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ORIGINAL RESEARCH article

Front. Microbiol.
Sec. Extreme Microbiology
Volume 15 - 2024 | doi: 10.3389/fmicb.2024.1369244
This article is part of the Research Topic Acidophile Microbiology: From Extreme Environments to Biotechnological Applications View all 18 articles

Osmotic response in Leptospirillum ferriphilum isolated from an industrial copper bioleaching environment to sulfate

Provisionally accepted
Dayana N. Arias Dayana N. Arias 1Víctor Zepeda Víctor Zepeda 2Manuel Saldaña Manuel Saldaña 3Ivan Nancucheo Ivan Nancucheo 4Pedro A. Galleguillos Pedro A. Galleguillos 2*
  • 1 University of Antofagasta, Antofagasta, Chile
  • 2 Centro de Investigación Científico y Tecnológico para la Minería (CICITEM), Antofagasta, Chile
  • 3 Arturo Prat University, Iquique, Chile
  • 4 Faculty of Engineering and Technology, San Sebastián University, Santiago, Santiago Metropolitan Region (RM), Chile

The final, formatted version of the article will be published soon.

    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/ionizationtime 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.

    Keywords: bioleaching, compatible solutes, Lesptospirillum ferriphilum, Osmotic strength, sulfate

    Received: 11 Jan 2024; Accepted: 08 May 2024.

    Copyright: © 2024 Arias, Zepeda, Saldaña, Nancucheo and Galleguillos. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Pedro A. Galleguillos, Centro de Investigación Científico y Tecnológico para la Minería (CICITEM), Antofagasta, Chile

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