Examinando por Autor "Dayana Arias"

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    Ítem
    Osmotic response in Leptospirillum ferriphilum isolated from an industrial copper bioleaching environment to sulfate
    (2024) Dayana Arias; Víctor Zepeda; Ivan Nancucheo; Manuel Saldaña; Pedro A. Galleguillos
    Iron and sulfur-oxidizing microorganisms play important roles in several natural and industrial processes. Leptospirillum (L.) ferriphilum, is an iron-oxidizing microorganism with a remarkable adaptability to thrive in extreme acidic environments, including heap bioleaching processes, acid mine drainage (AMD) and natural acidic water. A strain of L. ferriphilum (IESL25) was isolated from an industrial bioleaching process in northern Chile. This strain was challenged to grow at increasing concentrations of sulfate in order to assess changes in protein expression profiles, cells shape and to determine potential compatible solute molecules. The results unveiled changes in three proteins: succinyl CoA (SCoA) synthetase, isocitrate dehydrogenase (IDH) and aspartate semialdehyde dehydrogenase (ASD); which were notably overexpressed when the strain grew at elevated concentrations of sulfate. ASD plays a pivotal role in the synthesis of the compatible solute ectoine, which was identified along with hydroxyectoine by using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF). The relationship between IDH, SCoA, and ectoine production could be due to the TCA cycle, in which both enzymes produce metabolites that can be utilized as precursors or intermediates in the biosynthesis of ectoine. In addition, distinct filamentous cellular morphology in L. ferriphilum IESL25 was observed when growing under sulfate stress conditions. This study highlights a new insight into the possible cellular responses of L. ferriphilum under the presence of high sulfate levels, commonly found in bioleaching of sulfide minerals or AMD environments.
  • Miniatura
    Ítem
    Uncovering Hidden Microbial Diversity in Nitrate/Iodide Deposits (NIDs) in the Domeyko District, Atacama Desert, Chile
    (2024) Mayra Cortés; Priscilla Avendaño; Olga Encalada; Camila Salazar Ardiles; David C. Andrade; Benito Gómez Silva; Daniel Contreras; Norman Toro; Dayana Arias; Lorena V. Escudero
    Unique worldwide, nitrate/iodine deposits (NIDs) are located along a 700 km geological belt in the Atacama Desert, Chile. They serve as the primary source of mineral ores for the extraction of iodine, sodium, and potassium nitrates. NIDs have been relatively underexplored from a biological perspective. To address this, we collected sixteen soil samples from abandoned mines in Oficinas Pissis and Savona for chemical, mineralogical, and metagenomic analyses. The soils primarily consisted of halite and darapskite, with only one sample being predominantly composed of thenardite. Deliquescence and water activity measurements yielded values ranging from 0.02% to 0.40% and 0.47 to 0.62, respectively. To investigate the presence, identification, relative abundance, and diversity of microbial life in NID soils, we employed MiSeq high-throughput sequencing and bioinformatic tools. The dominant phyla observed were Firmicutes and Proteobacteria, with Actinobacteria and Cyanobacteria being predominant in two soil samples. Furthermore, we detected nitrate/perchloratereducing bacterial activity in enriched cultures from the soil samples. This study sheds light on the resilience of microbial life in the Atacama Desert NIDs, providing compelling evidence for its existence and offering insight into factors that could facilitate it within this unique environment.