Productos de investigación

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12585/8849

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Assessing Forest Cover Loss Using Landsat Images and GIS: A Case Study in Colombian Protected Area
(2022) Miranda-Castro, Wendy; Acevedo-Barrios, Rosa; Guerrero, Milton; Guzmán, Katherine; de Gorostizaga, Sayana
The Corchal “El Mono Hernández” Fauna and Flora Sanctuary is a protected area located in northern Colombia and is home to the Pterocarpus officinalis forest. In this area, however, this forest cover is declining due to natural causes associated with a change in the hydrosedimentological dynamics. Multitemporal assessment was performed to quantify the forest loss. Landsat images from the years 1986, 1998, 2003, 2013, and 2018 were downloaded and a supervised classification was performed using four cover classes: “Pterocarpus officinalis,” “other vegetation,” “waterbody,” and “bare land.” The results showed that the vegetation cover of Pterocarpus officinalis forest had an initial extent of 865.26 ha in 1986; for the 1986–1998 period, the reduction was 60.30 ha; for the 1998–2003 period, it was 399.15 ha; and for the 2003–2013 period, it was 78.30 ha. Contrary to previous periods, in the 2013–2018 period, 79.65 ha of forest was recovered. In conclusion, Pterocarpus officinalis forest lost approximately 50% of its cover during the 1986–2018 period. This information is of great importance for government and management entities for decision-making in the conservation and restoration of this forest. © 2022 Taylor & Francis.
Bioprospecting of extremophilic perchlorate‑reducing bacteria: report of promising Bacillus spp. isolated from sediments of the bay of Cartagena, Colombia
(2023-12-12) Acevedo-Barrios, Rosa; Tirado‑Ballestas, Irina; Bertel‑Sevilla, Angela; Cervantes‑Ceballos, Leonor; Gallego, Jorge L.; Leal, María Angélica; Tovar, David; Olivero‑Verbel, Jesús
Three extremophile bacterial strains (BBCOL-009, BBCOL-014 and BBCOL-015), capable of degrading high concentrations of perchlorate at a range of pH (6.5 to 10.0), were isolated from Colombian Caribbean Coast sediments. Morphological features included Gram negative strain bacilli with sizes averaged of 1.75 × 0.95, 2.32 × 0.65 and3.08 × 0.70 μm, respectively. The reported strains tolerate a wide range of pH (6.5 to 10.0); concentrations of NaCl (3.5 to 7.5% w/v) and KClO4− (250 to 10000 mg/L), reduction of KClO4 − from 10 to 25%. LB broth with NaCl (3.5–30% w/v) and KClO4ˉ(250-10000 mg/L) were used in independent trialsto evaluate susceptibility to salinity and perchlorate,respectively. Isolates increased their biomass at 7.5 % (w/v) NaCl with optimal development at 3.5 % NaCl. Subsequently, ClO reduction was assessed using LB medium with 3.5% NaCl and 10000 mg/L ClO4 BBCOL-009, BBCOL-014 and BBCOL-015 achieved 10%, 17%, and 25% reduction of ClO4 respectively. The 16 S rRNA gene sequence grouped them as Bacillus flexus T6186-2, Bacillus marisflavi TF-11 (T), and Bacillus vietnamensis 15 − 1 (T) respectively, with < 97.5% homology. In addition, antimicrobial resistance to ertapenem, vancomycine, amoxicillin clavulanate, penicillin, and erythromycin was present in all the isolates, indicating their high adaptability to stressful environments. The isolated strains from marine sediments in Cartagena Bay, Colombia are suitable candidates to reduce perchlorate contamination in different environments. Although the primary focus of the study of perchlorate-reducing and resistant bacteria is in the ecological and agricultural realms, from an astrobiological perspective, perchlorate-resistant bacteria serve as models for astrobiological investigations.
Concentrations of Airborne Cultivable Fungi at a Higher Education Institution in Cartagena de Indias, Colombian Caribbean
(2022) Rubiano-Labrador, Carolina; Baena De Avila, Ludys; Doria Posada, Dayana; Acevedo-Barrios, Rosa
Bioaerosols are as small particles suspended in air that contain several microorganisms (bacteria, fungi, and viruses). These particles are studied because of the possible impacts that they have on the health of humans and animals in open and closed spaces. In this study, the presence of airborne fungi presents in a Higher Education Institution (HEI) of the city of Cartagena de Indias, Colombian Caribbean was evaluated. Over 4 months (June–October 2018), 128 fungal samples were collected using a two-stage cascade impactor, and the fungi present in these samples were counted, characterized, and identified. Bioaerosol concentrations were correlated with meteorological data from the Rafael Núñez Airport meteorological station to establish the possible influence of these factors on the presence of bioaerosols. The results obtained showed an average concentration of fungal aerosols of 123.71 ± 17.97 UFC/m3, with the highest proportion occurring in the morning. The predominant genera were Aspergillus (60.8%), followed by Penicillium (24.5%) and Fusarium (9.3%). According to the correlations obtained from a multivariate analysis, the meteorological parameters did not influence the presence of microorganisms at the HEI studied; however, a possible influence of emission sources such as vegetation and industry is suggested. © 2022, The Author(s) under exclusive licence to Institute of Earth Environment, Chinese Academy Sciences.
Determining Changes in Mangrove Cover Using Remote Sensing with Landsat Images: a Review
(2023-12-22) Vasquez, Juan; Acevedo-Barrios, Rosa; Miranda‑Castro, Wendy; Guerrero, Milton; Meneses‑Ospina, Luisa
Mangroves are ecosystems within the intertidal zone of tropical and subtropical coasts; they offer ecosystem services such as protection from coastal erosion and storms and flood control, act as carbon sinks and are also sources of income by providing various forest products. However, their cover is rapidly disappearing worldwide, which makes the diagnosis and monitoring of the state of these important ecosystems, as well as their restoration and conservation, a challenge. Remote sensing is a promising technique that provides accurate and efficient results in the mapping and monitoring of these ecosystems. The Landsat sensor provides the most used medium-resolution images for this type of study. The main objective of this article is to provide an updated review of the main remote sensing techniques, specifically Landsat satellite imagery, used in the detection of changes and mapping of mangrove forests, as well as a review of climatic and/or chemical factors related to changes in the spatial distribution of these ecosystems.
Identification by MALDI-TOF MS of bacterial microorganisms associated with dental caries
(2023-12-09) Jimenez-Ramirez, Verónica Alejandra; Acevedo-Barrios, Rosa; Parra-Giraldo, Claudia Marcela; Sánchez-Quitian, Zilpa Adriana; Ariza-Rua, Danilo Lusbin; Chavarro-Mesa, Edisson; Martinez-Santos, Juan Carlos
It is essential to understand bacterial succession during the development of dental caries and determine the microorganisms related to this disease. This work aimed to identify bacteria associated with cariogenic pieces and carry out an antibiogram assay. First, we isolated bacterial isolates using MALDI TOF-MS and species-specific PCR techniques. Next, we implemented an antibiogram test to evaluate antimicrobial susceptibility events in Streptococcus oralis, Staphylococcus epidermidis, and Bacillus cereus. Our results showed that the bacterial species frequently associated with cariogenic processes was S. oralis. The antibiogram analysis determined that the most effective antibiotic was streptomycin, with a minimal significant difference of 0.52. Furthermore, the phylogenetic reconstruction allowed confirming the identity of the Colombian isolates that were sequenced, corresponding to the species S. oralis. Finally, we describe the complex etiology of dental caries where not only one bacterial agent is related to the development of this pathology. It is a complex of species.
Monitoring Conservation of Forest in Protected Areas using Remote Sensing Change Detection Approach: a Review
(2022) Miranda-Castro, Wendy; Acevedo-Barrios, Rosa; Guerrero, Milton
Abstract: Deforestation and fragmentation threaten biodiversity owing to their impacts on many species. To prevent and minimise the problem, protected areas have been created with the aim of conserving biodiversity, and parts of continental territories have been designated for this purpose. However, these areas are not exempt from forest loss and can be directly and indirectly disturbed by surrounding territories, natural disasters, climate, and human actions. In addition, the management quality of many protected areas is unknown. Thus, forest change detection using remote sensing data has been implemented as an approach to assess forest loss in conservation areas, since it generates spatio-temporal information about the protected forest area, which can then be used to improve forest management and decision making. This article reviews the approaches that have been implemented to study forest changes in protected areas. © 2022, Pleiades Publishing, Ltd.
Perchlorate in antarctica, origin, effects, treatments, environmental fate, and astrobiological perspectives: a review
(2022-08-19) Acevedo-Barrios, Rosa; Puentes Martínez, Dainis; Hernández Rocha, Isis; Rubiano‑Labrador, Carolina; De la Parra‑Guerra, Ana; Carranza‑López, Liliana; Monroy‑Licht, Andrea; Leal, María Angelica; López, David
Perchlorate (ClO4−), which is a powerful endocrine disruptor affecting iodine fixation in the thyroid gland in humans and in biota, is a pollutant of natural and anthropogenic origin. For this reason, this pollutant must be eliminated from the ecosystems.It has been found in extreme environments such as Antarctica. ClO−reduction can be achieved with physicochemicaltreatments in small concentrations and through bacterial degradation. This is a cost-effective method, easy to implement,which makes it a viable method for the removal of perchlorate contamination in ecosystems. This review provides an updateddiscussion of reducing perchlorate contamination; that includes different perspectives of investigations related to its origin,use, effects on living beings; as well as the technologies used to eliminate this pollutant from the environment; its environmental fate in strategic ecosystems such as Antarctica in particular and astrobiological perspectives.
Presence of perchlorate in marine sediments from Antarctica during 2017–2020
(2022-01-17) Acevedo-Barrios, Rosa; Rubiano-Labrador, Carolina; Miranda-Castro, Wendy
Perchlorate of natural origin is a persistent pollutant that affects thyroid function by inhibiting iodine uptake, and this pollutant is frequently detected in different ecosystems at concentrations that can harm human health. In this study, we measured the perchlorate concentrations in 3,000 marine sediment samples from January to March in 2017, 2018, 2019, and 2020 during the 3rd, 4th, 5th, and 6th Colombian Scientific Expeditions to Antarctica. The sampling zones were located at 15 different points on the South Shetland Islands and Antarctic Peninsula, and they were measured using a selective perchlorate electrode. The concentration data indicate that perchlorate reached a minimum concentration of 90 ppm on Horseshoe Island and a maximum concentration of 465 ppm on Deception Island, suggesting a spatial variation in perchlorate concentrations that can be attributed to the natural formation of this pollutant due to volcanic eruptions. Additionally, homogeneous distribution of perchlorate was not observed in Antarctica
Pseudomonas strains from the Livingston Island, Antarctica: a source of cold-active hydrolytic enzymes
(2022-07) Rubiano-Labrador, Carolina; Acevedo-Barrios, Rosa; García Lazaro, Alba; Ward Bowie, Lilia; Támara Acosta, Ana Karina; Mercado Molina, Blanca
Pseudomonas spp. is considered one of the most successful bacterial genera due to its plasticity and metabolic versatility, which has allowed it to colonize different ecosystems, including Antarctica. The ability of Pseudomonas to adapt an d survive in the hostile conditions of the Antarctic makes them a reservoir of enzymes that can be used in different biotechnological applications; however, research on this genus in Antarctica is still in its infancy. Therefore, the aim of this study was to isolate and characterise cold-adapted Pseudomonas from Livingston Island, Antarctica, and expl ore th eir abi l ity to produce cold-active hydrolytic enzymes. In the present study, we isolated seven cold-adapted bacteria related to the genus Pseudomonas. The isolated strains have the ability to produce hydrolytic enzymes. These results demonstrate that cold-adapted Pseudomonas from Antarctica are a promising source of cold-active enzymes with biotechnological potential.

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