Pub Date : 2022-12-16DOI: 10.11144/javeriana.sc273.eonc
Diego Rúgeles, Brayan Gámez-Castillo, Vanessa Gómez, Patricia Hernández Rodríguez
Pseudomonas aeruginosa is a Gram-negative bacterium designated by the WHO as a critical priority microorganism due to its virulence, controlled by a quorum sensing (QS) system. QS is regulated} through specific subsystems: LasI/LasR, RhlI/RhlR, and PQS/MvfR. Several natural compounds can inhibit these QS mechanisms. In this study, we determined the effect of curcumin, reserpine, and their mixtures with two commercial antibiotics (gentamicin and azithromycin) on P. aeruginosa QS mechanisms: mvfR gene expression and the production of pyocyanin and rhamnolipids. Antibiotic and natural compounds’ minimal inhibitory concentrations (MICs) were determined via microdilution assays. Gentamicin, azithromycin, curcumin, reserpine, and their mixtures exerted variable effects on mvfR gene expression, as assessed via semi-quantitative RT-PCR assays. Curcumin, reserpine, and gentamicin inhibited mvfR gene expression better than azithromycin, and the mixtures curcumin-gentamicin and reserpine-gentamicin outperformed gentamicin alone in inhibiting mvfR gene expression and decreasing pyocyanin and rhamnolipids production, revealing the synergistic effect of these mixture components. The mixtures of curcumin and gentamicin and reserpine and gentamicin may become alternatives to complement or enhance conventional methods currently used to treat P. aeruginosa infections.
{"title":"Effects of natural compounds and commercial antibiotics on Pseudomonas aeruginosa quorum sensing","authors":"Diego Rúgeles, Brayan Gámez-Castillo, Vanessa Gómez, Patricia Hernández Rodríguez","doi":"10.11144/javeriana.sc273.eonc","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.eonc","url":null,"abstract":"Pseudomonas aeruginosa is a Gram-negative bacterium designated by the WHO as a critical priority microorganism due to its virulence, controlled by a quorum sensing (QS) system. QS is regulated} through specific subsystems: LasI/LasR, RhlI/RhlR, and PQS/MvfR. Several natural compounds can inhibit these QS mechanisms. In this study, we determined the effect of curcumin, reserpine, and their mixtures with two commercial antibiotics (gentamicin and azithromycin) on P. aeruginosa QS mechanisms: mvfR gene expression and the production of pyocyanin and rhamnolipids. Antibiotic and natural compounds’ minimal inhibitory concentrations (MICs) were determined via microdilution assays. Gentamicin, azithromycin, curcumin, reserpine, and their mixtures exerted variable effects on mvfR gene expression, as assessed via semi-quantitative RT-PCR assays. Curcumin, reserpine, and gentamicin inhibited mvfR gene expression better than azithromycin, and the mixtures curcumin-gentamicin and reserpine-gentamicin outperformed gentamicin alone in inhibiting mvfR gene expression and decreasing pyocyanin and rhamnolipids production, revealing the synergistic effect of these mixture components. The mixtures of curcumin and gentamicin and reserpine and gentamicin may become alternatives to complement or enhance conventional methods currently used to treat P. aeruginosa infections.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41564192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-12DOI: 10.11144/javeriana.sc273.eeof
R. Hegazy, G. Mohammad, Magdy Ibrahim Mohamed
Calibration laboratories often face the challenge of the impossibility to perform full capacity range calibration of their force transducers, particularly below 10 % of the force transducer’s capacity. Sometimes these laboratories use curve fitting extrapolation to estimate and predict force transducer behavior within uncalibrated capacity ranges. This work deals with the study of extrapolation errors in force transducers to know and estimate prediction accuracies when using extrapolation for force transducer calibration in ranges below 10 % and between 50 % and 100 % of the transducer’s capacity. The results of this study showed that the magnitude of the extrapolation error is very close to the magnitude of the reproducibility error within calibrated capacity ranges in the laboratory.
{"title":"Extrapolation errors of force transducer curve fitting equations","authors":"R. Hegazy, G. Mohammad, Magdy Ibrahim Mohamed","doi":"10.11144/javeriana.sc273.eeof","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.eeof","url":null,"abstract":"Calibration laboratories often face the challenge of the impossibility to perform full capacity range calibration of their force transducers, particularly below 10 % of the force transducer’s capacity. Sometimes these laboratories use curve fitting extrapolation to estimate and predict force transducer behavior within uncalibrated capacity ranges. This work deals with the study of extrapolation errors in force transducers to know and estimate prediction accuracies when using extrapolation for force transducer calibration in ranges below 10 % and between 50 % and 100 % of the transducer’s capacity. The results of this study showed that the magnitude of the extrapolation error is very close to the magnitude of the reproducibility error within calibrated capacity ranges in the laboratory.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45619961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-04DOI: 10.11144/javeriana.sc273.mait
Miguel Valderrama-Herrera, K. Kanagusuku, Sergio Ramírez-Amaro
Records about morphological abnormalities in rays of the genus Myliobatis are scarce worldwide. In the present study, three specimens exhibiting different malformations were identified during the monitoring of the reproductive biology of the Chilean eagle ray Myliobatis chilensis, conducted from 2017 to 2018 in the fishing port of Salaverry (northern Peru). The identified specimens included: (i) a female with split pectoral fins, (ii) a male with an unfused-to-the-head pectoral fin, and (iii) a female with a short and thick tail. Here we report and discuss the implications and likely causes of these first three cases of morphological abnormalities in M. chilensis from the western Pacific.
{"title":"Morphological abnormalities in the Chilean Eagle ray Myliobatis chilensis (Myliobatiformes: Myliobatidae) off the Peruvian coast, Southeast Pacific","authors":"Miguel Valderrama-Herrera, K. Kanagusuku, Sergio Ramírez-Amaro","doi":"10.11144/javeriana.sc273.mait","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.mait","url":null,"abstract":"Records about morphological abnormalities in rays of the genus Myliobatis are scarce worldwide. In the present study, three specimens exhibiting different malformations were identified during the monitoring of the reproductive biology of the Chilean eagle ray Myliobatis chilensis, conducted from 2017 to 2018 in the fishing port of Salaverry (northern Peru). The identified specimens included: (i) a female with split pectoral fins, (ii) a male with an unfused-to-the-head pectoral fin, and (iii) a female with a short and thick tail. Here we report and discuss the implications and likely causes of these first three cases of morphological abnormalities in M. chilensis from the western Pacific.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42087389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-02DOI: 10.11144/javeriana.sc273.oaou
Carlos A Guerrero-Fonseca, Pedro Moreno-Beltrán, Angie Bedoya-Rodriguez, Bibiana Pazos-Valencia, Juan Sebastián Bedoya-Trujillo, Orlando Acosta
Several in vitro models have investigated the consequences of mechanical stimuli on osteoclasts (OCs). However, the mechanisms whereby mechanical forces trigger osteoclast responses remain poorly understood, and the generation of reactive oxygen species (ROS) and their relationship with bone resorption in OCs under the influence of mechanical forces require investigation. The present work examined the role of centrifugal force application on ROS production and its effect on osteoclast activity and differentiation. Human U937 macrophage cells, peripheral blood mononuclear cells (PBMCs), and periodontal ligament (PDL) fibroblasts treated with polyethylene glycol (PEG) or N-acetylcysteine (NAC) were subject to centrifugal force. Osteoclast markers such as tartrate-resistant acid phosphatase (TRAP) and bone resorption activities were measured. ROS levels and actin ring formation were determined. Also, U937 cell responses to centrifugal force and PEG-induced fusion were studied. Individual cells subjected to centrifugal exertion increased their ROS levels, formed actin-like rings, revealed TRAP expression and bone resorption activities, and expressed typical osteoclast markers. Control PEG-fused U937 cells also showed these effects, and cell treatment with NAC stopped all these responses. Centrifugal force, as well as PEG-induced cell fusion, can promote osteoclast-like features, including oxidative stress. The present experimental model allowed us to understand the mechanisms underlying the osteoclast differentiation associated with ROS production stimulated by mechanical compressive force, where NAC can contribute to reducing this oxidative stress condition.
{"title":"Osteoclast-like activity of U937 cells, peripheral blood mononuclear cells, and periodontal ligament fibroblasts subjected to mechanical stress by centrifugal force","authors":"Carlos A Guerrero-Fonseca, Pedro Moreno-Beltrán, Angie Bedoya-Rodriguez, Bibiana Pazos-Valencia, Juan Sebastián Bedoya-Trujillo, Orlando Acosta","doi":"10.11144/javeriana.sc273.oaou","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.oaou","url":null,"abstract":"Several in vitro models have investigated the consequences of mechanical stimuli on osteoclasts (OCs). However, the mechanisms whereby mechanical forces trigger osteoclast responses remain poorly understood, and the generation of reactive oxygen species (ROS) and their relationship with bone resorption in OCs under the influence of mechanical forces require investigation. The present work examined the role of centrifugal force application on ROS production and its effect on osteoclast activity and differentiation. Human U937 macrophage cells, peripheral blood mononuclear cells (PBMCs), and periodontal ligament (PDL) fibroblasts treated with polyethylene glycol (PEG) or N-acetylcysteine (NAC) were subject to centrifugal force. Osteoclast markers such as tartrate-resistant acid phosphatase (TRAP) and bone resorption activities were measured. ROS levels and actin ring formation were determined. Also, U937 cell responses to centrifugal force and PEG-induced fusion were studied. Individual cells subjected to centrifugal exertion increased their ROS levels, formed actin-like rings, revealed TRAP expression and bone resorption activities, and expressed typical osteoclast markers. Control PEG-fused U937 cells also showed these effects, and cell treatment with NAC stopped all these responses. Centrifugal force, as well as PEG-induced cell fusion, can promote osteoclast-like features, including oxidative stress. The present experimental model allowed us to understand the mechanisms underlying the osteoclast differentiation associated with ROS production stimulated by mechanical compressive force, where NAC can contribute to reducing this oxidative stress condition.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48009291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-15DOI: 10.11144/javeriana.sc273.pacof
Luz Marina Baena, G. Guerrero-Álvarez, Maria Camila Giraldo-González
Silk fibroin (SF) is a biomacromolecule composed of proteins with properties, such as biocompatibility, biodegradability, and low immunogenicity. Thus, Silk fibroin nanoparticles (FNps) overcome the disadvantages of non-degradable synthetic nanoparticles. We studied the structural and thermal properties of SF and FNps from Bombyx mori L. cross-breed Pilamo I cocoons. Raw fibroin (RF) was obtained using a sodium Na2CO3 solution as part of an experimental design to improve extraction, and FNps were obtained by denaturing RF with a ternary solution of CaCl2:H2O:CH3CH2OH, followed by precipitation using an anti-solvent method with propanol. Pilamo I cocoon, RF, and FNps were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy(SEM), and elemental chemical analysis of energy dispersive X-rays (EDS). The Light Scattering (DLS) and the thermal properties of RF and FNps were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The FTIR results showed that sericin-free raw fibroin was obtained, and the SEM results showed that the nanometer-sized particles had a globular structure and apparent porosity. The differences in the enthalpy of the crystallization peaks in the DSC and TGA curves showed that the FNps had higher thermal stability than RF fibers. This result furthers the development of alternative materials as vehicles of active compounds from natural extracts.
{"title":"Preparation and characterization of fibroin nanoparticles obtained from Bombyx mori L. Pilamo 1 cocoons","authors":"Luz Marina Baena, G. Guerrero-Álvarez, Maria Camila Giraldo-González","doi":"10.11144/javeriana.sc273.pacof","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.pacof","url":null,"abstract":"Silk fibroin (SF) is a biomacromolecule composed of proteins with properties, such as biocompatibility, biodegradability, and low immunogenicity. Thus, Silk fibroin nanoparticles (FNps) overcome the disadvantages of non-degradable synthetic nanoparticles. We studied the structural and thermal properties of SF and FNps from Bombyx mori L. cross-breed Pilamo I cocoons. Raw fibroin (RF) was obtained using a sodium Na2CO3 solution as part of an experimental design to improve extraction, and FNps were obtained by denaturing RF with a ternary solution of CaCl2:H2O:CH3CH2OH, followed by precipitation using an anti-solvent method with propanol. Pilamo I cocoon, RF, and FNps were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy(SEM), and elemental chemical analysis of energy dispersive X-rays (EDS). The Light Scattering (DLS) and the thermal properties of RF and FNps were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The FTIR results showed that sericin-free raw fibroin was obtained, and the SEM results showed that the nanometer-sized particles had a globular structure and apparent porosity. The differences in the enthalpy of the crystallization peaks in the DSC and TGA curves showed that the FNps had higher thermal stability than RF fibers. This result furthers the development of alternative materials as vehicles of active compounds from natural extracts.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46188258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-06DOI: 10.11144/javeriana.sc272.coss
Brayan Stiven Arango, Sebastián Peña Buitrago, Jhon Carlos Castaño Osorio, C. V. Granobles Velandia
Shiga toxin producing Escherichia coli (STEC) is a bacterial pathogen that causes diarrhea and severe human diseases like HUS; its main virulence factor are the Shiga toxins (Stx1 and Stx2). Some Stx2 subtypes have been identified and associated with the risk of developing severe illness. Stx toxins are encoded in temperate bacteriophages which control their expression through the lytic cycle that is regulated by the late genes and Q anti-terminator protein. The aim of this work was to characterize six STEC strains carrying Stx2-phages to provide preliminary information and understanding about Stx2 strains from Colombia regarding the Stx production, lytic cycle induction and subtyping of Stx2. Two highlighted strains with higher levels of Stx production and lytic cycle’s induction were observed. All the evaluated strains carried either the Stx2a, Stx2c, or Stx2d subtypes. In addition, most of the strains carried the qO111 allele, and only one strain showed differences in the ninG region. Differences in the evaluated characteristics of the strains were observed, which could indicate the variability of these six STEC strains carrying Stx2-phages.
{"title":"Characterization of six Shiga toxin-producing Escherichia coli (STEC) strains carrying Stx2-phages from Colombia","authors":"Brayan Stiven Arango, Sebastián Peña Buitrago, Jhon Carlos Castaño Osorio, C. V. Granobles Velandia","doi":"10.11144/javeriana.sc272.coss","DOIUrl":"https://doi.org/10.11144/javeriana.sc272.coss","url":null,"abstract":"Shiga toxin producing Escherichia coli (STEC) is a bacterial pathogen that causes diarrhea and severe human diseases like HUS; its main virulence factor are the Shiga toxins (Stx1 and Stx2). Some Stx2 subtypes have been identified and associated with the risk of developing severe illness. Stx toxins are encoded in temperate bacteriophages which control their expression through the lytic cycle that is regulated by the late genes and Q anti-terminator protein. The aim of this work was to characterize six STEC strains carrying Stx2-phages to provide preliminary information and understanding about Stx2 strains from Colombia regarding the Stx production, lytic cycle induction and subtyping of Stx2. Two highlighted strains with higher levels of Stx production and lytic cycle’s induction were observed. All the evaluated strains carried either the Stx2a, Stx2c, or Stx2d subtypes. In addition, most of the strains carried the qO111 allele, and only one strain showed differences in the ninG region. Differences in the evaluated characteristics of the strains were observed, which could indicate the variability of these six STEC strains carrying Stx2-phages.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44074121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-06DOI: 10.11144/javeriana.sc273.fsof
Daniel Restrepo Santamaria, A. Navia, J. Palacio, L. Jiménez-Segura
Construction of dams for hydropower in Andean rivers of Colombia is increasing loss of species of the region. Fish species that persist in these artificial ecosystems are those which find favorable the new conditions for their recruitment. Because feeding is one of the fish life strategies that influence their persistence in reservoirs, we analyzed the stomach contents of the species present in two cascade reservoirs in the Magdalena river basin. The objectives were to describe the diet, to determine their feeding strategies and to evaluate if the rainy season or spatial distribution affects the diet of the fish species. Our results indicate that the fish species Brycon henni and Astyanax microlepis that feed on a wide range of resources that the system offers and adopt a generalist strategy. Also, opportunistic species such as Roeboides dayi and Hoplosternum magdalenae occupied these environments. Climatic seasonality does not influence the feeding habits of the fish species inhabiting the study reservoirs. Knowledge of the feeding habits of fish species is a priority for strengthening the environmental management of aquatic resources of the Andes.
{"title":"Feeding strategy of fish that colonize reservoirs in the Magdalena river basin","authors":"Daniel Restrepo Santamaria, A. Navia, J. Palacio, L. Jiménez-Segura","doi":"10.11144/javeriana.sc273.fsof","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.fsof","url":null,"abstract":"Construction of dams for hydropower in Andean rivers of Colombia is increasing loss of species of the region. Fish species that persist in these artificial ecosystems are those which find favorable the new conditions for their recruitment. Because feeding is one of the fish life strategies that influence their persistence in reservoirs, we analyzed the stomach contents of the species present in two cascade reservoirs in the Magdalena river basin. The objectives were to describe the diet, to determine their feeding strategies and to evaluate if the rainy season or spatial distribution affects the diet of the fish species. Our results indicate that the fish species Brycon henni and Astyanax microlepis that feed on a wide range of resources that the system offers and adopt a generalist strategy. Also, opportunistic species such as Roeboides dayi and Hoplosternum magdalenae occupied these environments. Climatic seasonality does not influence the feeding habits of the fish species inhabiting the study reservoirs. Knowledge of the feeding habits of fish species is a priority for strengthening the environmental management of aquatic resources of the Andes.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43667550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.11144/javeriana.sc273.seam
Liliana Marcela Rincón Fuentes, Lucia Marlen Moreno Bastidas, Oscar Julio Medina Vargas
This paper’s aim was the synthesis of a flocculant useful in the production of panela as an alternative to replace polyacrylamide and improve food safety in Boyacá, a Colombian district. The cellulose was extracted by using a treatment with potassium hydroxide and followed by acid hydrolysis. From the extracted cellulose, cationic dialdehyde cellulose (CDAC) was synthesized and both cellulose and CDAC were characterized using infrared spectroscopy, FTIR, thermogravimetric analysis (TGA), differential thermal analysis (DSC) Scanning Electron Microscopy (SEM) and RAMAN. The cellulose extracted by hydrolysis from sugarcane bagasse with bleaching, gave yield of 50 % and crystallinity index of 77 %. Its modification to aldehyde is 95 % reliable at a temperature of 65 osoC and 2 h; with higher temperature and time the performance is affected. The dialdehyde process allows a modification to be carried out and to be more easily attacked at carbons 2 and 3, leaving cationized cellulose for later use as a flocculant in the panela production process as a traditional solution of flocculants and polyacrylamide. Extraction, modification, and tests for the clarification of the panela juice were carried out in triplicate.
{"title":"Selective extraction and modification of cellulose from sugar cane bagasse (Saccharum officinarum)","authors":"Liliana Marcela Rincón Fuentes, Lucia Marlen Moreno Bastidas, Oscar Julio Medina Vargas","doi":"10.11144/javeriana.sc273.seam","DOIUrl":"https://doi.org/10.11144/javeriana.sc273.seam","url":null,"abstract":"This paper’s aim was the synthesis of a flocculant useful in the production of panela as an alternative to replace polyacrylamide and improve food safety in Boyacá, a Colombian district. The cellulose was extracted by using a treatment with potassium hydroxide and followed by acid hydrolysis. From the extracted cellulose, cationic dialdehyde cellulose (CDAC) was synthesized and both cellulose and CDAC were characterized using infrared spectroscopy, FTIR, thermogravimetric analysis (TGA), differential thermal analysis (DSC) Scanning Electron Microscopy (SEM) and RAMAN. The cellulose extracted by hydrolysis from sugarcane bagasse with bleaching, gave yield of 50 % and crystallinity index of 77 %. Its modification to aldehyde is 95 % reliable at a temperature of 65 osoC and 2 h; with higher temperature and time the performance is affected. The dialdehyde process allows a modification to be carried out and to be more easily attacked at carbons 2 and 3, leaving cationized cellulose for later use as a flocculant in the panela production process as a traditional solution of flocculants and polyacrylamide. Extraction, modification, and tests for the clarification of the panela juice were carried out in triplicate.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45674419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Urban wetlands are biodiversity reservoirs sustained by microbe-mediated processes. In tropical zones, wetland microbial dynamics remain poorly understood. Chemical parameters, heavy metal content, and microbiological community structure were investigated in surface sediments of the Santa Maria del Lago (SML) wetland in Bogota, Colombia. High-throughput sequencing was employed to generate RNAr 16S and nosZ gene sequence data with which bacteria, archaea, and nosZ-type denitrifier community composition and their phylogenetic relationships were investigated. A canonical correspondence analysis was conducted to determine the relationship between assessed environmental variables and microbial community composition. Results showed that the most abundant bacterial phyla were Proteobacteria, Acidobacteria (group GP18), and Aminicenantes; Archaea were represented by the taxa Methanomicrobia and Thermoprotei, and the nosZ community was dominated by Candidatus Competibacter denitrificans. A phylogenetic analysis revealed a high diversity of Operational Taxonomic Units (OTUs), according to 16S rRNA gene sequence data; however, the quantity and diversity of OTUs from the nosZ community were low compared to previous studies. High concentrations of ammonium, phosphorus, organic carbon, Pb, Fe, Zn, Cu, and Cd, were detected in sediments, but they were not strongly related to observed microbial community compositions. In conclusion, in the same polluted SML wetland sediments diverse bacteria and archaea communities were detected, although not nosZ-type denitrifiers.
{"title":"Bacterial communities in sediments of an urban wetland in Bogota, Colombia","authors":"Maribeb Castro González, Mauricio Edilberto Pacheco Montealegre, Mariana Restrepo Benavides","doi":"10.11144/javeriana.sc272.bcis","DOIUrl":"https://doi.org/10.11144/javeriana.sc272.bcis","url":null,"abstract":"Urban wetlands are biodiversity reservoirs sustained by microbe-mediated processes. In tropical zones, wetland microbial dynamics remain poorly understood. Chemical parameters, heavy metal content, and microbiological community structure were investigated in surface sediments of the Santa Maria del Lago (SML) wetland in Bogota, Colombia. High-throughput sequencing was employed to generate RNAr 16S and nosZ gene sequence data with which bacteria, archaea, and nosZ-type denitrifier community composition and their phylogenetic relationships were investigated. A canonical correspondence analysis was conducted to determine the relationship between assessed environmental variables and microbial community composition. Results showed that the most abundant bacterial phyla were Proteobacteria, Acidobacteria (group GP18), and Aminicenantes; Archaea were represented by the taxa Methanomicrobia and Thermoprotei, and the nosZ community was dominated by Candidatus Competibacter denitrificans. A phylogenetic analysis revealed a high diversity of Operational Taxonomic Units (OTUs), according to 16S rRNA gene sequence data; however, the quantity and diversity of OTUs from the nosZ community were low compared to previous studies. High concentrations of ammonium, phosphorus, organic carbon, Pb, Fe, Zn, Cu, and Cd, were detected in sediments, but they were not strongly related to observed microbial community compositions. In conclusion, in the same polluted SML wetland sediments diverse bacteria and archaea communities were detected, although not nosZ-type denitrifiers.","PeriodicalId":39200,"journal":{"name":"Universitas Scientiarum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45922904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-30DOI: 10.11144/javeriana.sc272.csit
C. A. Ramírez-Bernate, H. Martinez-Romero, Diana Marcela Erazo-Borja
In this work, we analyze the population dynamics of the Aedes aegypti mosquito, a transmitter of various viruses such as dengue, zika, and chikungunya, in a given area, based on the use of various control techniques. To do this, we use a reaction-diffusion model that considers various environmental characteristics such as temperature and landscape shape. Initially, we do this analysis using larvicides, insecticides, and the SIT (sterile insect release) technique separately. We simulate different control scenarios using appropriate numerical methods, test combinations of these techniques, and determine the efficiency of each strategy according to the overall reduction in the number of fertilized females due to the applied technique. Subsequently, through a cost-effectiveness analysis, we verified that the release of sterile mosquitoes at the beginning of each seasonal period is the best strategy to control the population of Aedes aegypti.
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