Departamento de Biotecnología

URI permanente para esta colección

http://repositorioabierto.uantof.cl/handle/uantof/231

Examinar

Mostrando 1 - 12 de 12

Complete genome sequence of Cellulomonas sp. strain ATA003
(2024) Alexander Bartholomäus; Julia Mitzscherling; Daniel Lipus; Dirk Wagner; Paris Lavin; Roberto Contreras; Rómulo Oses
The Gram-positive, rod-shaped endophytic bacterium Cellulomonas sp.strain ATA003 was isolated from the endemic cactus Maihueniopsis domeykoensis seeds collected in the Coastal Atacama Desert, Chile. Here, we present a circular genome with a size of 4,084,881 bp and a GC content of 73.8% obtained by Nanopore sequencing.
Differences in the adulteration degree and antimicrobial activity of chilean ulmo honey versus multifloral honey revealed by stable isotope analysis
(2024) Pablo Pérez; Paris Lavín; Chris Harrod; Pedro Echeveste
Honey, valued for its nutritional and antimicrobial benefits, has experienced an increased production in recent decades. However, this rise has been accompanied by concerns of adulteration, often involving the fraudulent addition of sugars. Our study sought to compare the physicochemical and isotopic properties of various honeys available to Chilean consumers, assessing the extent of adulteration. Samples included honey produced from bees that fed on multiple flowers and those fed by ulmo flowers – an endemic species of South America that produces a high-quality, high-cost honey – and analyzed for antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The analysis of ash content (%), moisture (%), pH and total phenolic content (mg GAE/100 g honey) found little obvious differences among honeys regardless of the feeding flowers (multifloral vs ulmo), type of purchase market (formal vs informal) or origin of the honeys (Central vs Southern Chile). However, the use of stable isotope analysis (δ 13 C and δ 15 N) of honey provided a powerful means to identify the degree of adulteration prior to the point of sale. Multifloral honeys purchased at informal markets were all adulterated, and ulmo honeys included both the least and most adulterated honeys. Regarding their antimicrobial activity, most multifloral honeys were less effective than ulmo honeys. Notably, while multifloral honey activity was independent of adulteration, the antimicrobial activity of ulmo honey was negatively affected by adulteration.
First screening of bacteria assemblages associated with the marine polychaete Melinna palmata Grube, 1870 and adjacent sediments
(2024) Selma Menabit; Paris Lavin; Tatiana Begun; Mihaela Muresan; Adrian Teaca; Cristina Purcarea
Bacteria associated with marine invertebrate play a fundamental role in the biology, ecology, development and evolution of their hosts. Although many studies have been focused on the microbial populations of benthic and pelagic habitats, little is known about bacteria colonizing tube-dwelling polychaete. In this context, the current study provided the first characterization of the Melinna palmata Grube, 1870 microbiome based on Illumina sequencing of 16S rRNA gene of the polychaete tissue and proximate sediments collected from the Black Sea, Romania, along a 24.2 m - 45.4 m depth-gradient. The diversity, taxonomic composition and deduced functional profile of the tissue and sediments associated bacterial communities were compared and analyzed in relation with the environmental parameters. This polychaete harbored a distinct bacterial assemblage as compared to their sediments and independent on the depth of their habitat, including 8 phyla in tissues dominated by Proteobacteria, and 12 phyla in sediments majorly represented by Actinobacteriota, respectively. At order level, Synechococcales, Rhodobacterales and Actinomarinales were highly represented in the M. palmata microbiome, while Microtrichales, Anaerolineales and Caldilineales were mostly found in sediments. A significant correlation was observed between Cyanobacteria taxa and the dissolved oxygen concentrations in shallow waters impacted by the Danube inputs. Meanwhile, this phylum showed a positive correlation with Planctomycetota colonizing the invertebrate tissues, and a negative one with Actinobacteriota and Chloroflexi found in sediments. The deduced functional profile of these bacterial assemblages suggested the prevalence of the amino acid and carbohydrate metabolism for both analyzed matrices. This pioneering report on the M. palmata microbiome highlighted the environment contribution to bacterial species enrichment of the polychaete, and provided a glimpse on the putative role of microbial communities associated with this marine organism.
Inactivated Vaccine-Induced SARS-CoV-2 Variant-SpeciﬁcImmunity in Children
(2022) Jorge A. Soto; Felipe Melo González; Cristián Gutierrez Vera; Bárbara M. Schultz; Roslye V. Berríos Rojas; Daniela Rivera Pérez; Alejandro Piña Iturbe; Guillermo Hoppe Elsholz; Luisa F. Duarte; Yaneisi Vázquez; Daniela Moreno Tapia; Mariana Ríos; Pablo A. Palacios; Richard Garcia Betancourt; Álvaro Santibañez; Gaspar A. Pacheco; Constanza Mendez; Catalina A. Andrade; Pedro H. Silva; Benjamín Diethelm Varela; Patricia Astudillo; Mario Calvo; Antonio Cárdenas; Marcela González; Macarena Goldsack; Valentina Gutiérrez; Marcela Potin; Andrea Schilling; Lorena I. Tapia; Loreto Twele; Rodolfo Villena; Alba Grifoni; Alessandro Sette; Daniela Weiskopf; Rodrigo A. Fasce; Jorge Fernández; Judith Mora; Eugenio Ramírez; Aracelly Gaete Argel; Mónica L. Acevedo; Fernando Valiente Echeverría; Ricardo Soto Rifo; Angello Retamal Díaz; Nathalia Muñoz Jofré; PedCoronaVac03CL Study Group; Xing Meng; Qianqian Xin; Eduardo Alarcón Bustamante; José V. González Aramundiz; Nicole Le Corre; María Javiera Álvarez Figueroa; Pablo A. González; Katia Abarca; Cecilia Perret; Leandro J. Carreño; Susan M. Bueno; Alexis M. Kalergis
Multiple vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been evaluated in clinical trials. However, trials addressing the immune response in the pediatric population are scarce. The inactivated vaccine CoronaVac has been shown to be safe and immunogenic in a phase 1/2 clinical trial in a pediatric cohort in China. Here, we report interim safety and immunogenicity results of a phase 3 clinical trial for CoronaVac in healthy children and adolescents in Chile. Participants 3 to 17 years old received two doses of CoronaVac in a 4-week interval until 31 December 2021. Local and systemic adverse reactions were registered for volunteers who received one or two doses of CoronaVac. Whole-blood samples were collected from a subgroup of 148 participants for humoral and cellular immunity analyses. The main adverse reaction reported after the first and second doses was pain at the injection site. Four weeks after the second dose, an increase in neutralizing antibody titer was observed in subjects relative to their baseline visit. Similar results were found for activation of specific CD41 T cells. Neutralizing antibodies were identified against the Delta and Omicron variants. However, these titers were lower than those for the D614G strain. Importantly, comparable CD41 T cell responses were detected against these variants of concern. Therefore, CoronaVac is safe and immunogenic in subjects 3 to 17 years old, inducing neutralizing antibody secretion and activating CD41 T cells against SARS-CoV-2 and its variants. (This study has been registered at ClinicalTrials .gov under no. NCT04992260.)
New insights into the pathogenesis of SARS-CoV-2 during and after the COVID- 19 pandemic
(2024) Jonatan J. Carvajal; Valeria García Castillo; Shelsy V. Cuellar; Claudia P. Campillay Véliz; Camila Salazar Ardiles; Andrea M. Avellaneda; Christian A. Muñoz; Angello Retamal Díaz; Susan M. Bueno; Pablo A. González; Alexis M. Kalergis; Margarita K. Lay
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the respiratory distress condition known as COVID-19. This disease broadly affects several physiological systems, including the gastrointestinal, renal, and central nervous (CNS) systems, significantly influencing the patient’s overall quality of life. Additionally, numerous risk factors have been suggested, including gender, body weight, age, metabolic status, renal health, preexisting cardiomyopathies, and inflammatory conditions. Despite advances in understanding the genome and pathophysiological ramifications of COVID-19, its precise origins remain elusive. SARS-CoV-2 interacts with a receptor-binding domain within angiotensin-converting enzyme 2 (ACE2). This receptor is expressed in various organs of different species, including humans, with different abundance. Although COVID-19 has multiorgan manifestations, the main pathologies occur in the lung, including pulmonary fibrosis, respiratory failure, pulmonary embolism, and secondary bacterial pneumonia. In the post- COVID-19 period, different sequelae may occur, which may have various causes, including the direct action of the virus, alteration of the immune response, and metabolic alterations during infection, among others. Recognizing the serious adverse health effects associated with COVID-19, it becomes imperative to comprehensively elucidate and discuss the existing evidence surrounding this viral infection, including those related to the pathophysiological effects of the disease and the subsequent consequences. This review aims to contribute to a comprehensive understanding of the impact of COVID-19 and its long-term effects on human health.
Protist communities of microbial mats from the extreme environments of five saline Andean lagoons at high altitudes in the Atacama Desert
(2024) Eduardo Acosta; Frank Nitsche; Cristina Dorador; Hartmut Arndt
Introduction:Heterotrophic protists colonizing microbial mats have received little attention over the last few years, despite their importance in microbial food webs. A significant challenge originates from the fact that many protists remain uncultivable and their functions remain poorly understood.Methods:Metabarcoding studies of protists in microbial mats across high-altitude lagoons of different salinities (4.3–34 practical salinity units) were carried out to provide insights into their vertical stratification at the millimeter scale. DNA and cDNA were analyzed for selected stations.Results:Sequence variants classified as the amoeboid rhizarian Rhogostoma and the ciliate Euplotes were found to be common members of the heterotrophic protist communities. They were accompanied by diatoms and kinetoplastids.Correlation analyses point to the salinity of the water columnas a main driver influencing the structure of the protist communities at the five studied microbial mats. The active part of the protist communities was detected to be higher at lower salinities (<20 practical salinity units).Discussion:We found a restricted overlap of the protist community between the different microbial mats indicating the uniqueness of these different aquatic habitats. On the other hand, the dominating genotypes present in metabarcoding were similar and could be isolated and sequenced in comparative studies(Rhogostoma, Euplotes,Neobodo). Our results provide a snapshot of the unculturable protist diversity thriving the benthic zone of ive athalossohaline lagoons across the Andean plateau.
Response to static magnetic field-induced stress in scenedesmus obliquus and nannochloropsis gaditana
(2021) Génesis Serrano; Carol Miranda-Ostoijc; Pablo Ferrada; Cristian Wulff-Zotelle; Alejandro Maureira; Edward Fuentealba; Karem Gallardo; Manuel Zapata; Mariella Rivas
Magnetic fields in biological systems is a promising research field; however, their application for microalgae has not been fully exploited. This work aims to measure the enzymatic activity and non-enzymatic activity of two microalgae species in terms of superoxide dismutase (SOD), catalase (CAT), and carotenoids, respectively, in response to static magnetic fields-induced stress. Two magnet configurations (north and south) and two exposure modes (continuous and pulse) were applied. Two microalgae species were considered, the Scenedesmus obliquus and Nannochloropsis gaditana. The SOD activity increased by up to 60% in S. obliquus under continuous exposure. This trend was also found for CAT in the continuous mode. Conversely, under the pulse mode, its response was hampered as the SOD and CAT were reduced. For N. gaditana, SOD increased by up to 62% with the south configuration under continuous exposure. In terms of CAT, there was a higher activity of up to 19%. Under the pulsed exposure, SOD activity was up to 115%. The CAT in this microalga was increased by up to 29%. For N. gaditana, a significant increase of over 40% in violaxanthin production was obtained compared to the control, when the microalgae were exposed to SMF as a pulse. Depending on the exposure mode and species, this methodology can be used to produce oxidative stress and obtain an inhibitory or enhanced response in addition to the significant increase in the production of antioxidant pigments.
Secondary metabolites with antimicrobial activity produced by thermophilic bacteria from a high-altitude hydrothermal system
(2024) Coral Pardo Esté; Johanna Cortés; Juan Castro Severyn; Vilma Pérez; Karem Henriquez Aedo; Fabian Cuadros; Carolina Yañez; Sara Cuadros Orellana; Cristina Dorador; Veronica Molina; Yoanna Eissler; Pablo Paquis; Wade H. Jeffrey; Patricia Pozo; Pablo A. Pérez; Martha B. Hengst
Thermophilic microorganisms possess several adaptations to thrive in high temperature, which is reflected as biosynthesis of proteins and thermostable molecules, isolation and culture represent a great methodological challenge, therefore High throughput sequencing enables screening of the whole bacterial genome for functional potential, providing rapid and cost-effective information to guide targeted cultures for the identification and characterization of novel natural products. In this study, we isolated two thermophilic bacterial strains corresponding to Bacillus LB7 and Streptomyces LB8, from the microbial mats in the Atacama Desert. By combining genome mining, targeted cultures and biochemical characterization, we aimed to identify their capacity to synthesize bioactive compounds with antimicrobial properties. Additionally, we determined the capability to produce bioactive compounds under controlled in vitro assays and detected by determining their masses by Thin-Layer Chromatography/Mass Spectrometry (TLC/MS). Overall, both isolates can produce antimicrobial (e.g., Myxalamide C by-product) and antioxidants (e.g. Dihydroxymandelic Acid, Amide biotine and Flavone by-products) compounds. Bacillus LB7 strain possesses a more diverse repertoire with 51.95% of total metabolites unmatched, while Streptomyces LB8 favors mainly antioxidants, but has over 70% of unclassified compounds, highlighting the necessity to study and elucidate the structure of novel compounds. Based on these results, we postulate that the uncultured or rare cultured thermophiles inhabiting high-altitude hydrothermal ecosystems in the Atacama Desert offer a promising opportunity to the study of novel microbial bioactive compounds.
Shared governance in the plant holobiont and implications for one health
(2024) Gabriele Berg; Cristina Dorador; Dilfuza Egamberdieva; Joel E. Kostka; Choong-Min Ryu; Birgit Wassermann
The holobiont Holobiont theory is more than 80 years old, while the importance of microbial communities for plant holobionts was already identified by Lorenz Hiltner more than a century ago. Both concepts are strongly supported by results from the new field of micr obiome r esear c h. Here , w e present ecolog ical and g enetic featur es of the plant holobiont that underpin principles of a shar ed governance between hosts and microbes and summarize the relevance of plant holobionts in the context of global c hange . Moreover, we unco ver kno wledge gaps that arise when inte gr ating plant holobionts in the broader perspective of the holobiome as well as one and planetary health concepts. Action is needed to consider interacting holobionts at the holobiome scale, for prediction and control of microbiome function to improve human and environmental health outcomes.
Sulfate Nutrition Modulates the Oxidative Response against Short-Term Al3+-Toxicity Stress in Lolium perenne cv. Jumbo Shoot Tissues
(2024) Hernan Vera Villalobos; Lizzeth Lunario Delgado; Anita S. Gálvez; Domingo Román Silva; Ana Mercado Seguel; Cristián Wulff Zottele
Al3+-toxicity in acidic soils is among the main abiotic stress factors that generate adverse effects in plant growth; in leaves, it affects several physiological parameters such as photosynthesis and ROS balance, leading to limited crop production. On the other hand, sulfur is a macronutrient that has a key role against oxidative stress and improves plant growth in acidic soils; however, the implication of sulfate nutritional status in the modulation of short-term Al3+-toxicity tolerance mechanisms in plant leaves are barely reported. This study is focused on the role of sulfate on the leaf response of an Al3-sensitive perennial ryegrass (Lolium perenne cv. Jumbo) after 48 h of exposure. Lolium perenne cv. Jumbo seeds were cultivated in hydroponic conditions with modified Taylor Foy solutions supplemented with 120, 240, and 360 μM sulfate in the presence or absence of Al3+-toxicity. The L. perenne cv. Jumbo leaves were collected after 48 h of Al3+-toxicity exposure and processed to evaluate the effects of sulfate on Al3+ toxicity, measuring total proteins, mineral uptake, photosynthesis modulation, and ROS defense mechanism activation. The plants exposed to Al3+-toxicity and cultivated with a 240 μM sulfate amendment showed a recovery of total proteins and Ca2+ and Mg2+ concentration levels and a reduction in TBARS, along with no changes in the chlorophyll A/B ratio, gene expression of proteins related to photosynthesis (Rubisco, ChlAbp, and Fered), or ROS defense mechanism (SOD, APX, GR, and CAT) as compared with their respective controls and the other sulfate conditions (120 and 360 μM). The present study demonstrates that adequate sulfate amendments have a key role in regulating the physiological response against the stress caused by Al3+ toxicity.
The Chilean COVID-19 Genomics Network Biorepository: A Resource for Multi-Omics Studies of COVID-19 and Long COVID in a Latin American Population
(2024) Iskra A. Signore; Gerardo Donoso; Pamela Bocchieri; Eduardo A. Tobar-Calfucoy; Cristian E. Yáñez; Laura Carvajal-Silva; Andrea X. Silva; Carola Otth; Claudio Cappelli; Héctor Valenzuela Jorquera; Daniela Zapata Contreras; Yolanda Espinosa Parrilla; Paula Zúñiga Pacheco; Macarena Fuentes Guajardo; Virginia A. Monardes Ramírez; Pia Kochifas Velasquez; Christian A. Muñoz; Cristina Dorador; Jonathan García Araya; Claudia P. Campillay Véliz; Cesar Echeverria; Rodolfo Alejandro Santander; Leslie C. Cerpa; Matías F. Martínez; Luis Abel Quiñones; Eduardo Roberto Lamoza Galleguillos; Juan Saez Hidalgo; Estefanía Nova-Lamperti; Sergio Sanhueza; Annesi Giacaman; Gerardo Acosta Jamett; Cristóbal Verdugo; Anita Plaza; Claudio Verdugo; Carolina Selman; Ricardo Alejandro Verdugo; Alicia Colombo
Although a lack of diversity in genetic studies is an acknowledged obstacle for personalized medicine and precision public health, Latin American populations remain particularly understudied despite their heterogeneity and mixed ancestry. This gap extends to COVID-19 despite its variability in susceptibility and clinical course, where ethnic background appears to influence disease severity, with non-Europeans facing higher hospitalization rates. In addition, access to high-quality samples and data is a critical issue for personalized and precision medicine, and it has become clear that the solution lies in biobanks. The creation of the Chilean COVID-19 Biorepository reported here addresses these gaps, representing the first nationwide multicentric Chilean initiative. It operates under rigorous biobanking standards and serves as one of South America’s largest COVID cohorts. A centralized harmonization strategy was chosen and included unified standard operating procedures, a sampling coding system, and biobanking staff training. Adults with confirmed SARS-CoV-2 infection provided broad informed consent. Samples were collected to preserve blood, plasma, buffy coat, and DNA. Quality controls included adherence to the standard preanalytical code, incident reporting, and DNA concentration and absorbance ratio 260/280 assessments. Detailed sociodemographic, health, medication, and preexisting condition data were gathered. In five months, 2262 participants were enrolled, pseudonymized, and sorted by disease severity. The average Amerindian ancestry considering all participant was 44.0% [SD 15.5%], and this value increased to 61.2% [SD 19.5%] among those who self-identified as Native South Americans. Notably, 279 participants self-identified with one of 12 ethnic groups. High compliance (>90%) in all assessed quality controls was achieved. Looking ahead, our team founded the COVID-19 Genomics Network (C19-GenoNet) focused on identifying genetic factors influencing SARS-CoV-2 outcomes. In conclusion, this bottom-up collaborative effort aims to promote the integration of Latin American populations into global genetic research and welcomes collaborations supporting this endeavor. Interested parties are invited to explore collaboration opportunities through our catalog, accessible online.
Whole-genome sequencing of a Janthinobacterium sp. isolatedfrom the Patagonian Desert
(2024) Nicole T. Cavanaugh; Girish Kumar; Alicyn Reverdy Pearson; Julia Colbert; Carlos Riquelme; André O. Hudson; Yunrong Chai; Veronica Godoy Carter
Janthinobacterium is a genus of Gram-negative environmental bacteria that survive extreme conditions by forming biofilms and producing pigments. Janthinobacterium sp. LS2A, an extremophile isolated from soil in the Chilean Patagonia, contains seven known biosynthetic gene clusters, including the purple pigment violacein, which may aid in its survival in harsh environments.

Examinar

Examinando Departamento de Biotecnología por Título

Resultados por página

Opciones de ordenación