Browsing by Author "Cevallos Cevallos, Juan Manuel"

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Characterization of the microbial community associated with the roots of joyapa (Macleania rupestris) and the effect of fungal isolates on seedling developmentt
(2023) Cevallos Cevallos, Juan Manuel; Curillo Santos, Diana Lorena; Peña Tapia, Denisse Fabiola; Chica Martínez, Eduardo José
Macleania rupestris is a native Ericaceae with high potential benefits for health and the environment. Characterizing the interactions between M. rupestris and associated fungi is vital to supporting the plant's conservation and future domestication. However, little is known about the relationship between plant growth-promoting endophytes and M. rupestris. To learn more about the soil-associated microbiota of M. rupestris, we analyzed endophyte communities associated with the plant's rhizosphere and surrounding soil using nanopore sequencing. Additionally, fungal endophyte cultivable strains were isolated from the roots of M. rupestris to evaluate their growth-promoting activity on seedlings by applying a strain inoculation bioassay. Over 1000 genera were identified using nanopore sequencing, Bradyrhizobium and Mesorhizobium the most abundant in all samples analyzed. Similarly, six cultivable fungi were characterized by the molecular markers ITS (internal transcribed spacer) and LSU (large subunit). Amongst all isolates, Clonostachys rosea and Trichoderma paravidescens positively impacted seedlings' development. This study shows the potential of fungal strains as inoculants for the potential domestication of Macleania rupestris.
Effect of different drying airflows and harvest periods on the quality of specialty coffee (Coffea arabica L.)
(2023) Ortiz Ulloa, Silvia Johana
Coffee is one of the most consumed commercial beverages worldwide, and coffee growers are constantly seeking innovative processing techniques to improve the quality of the final product. This study evaluated the influence of four drying airflows and three harvest periods on the chemical composition of green and roasted specialty coffee beans. The samples were obtained from the Hacienda La Papaya in Loja, Ecuador. Liquid and gas chromatographic techniques characterized the chemical profile of coffee beans, and sensory analysis was performed using the Specialty Coffee Association of America methodology. In total, 49 compounds were described, 29 in green beans and 20 in roasted beans. A significant (p<0.05) effect of the harvest period was observed in all phenolic compounds except for chlorogenic acid. The drying type significantly affected the levels of rutin and trigonelline. In addition, samples from different harvest periods observed significant differences in the levels of the amino acids serine, arginine, phenylalanine and leucine. Similarly, the drying type significantly influenced glycine, alanine, valine and isoleucine levels. For all drying-harvest combinations, the final cupping score was higher than 85/100, as the different drying processes slightly influenced the cupping attributes. Drying with minimal airflow was characterized by a low balance and intense flavor while drying with medium airflow presented a high ratio and soft body. The harvest period and drying type cannot be used as cupping predictors since no clear trends were observed to classify specialty coffee organoleptic attributes. Therefore, other variables involved in specialty coffee processing should be explored to evaluate higher sensitivity toward flavor prediction and innovation.
Microbiological quality of high-demand food from three major cities in Ecuador
(2021) Salazar Llorente, Enrique Jose; Morales, María; Sornoza Lopez, Ivette Pamela; Maridueña Zavala, María Gabriela; Gu, Ganyu; Nou, Xiangwu; Ortiz Ulloa, Silvia Johana; Maldonado Alvarado, Pedro Gustavo; Cevallos Cevallos, Juan Manuel; Ortiz Ulloa, Silvia Johana
Bacterial foodborne diseases are among the most important public health issues worldwide, but in Ecuador, reports on the microbiological quality of food are scarce. In this cross-sectional study, 450 samples of high-demand Ecuadorian food, including bolon, encebollado, sauces, ceviche, fruit, fruit juice, fruit salad, cheese, raw chicken, and ground beef, were collected from popular street markets in the cities of Guayaquil, Quito, and Cuenca. Populations of total aerobic mesophilic bacteria, total coliforms, fecal coliforms, Escherichia coli, Salmonella enterica, and Listeria monocytogenes were examined on composited samples by plate count following the local regulations (Norma Tecnica Ecuatoriana, Instituto Ecuatoriano de Normalización) for each kind of food. The individual and interaction effects of the city and food type on the levels of each bacterial group were assessed by two-way analysis of variance. Selected colonies from each culture were identified using Biolog OmniLog ID and sequencing of the V3 to V4 region on the 16S rRNA gene. Average total aerobic mesophilic bacteria, total coliform, fecal coliform, and E. coli levels were 5.10 6 0.12, 2.50 6 0.16, 1.09 6 0.12, and 0.83 6 0.12 log CFU/g or mL, respectively, with significant variations among the cities. The prevalence of Salmonella in chicken and sauces and L. monocytogenes in cheese and fruit salad was greater than 20%. Opportunistic pathogens including Klebsiella pneumoniae, Staphylococcus sciuri, and Enterococcus spp. were frequently identified in the samples from all three cities. High prevalence of spoilage microorganisms such as Bacillus amyloliquefaciens and biocontrol bacteria such as Lactococcus lactis was also observed. This is the first report on the microbiological quality of food from Ecuador.
Mortiño (Vaccinium floribundum Kunth): an underutilized superplant from the Andes
(2022) Llivisaca Contreras, Susana Alexandra; León Tamariz, Fabián; Manzano Santana, Patricia Isabel; Ruales Najera, Jeny Cumanda; Naranjo Moran, Jaime Alberto; Serrano Mena, Ana Lissette; Chica Martínez, Eduardo José; Cevallos Cevallos, Juan Manuel
Mortiño is a member of the Ericaceae family native to the Andes that has been used bylocal communities for centuries. This species has shown potential in the areas of medicine, agronomy,and green technology. We used a multidisciplinary approach to review aspects related to the ecology,horticulture, composition and potential biotechnological applications of mortiño. As interest in thisspecies grows, care must be taken to identify opportunities that justify its sustainable use whileemphasizing the development of local communities. Mapping the wide variety of potential uses andthe current state of conservation and utilization of this berry will help researchers to better targetmortiño’s potential
Plants and natural products with activity against various types of coronaviruses: a review with focus on SARS-CoV-2
(2021) Llivisaca Contreras, Susana; Naranjo Morán, Jaime Alberto; Pino Acosta, Andrea; Pieters, Lucas; Vanden Berghe, Wim; Manzano, Patricia; León Tamariz, Fabián; Cevallos Cevallos, Juan Manuel
COVID-19 is a pandemic disease caused by the SARS-CoV-2 virus, which is potentially fatal for vulnerable individuals. Disease management represents a challenge for many countries, given the shortage of medicines and hospital resources. The objective of this work was to review the medicinal plants, foods and natural products showing scientific evidence for host protection against various types of coronaviruses, with a focus on SARS-CoV-2. Natural products that mitigate the symptoms caused by various coronaviruses are also presented. Particular attention was placed on natural products that stabilize the Renin–Angiotensin–Aldosterone System (RAAS), which has been associated with the entry of the SARS-CoV-2 into human cells.
Root endophytic fungi promote in vitro seed germination in Pleurothallis coriacardia (Orchidaceae)
(2020) Maldonado Cedeño, Gabriela Patricia; Cevallos Cevallos, Juan Manuel; Yarzabal Rodríguez, Luis Andrés; Peña Tapia, Denisse Fabiola; Chica Martínez, Eduardo José
Seeds of many orchids rely on the presence of fungi to trigger the germination process and even to initiate the full development of protocorms. While attention has been directed towards the study of mycorrhizal fungi, the diversity and functions of endophytic fungi from orchid roots remain underexplored, and few studies have verified their ecological role. This is the case of Pleurothallis coriacardia, an endemic green Neotropical orchid with both epiphytic and lithophytic habits growing in High-Andean montane forests. In the present study, we screened the cultivable fraction of the endophytic fungi colonizing the roots of mature plants of P. coriacardia using ITS rDNA markers. We also tested the potential of these endophytic fungi to improve embryo development and seed germination. Most of the isolated endophytes were classified within Psathyrellaceae. Some isolates, identified as members of the Ilyonectria and Coprinellus genera, significantly promoted embryo development in vitro in P. coriacardia seeds, a result that highlights the ecological roles these endophytic fungi may play in nature.