bacteria, decrease the rate of morbidity and mortality from nosocomial infections, and reduce the side effects generated by the administration of certain antibiotics, is the use of antibiotic-loaded chitosan nanoparticles. Chitosan is a biopolymer that is obtained from the partial deacetylation of chitin which is present in the exoskeleton of crustaceans. Due to the high biocompatibility of chitosan, it is currently used as a material for the production of nanoparticles. Chitosan nanoparticles have high potential for the loading, transport and controlled release of molecules [2]. The purpose of this study is to develop polymeric chitosan nanoparticles associated with imipenem to face the bacterial resistance of Klebsiella pneumoniae. The method consists of the production and characterization of highly deacetylated chitosan and imipenem-loaded chitosan nanoparticles obtained by ionic gelation assisted by high intensity sonication. These nanoparticles were analyzed and characterized in terms of particle size, Polydispersity Index, Potential Zeta (PZ) and encapsulation efficiency. Its antimicrobial activity was evaluated using the broth microdilution method according to the Clinical & Laboratory Standards Institute (CLSI) using carbapenem-sensitive and resistant Klebsiella pneumoniae strains. As a result, a particle size < 500 nm, positive Zeta potential values and a stable polydispersity index with values between 0.07 and 0.2 were obtained, obtaining a monodisperse population. The reported results were promising for Klebsiella pneumoniae demonstrating that imipenem-loaded chitosan nanosystems provided antibacterial efficacy compared to free imipenem against Gram-negative bacteria resistant to this antibioticItem Estudio morfológico, estructural y microbiológico de películas delgadas de Ti-Ag para implantes dentales(Universidad Santiago de Cali, 2023) Plaza Velasco, Natalia; Ramírez Calero, María Camila; Acosta, Franklin Bermeo; Garcés Constaín, Paula AndreaThe search for materials to produce dental implants has been of great interest in the fields of medicine, chemistry and biology. Generally, implants have complications due to bacterial infections or incompatibility with the human body, therefore titanium and silver stand out with great relevance due to their great capacities for harmlessness and coupling with the human body. The results of this study contributed to the investigation of what the ideal thicknesses of titanium and silver could be for the manufacture of thin films in order to make dental implants with greater antimicrobial activity. The films were structurally characterized, confirming the presence of Silver and Titanium; morphologically the roughness was characterized; The surface energy was characterized, the wettability analysis revealed that the contact angles were less than 90º, which corresponds to hydrophilic surfaces.. On the other hand, the antimicrobial activity was evaluated against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans where the results obtained demonstrated that Ti/Ag thin films with Ti thicknesses of 180nm and 360nm have promising antimicrobial properties for dental coatings, inhibiting the adhesion of biofilms in P. aeruginosa (100%), S. aureus (100% and 96%) and C. albicans (80% and 90%) respectively, these responses are related to roughness and reflect different responses for bacteria and yeastItem Validación de método microbiológico cilindro en placa para determinación de la potencia de neomicina en producto farmacéutico triconjugado crema (neomicina, clotrimazol y betametasona)(Universidad Santiago de Cali, 2023) Álzate González, Diego Alejandro; Rivera Sánchez, Sandra Patricia; Cruz Bolaños, Yimi WilliamThe finished product Betamethasone, clotrimazole, neomician cream, is manufactured for sale and export to the main countries of the world, such as: Mexico, the western part of South America, Ecuador, Peru and India. The determination of the potency of neomycin with the cylinder plate method allows demonstrating the effectiveness of the methodology, and can be used as a quality control method, in the plant located in the industrial zone of the city of Cali. The present work was carried out at the pharmaceutical company Lafrancol S.A.S plant Cali, where the challenge organism used in each stage of the process was evaluated, respectively the ATCC 12228 S. epidermidis strain. The stages of the process were: a) standardization of the inoculum, b) productivity tests of the culture media, c) development of the validation technique for the cylinder-in-plate microbiological method for the determination of neomycin potency. During the validation process, the comparison of the results obtained by two observers was included, demonstrating that the reproducibility complies, since the data shows that the coefficient of variation between each repetition with the different results of the standard and inoculum analyzed are less than 10 % being very homogeneous; Regarding accuracy, it was evidenced with the correlation coefficient of concordance between the counts of the observers, very consistent results were found. The effectiveness of the validation of the method was demonstrated, for the different stages of selectivity, which only evidenced the degradation of less than 70 % of the neomycin molecule in the acid conditionItem Revisión sistemática sobre la producción de biodiésel a partir de microorganismos oleaginosos en Latinoamérica con énfasis en Colombia(Universidad Santiago de Cali, 2023) Quiñones Aguirre, Lina Natalia; Álzate Calderón, Paola; Mellizo, Jhon EricCurrently, the production of biodiesel is considered the best alternative to reduce among other things the environmental impacts caused in the production and use of fossil fuels, the use of oily microorganisms as a raw material to produce biodiesel triggers great interest because it has great advantages compared to other types of raw materials, among these the reduction of production costs. That is why we proposed the elaboration of a systematic review of the existing literature during the period 2008-2022 on studies related to the production of biodiesel from oilseed microorganisms in the most representative countries of Latin America (Brazil, Argentina, Colombia, Peru, Ecuador, Mexico, and Chile). For this, a search log was prepared in which databases of gray literature type, specialized and multidisciplinary are included. The data were analyzed according to some of the parameters recommended by the PRISMA Declaration. In total, 70 publications were included, finding that the type of microorganism most used in the different studies were Microalgae (53) and that the country with the most reports for the different microorganisms was Brazil (31), as well as relevant information such as lipid productivity, biomass and fatty acids according to the information provided in the different studies for each case It is expected that this review will strengthen the studies for the production of biodiesel using oilseed microorganisms as raw material in Colombia, providing consolidated and relevant information so that the scientific community can develop related studies and promote the use of microorganisms at an industrial and biotechnological levelItem Degradación del polietileno de baja densidad mediada por hongos filamentosos: Una revisión sistemática(Universidad Santiago de Cali, 2023) Banguera Ortiz , Adriana Sofia; Rangel Hoyos, Patricia; Rojas Barreto, Julián Alonso; Caicedo Bejarano, Luz DaryLow-density polyethylene (LDPE), is used in the food, clothing, transportation, construction, and medical industries. It is a high-consumption material and due to its physicochemical nature is extremely durable, recalcitrant, relatively unbreakable, and could be present for more than 50 years in the environment. Their accumulation generates serious pollution damage affecting natural resources, threatening fauna, wildlife, and even public health. In most landfills plastic waste represents the largest fraction, reaching up to 25% by weight in some sites. Degradation of LDPE can occur by chemical, physical, and biological methods, which can be affected by temperature, UV light, and enzymatic actions of both bacterial and fungal microorganisms. In biodegradation studies, fungi are considered potential candidates for LDPE degradation, due to their ability to adhere to the polymer surface and the production of intra- and extracellular enzymes. This review reports fungi isolated from LDPE-rich landfills with LDPE biodegradative capacity. Some fungi reported were of the genus Aspergillus, Penicillium, Rhizopus, among others. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques are used to measure biodegradation and although other reviews have been analyzed, there is little information on fungi extracted from landfills used for LDPE biodegradationItem Evaluación de la actividad antimicrobiana de colistina encapsulada en nanopartículas de quitosano frente a bacterias extremadamente drogo resistentes(Universidad Santiago de Cali, 2023) Barrera Vélez, Alejandro-Programa Química Farmacéutica ; Pacheco Sierra, Fabian Alexander-Programa Microbiología; Oñate Garzón, José Fernando; Polo Cerón, DorianAntibiotics are a crucial tool in the fight against bacterial infections, both in humans and animals. However, inappropriate use of these drugs has led to bacteria adapting and developing resistance to them, as is the case of P. aeruginosa bacteria, which has multiple ways of resisting even last-line antibiotics, such as colistin. This antimicrobial polypeptide is effective against gram-negative bacteria, but it has nephrotoxic side effects and its efficacy is decreasing against P. aeruginosa. To address this global problem, new techniques have been developed to improve the antimicrobial activity of existing antibiotics. One such technique is the encapsulation of colistin in a natural polymer called chitosan, which improves drug dispersion and increases its activity against bacteria. Recent studies evaluated the performance of chitosan nanoparticles loaded with antibiotics to treat bacterial resistance. The results indicated a significant decrease in bacterial antimicrobial activity, suggesting that the chitosan encapsulation technique could be a promising alternative for the treatment of antibiotic-resistant bacterial infections. To determine this, the performance of chitosan nanoparticles loaded with colistin was synthesized, characterized and evaluated against 2 strains of P. aeruginosa, one sensitive and the other extremely resistant to colistin; obtaining as a result a decrease in the microbial activity (going from growth at colistin concentration of 16 µ/mL to 4 µ/mL) of extremely resistant P. aeruginosaItem Contribución antimicrobiana de colistina encapsulada en liposomas recubiertos con Quitosano de alto peso molecular (QHPM) frente a bacterias Gram negativas(Universidad Santiago de Cali, 2023) Cardona Hoyos, Ana Sofía; Salazar Guerra, Mayra Alejandra; Oñate Garzón, José Fernando; Ciro, YhorsPseudomonas aeruginosa is a Gram negative bacterium, which is not considered part of the human microbiota, so it has the ability to adapt to different environmental conditions due to its intrinsic resistance mechanisms to different antibiotics. This pathogen can colonize hospital environments, such as mechanical ventilators, catheters, among others. P. aeruginosa is of great importance worldwide as it is the main pathogen that causes infections in intensive care unit (ICU) patients. This makes it a public health problem since it has shown resistance to antibiotics such as colistin. The purpose of this study is to develop nanoliposomes functionalized with colistin-containing polymers to address the bacterial resistance of Pseudomonas aeruginosa. The method consists of the encapsulation of colistin within nanoliposomes superficially modified with high molecular weight chitosan (QHPM) to subsequently perform physicochemical characterization of the liposomes, where the particle size and zeta potential will be determined using a Zetasizer nano ZSP; The liposomes were characterized using dynamic light scattering and zeta potential where both parameters were observed to fluctuate in relation to polymer coating. Finally, the antimicrobial activity of colistin transported within the nanosystems was evaluated. Which the registered results were promising against isolated resistant Pseudomonas aeruginosa since it was possible to obtain a decrease in the MIC from 4 µg/mL to 2 µg/mL. However, more research is needed to determine the safety and efficacy of this strategy in humansItem Exploración de la selectividad de colistina hacía Escherichia coli y de daptomicina hacia Staphylococcus aureus mediante espectroscopia infrarroja con transformada de Fourier(Universidad Santiago de Cali, 2023) Gómez Martínez, Andrés; Vélez Bueno, Isaac Eduardo; Oñate Garzón, José Fernando; Ausili, AlessioColistin and daptomycin are clinically important antimicrobial peptides (AMPs) which are bactericidal depending on whether it is a Gram-positive or Gram-negative bacterium; both peptides are characterized by altering the permeability and organization of the cell membrane, therefore, the evaluation of the interaction between both PAMs and E. coli 25922 and S. aureus 25923 cells was carried out, analyzing membrane functional groups by Fourier Transform Infrared Spectroscopy (FTIR). In this work we report band shifts and vibrations in methyl, methylene and phosphate functional groups of the cell membrane in both strains as a consequence of interaction with colistin, unlike daptomycin which only caused representative changes in S. aureus. This establishes FTIR as a tool to explore the activity and selectivity of various PAMs in strains to combat antimicrobial resistanceItem Evaluación de la actividad antimicrobiana de péptidos obtenidos a partir de la hidrólisis enzimática de la proteína de Chenopodium quinoa frente a Staphylococcus aureus y Escherichia coli(Universidad Santiago de Cali, 2023) Penagos Montaña, Nataly; Peralta Loboa, Camilo; Oñate Garzón, José Fernando; Cardona Cardona, Yudy VanesaPeptides are amino acid polymers with bioactive properties. In this regard, quinoa (Chenopodium quinoa) is a good alternative for peptide production due to its high protein composition and abundance in the national territory. However, the high cost of synthesis has led to the search for other alternatives such as enzymatic hydrolysis, where commercial enzymes obtained from plants, like actinidin, a cysteine-protease present in kiwi (Actinidina deliciosa), with proteolytic activity on vegetable substrates, are used. In this study, enzymatic hydrolysis of quinoa protein was performed using actinidin after an alkaline extraction. The obtained peptides were quantified using the Bradford method. Finally, their antimicrobial activity against S. aureus ATCC 25923 and E. coli ATCC 25922 was evaluated. The results indicated that the obtained peptides exhibited inhibition up to 0.000509 mg/mL for S. aureus ATCC 25923 and 0.004008 mg/mL for E. coli ATCC 25922Item Evaluación de la viabilidad de probióticos encapsulados e incorporados en la formulación de un helado duro(Universidad Santiago de Cali, 2023) Plaza Jiménez, Henry; Montes Ruiz, Óscar Mauricio; Álzate, Calderón, Paola; Ramírez-Navas, Juan SebastiánThe implementation of probiotics in foods brings great health benefits. However, such probiotics are sensitive to adverse environmental conditions. For this reason, encapsulation techniques have been studied and implemented to maintain its viability. The objective of this study is to evaluate the efficiency of calcium alginate capsules with chitosan, produced by the extrusion method to maintain the viability of probiotics Lactobacillus rhamnosus CRL 1505 and Lactobacillus acidophilus LA-3 in hard ice cream and evaluate its effect on the quality parameters and sensory characteristics of the product. In terms of methodology, L. rhamnosus and L. acidophilus were incorporated as probiotic strains in the ice cream formulation. Five ice cream systems were prepared: free L. rhamnosus, encapsulated L. rhamnosus, free L. acidophilus, encapsulated L. acidophilus and a control (ice cream without probiotics). The results showed that encapsulated probiotics showed higher viability during storage compared to free probiotics and that their incorporation into the formulation didn’t affect the physicochemical parameters of the product. However, the functional parameters were negatively affected by the encapsulated probiotics. Even so, they demonstrated great acceptance in terms of their sensory properties. Concluding that hard ice cream is an optimal food product as a transport system for microencapsulated probiotics such as L. acidophilus and L. rhamnosusItem Estudio de la diversidad liquénica como bioindicador de la calidad del aire en la Universidad Santiago de Cali(Universidad Santiago de Cali, 2023) Grijalba Robles, Juan Manuel; Figueroa Tapie, Jully Viviana; Pelegrín Ramírez, Jonathan; Cerón Hernández, Víctor AlfonsoLichenized fungi are symbiotic associations between a fungus and an alga or cyanobacteria, they are resistant to adverse environmental conditions and capable of colonizing diverse ecosystems, most lichens are biomonitors and bioindicators of pollution, since they have very efficient mechanisms to absorb water and nutrients from the atmosphere, bioaccumulating pollutants without being able to eliminate them. In this study, lichen diversity was evaluated at the Universidad Santiago de Cali (USC) with the objective of determining the potential of lichens as bioindicators of air quality. A macro and microscopic characterization and identification of lichens was performed. Lichen diversity was compared with two sampling points, an urban area with signs of air pollution due to mobile sources and the industrialization of the area (Parque de la Caña) and another rural area with low pollution (Pance), both of which have direct measurements. By calculating the Atmospheric Purity Index (API), it was possible to contrast the data on lichenic biodiversity and air quality with the direct measurements of the monitoring stations and thus know the relationship between air quality and the presence or absence of certain lichenic species. The IPA obtained in the areas was 21.9 (Caña), 42.2 (USC) and 124.2 (Pance). Based on the above, with the monitoring data provided by the air quality surveillance system of Santiago de Cali (SVCASC), it was possible to find greater lichen diversity as air pollution decreased and it was particularly observed that for the USC a relatively high diversity (25 species) was reported, higher than in the urban area (P. Caña) with 7 species and lower than in the rural area (Pance) with 47 speciesItem Desarrollo de un empaque biodegradable basado en almidón de papa y aceite esencial de orégano (Origanum vulgare) para la preservación de productos cárnicos(Universidad Santiago de Cali, 2023) Ramírez Gutiérrez, Valentina; Falco Restrepo, Aura Dayana del Carmen; Álzate Calderón, PaolaThis research focuses on addressing the environmental problems caused by the excessive use of plastic, proposing the development of biodegradable packaging to preserve meat and offer an alternative to petroleum- derived plastic packaging. Regarding the experimental part, biodegradables films were elaborated using potato starch, chitosan, and the effect of the addition of different concentrations of oregano essential oil (0%, 0.25%, 0.50%, and 1%) used as antimicrobial, in the formulation of the elaborated films was evaluated. The results showed that, in the physicochemical tests (solubility, humidity, and thickness), the films tended to increase these properties as the AEO content increased. Regarding the microbiological results, it was observed that the microbial inhibition halos are greater as the concentration of oregano essential oil increases and that the oil acts better against Gram- positive bacteria than against Gram-negative bacteria. As a general conclusion, it can be indicated that the films elaborated prove to be a viable alternative to conventional packaging, showing a promising future in this area of research