Response to vanadate exposure in Ochrobactrum tritici strains

• Published in: PloS one 2020-02, Vol.15 (2), p.e0229359
• Main Authors: Almeida, Mariana Cruz, Branco, Rita, Morais, Paula V
• Format: Article
• Language: English
• Subjects: Arsenic - pharmacology; Bacteria; Bacterial leaching; Bacterial Proteins - drug effects; Bacterial Proteins - metabolism; Biology and Life Sciences; Chelation; Chromate; Chromates; Chromates - pharmacology; Chromium - pharmacology; Concentrates (ores); Contamination; Cyanobacteria; Drug Resistance, Bacterial - drug effects; Efflux; Exposure; Heavy metals; International economic relations; Iron and steel industry; Leachates; Leaching; Life sciences; Mechanical engineering; Medicine and Health Sciences; Metabolism; Metal industries; Metals; Metals (Materials); Methionine; Microbial Sensitivity Tests; Microorganisms; Minerals; Mining industry; Molecular modelling; Mutants; Ochrobactrum; Ochrobactrum - drug effects; Ochrobactrum - growth & development; Ochrobactrum - metabolism; Ores; Physical Sciences; Proteins; Proteome - drug effects; Proteome - metabolism; RecA protein; Steel industry; Strains (organisms); Superoxide dismutase; Superoxides; Time; Toxicity; Transition metal compounds; Transition metals; Vanadate; Vanadates; Vanadates - pharmacokinetics; Vanadates - pharmacology; Vanadium; Vanadium - pharmacokinetics; Vanadium - pharmacology; Variance analysis
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0229359

Vanadium is a transition metal that has been added recently to the EU list of Raw Critical Metals. The growing needs of vanadium primarily in the steel industry justify its increasing economic value. However, because mining of vanadium sources (i. e. ores, concentrates and vanadiferous slags) is expanding, so is vanadium environmental contamination. Bioleaching comes forth as smart strategy to deal with supply demand and environmental contamination. It requires organisms that are able to mobilize the metal and at the same time are resistant to the leachate generated. Here, we investigated the molecular mechanisms underlying vanadium resistance in Ochrobactrum tritici strains. The highly resistant strain 5bvl1 was able to grow at concentrations > 30 mM vanadate, while the O. tritici type strain only tolerated < 3 mM vanadate concentrations. Screening of O. tritici single mutants (chrA, chrC, chrF and recA) growth during vanadate exposure revealed that vanadate resistance was associated with chromate resistance mechanisms (in particular ChrA, an efflux pump and ChrC, a superoxide dismutase). We also showed that sensitivity to vanadate was correlated with increased accumulation of vanadate intracellularly, while in resistant cells this was not found. Other up-regulated proteins found during vanadate exposure were ABC transporters for methionine and iron, suggesting that cellular responses to vanadate toxicity may also induce changes in unspecific transport and chelation of vanadate.