Browsing by Author "Mandakovic, Dinka"

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    Bacterial communities associated to Chilean altiplanic native plants from the Andean grasslands soils
    (2019) Fernandez-Gomez, Beatriz; Maldonado, Jonathan; Mandakovic, Dinka; Gaete, Alexis; Gutiérrez Ilabaca, Rodrigo Antonio; Maass, Alejandro; Cambiazo, Verónica; González, Mauricio
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    Fungal Diversity Analysis of Grape Musts from Central Valley-Chile and Characterization of Potential New Starter Cultures
    (2020) Mandakovic, Dinka; Pulgar, Rodrigo; Maldonado, Jonathan; Mardones, Wladimir; Gonzalez, Mauricio; Cubillos, Francisco A.; Cambiazo, Veronica
    Autochthonous microorganisms are an important source of the distinctive metabolites that influence the chemical profile of wine. However, little is known about the diversity of fungal communities associated with grape musts, even though they are the source of local yeast strains with potential capacities to become starters during fermentation. By using internal transcribed spacer (ITS) amplicon sequencing, we identified the taxonomic structure of the yeast community in unfermented and fermented musts of a typicalVitis viniferaL. var. Sauvignon blanc from the Central Valley of Chile throughout two consecutive seasons of production. Unsurprisingly,Saccharomycesrepresented the most abundant fungal genus in unfermented and fermented musts, mainly due to the contribution ofS. uvarum(42.7%) andS. cerevisiae(80%). Unfermented musts were highly variable between seasons and showed higher values of fungal diversity than fermented musts. Since microbial physiological characterization is primarily achieved in culture, we isolated nine species belonging to six genera of fungi from the unfermented must samples. All isolates were characterized for their potential capacities to be used as new starters in wine. Remarkably, onlyMetschnikowia pulcherrimacould co-exist with a commercialSaccharomyces cerevisiaestrain under fermentative conditions, representing a feasible candidate strain for wine production.
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    Genome-scale metabolic models of Microbacterium species isolated from a high altitude desert environment
    (2020) Mandakovic, Dinka; Cintolesi, Angela; Maldonado, Jonathan; Mendoza, Sebastian N.; Aite, Meziane; Gaete, Alexis; Saitua, Francisco; Allende, Miguel; Cambiazo, Veronica; Siegel, Anne; Maass, Alejandro; Gonzalez, Mauricio; Latorre, Mauricio
    The Atacama Desert is the most arid desert on Earth, focus of important research activities related to microbial biodiversity studies. In this context, metabolic characterization of arid soil bacteria is crucial to understand their survival strategies under extreme environmental stress. We investigated whether strain-specific features of two Microbacterium species were involved in the metabolic ability to tolerate/adapt to local variations within an extreme desert environment. Using an integrative systems biology approach we have carried out construction and comparison of genome-scale metabolic models (GEMs) of two Microbacterium sp., CGR1 and CGR2, previously isolated from physicochemically contrasting soil sites in the Atacama Desert. Despite CGR1 and CGR2 belong to different phylogenetic clades, metabolic pathways and attributes are highly conserved in both strains. However, comparison of the GEMs showed significant differences in the connectivity of specific metabolites related to pH tolerance and CO2 production. The latter is most likely required to handle acidic stress through decarboxylation reactions. We observed greater GEM connectivity within Microbacterium sp. CGR1 compared to CGR2, which is correlated with the capacity of CGR1 to tolerate a wider pH tolerance range. Both metabolic models predict the synthesis of pigment metabolites (beta -carotene), observation validated by HPLC experiments. Our study provides a valuable resource to further investigate global metabolic adaptations of bacterial species to grow in soils with different abiotic factors within an extreme environment.
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    Intercellular transfer along the trichomes of the invasive terminal heterocyst forming cyanobacterium Cylindrospermopsis raciborskii CS-505
    (2015) Plominsky, Álvaro M.; Delherbe, Nathalie; Mandakovic, Dinka; Riquelme del Río, Brenda Olivia; González, Karen; Bergman, Birgitta; Mariscal, Vincente; Vásquez Pérez, Luz Mónica
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    Partners to survive: Hoffmannseggia doellii root‐associated microbiome at the Atacama Desert
    (2022) Maldonado, Jonathan E.; Gaete, Alexis; Mandakovic, Dinka; Aguado‐Norese, Constanza; Aguilar, Melissa; Gutiérrez Ilabaca, Rodrigo Antonio; González, Mauricio
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    Structure and co-occurrence patterns in microbial communities under acute environmental stress reveal ecological factors fostering resilience
    (2018) Mandakovic, Dinka ; Rojas, Claudia; Maldonado, Jonathan ; Latorre, Mauricio ; Travisany, Dante ; Delage, Erwan ; Bihouée, Audrey ; Díaz, Francisca P. ; Latorre, Claudio ; Navarrete, Sergio A.
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    Testing the stress gradient hypothesis in soil bacterial communities associated with vegetation belts in the Andean Atacama Desert
    (2023) Mandakovic, Dinka; Aguado-Norese, Constanza; García-Jiménez, Beatriz; Hodar, Christian; Maldonado, Jonathan E.; Gaete, Alexis; Latorre, Mauricio; Wilkinson, Mark D.; Gutiérrez Ilabaca, Rodrigo Antonio; Cavieres, Lohengrin A.; Medina, Joaquín; Cambiazo, Verónica; Gonzalez, Mauricio
    Background Soil microorganisms are in constant interaction with plants, and these interactions shape the composition of soil bacterial communities by modifying their environment. However, little is known about the relationship between microorganisms and native plants present in extreme environments that are not affected by human intervention. Using high-throughput sequencing in combination with random forest and co-occurrence network analyses, we compared soil bacterial communities inhabiting the rhizosphere surrounding soil (RSS) and the corresponding bulk soil (BS) of 21 native plant species organized into three vegetation belts along the altitudinal gradient (2400–4500 m a.s.l.) of the Talabre–Lejía transect (TLT) in the slopes of the Andes in the Atacama Desert. We assessed how each plant community influenced the taxa, potential functions, and ecological interactions of the soil bacterial communities in this extreme natural ecosystem. We tested the ability of the stress gradient hypothesis, which predicts that positive species interactions become increasingly important as stressful conditions increase, to explain the interactions among members of TLT soil microbial communities. Results Our comparison of RSS and BS compartments along the TLT provided evidence of plant-specific microbial community composition in the RSS and showed that bacterial communities modify their ecological interactions, in particular, their positive:negative connection ratios in the presence of plant roots at each vegetation belt. We also identified the taxa driving the transition of the BS to the RSS, which appear to be indicators of key host-microbial relationships in the rhizosphere of plants in response to different abiotic conditions. Finally, the potential functions of the bacterial communities also diverge between the BS and the RSS compartments, particularly in the extreme and harshest belts of the TLT. Conclusions In this study, we identified taxa of bacterial communities that establish species-specific relationships with native plants and showed that over a gradient of changing abiotic conditions, these relationships may also be plant community specific. These findings also reveal that the interactions among members of the soil microbial communities do not support the stress gradient hypothesis. However, through the RSS compartment, each plant community appears to moderate the abiotic stress gradient and increase the efficiency of the soil microbial community, suggesting that positive interactions may be context dependent.
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    Tomato Cultivars With Variable Tolerances to Water Deficit Differentially Modulate the Composition and Interaction Patterns of Their Rhizosphere Microbial Communities
    (2021) Gaete, Alexis; Pulgar, Rodrigo; Hodar, Christian; Maldonado, Jonathan; Pavez, Leonardo; Zamorano, Denisse; Pastenes, Claudio; Gonzalez, Mauricio; Franck, Nicolas; Mandakovic, Dinka
    Since drought is the leading environmental factor limiting crop productivity, and plants have a significant impact in defining the assembly of plant-specific microbial communities associated with roots, we aimed to determine the effect of thoroughly selected water deficit tolerant and susceptible Solanum lycopersicum cultivars on their rhizosphere microbiome and compared their response with plant-free soil microbial communities. We identified a total of 4,248 bacterial and 276 fungal different operational taxonomic units (OTUs) in soils by massive sequencing. We observed that tomato cultivars significantly affected the alpha and beta diversity of their bacterial rhizosphere communities but not their fungal communities compared with bulk soils (BSs), showing a plant effect exclusively on the bacterial soil community. Also, an increase in alpha diversity in response to water deficit of both bacteria and fungi was observed in the susceptible rhizosphere (SRz) but not in the tolerant rhizosphere (TRz) cultivar, implying a buffering effect of the tolerant cultivar on its rhizosphere microbial communities. Even though water deficit did not affect the microbial diversity of the tolerant cultivar, the interaction network analysis revealed that the TRz microbiota displayed the smallest and least complex soil network in response to water deficit with the least number of connected components, nodes, and edges. This reduction of the TRz network also correlated with a more efficient community, reflected in increased cooperation within kingdoms. Furthermore, we identified some specific bacteria and fungi in the TRz in response to water deficit, which, given that they belong to taxa with known beneficial characteristics for plants, could be contributing to the tolerant phenotype, highlighting the metabolic bidirectionality of the holobiont system. Future assays involving characterization of root exudates and exchange of rhizospheres between drought-tolerant and susceptible cultivars could determine the effect of specific metabolites on the microbiome community and may elucidate their functional contribution to the tolerance of plants to water deficit.