Uptake and reduction of Se(IV) in two heterotrophic aerobic Pseudomonads strains isolated from boreal bog environment

Merja Lusa (Corresponding Author), Jenna Knuutinen, Malin Bomberg

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Selenite (Se(IV), SeO 3 2-) uptake and the effect of selenite supplement on protein synthesis was investigated in two Pseudomonas sp. strains isolated from a boreal bog. These aerobic bacteria efficiently reduced Se(IV) with intracellular reduced Se 0 observed in the cytoplasm under dark aerobic conditions. The proteome analysis of Se(IV) supplement and temperature responses by SDS-PAGE gel electrophoresis showed variations in the protein expression on the 40-60 kDa regions following these stress factors, probably through enzymes associated to oxidative stress or temperature adaptation. NO 3 -/NO 2 -/SO 4 2- addition enhanced Se(IV) uptake in both bacteria, but Se(IV) uptake sustained also under sulphur and nitrogen starvation. Our findings suggest two different transport mechanisms for Se(IV) uptake in these Pseudomonas sp. strains; a low affinity transport system up-regulated by NO 3 -/NO 2 -/SO 4 2- and a distinct Se(IV)O 3 2- regulated transport system. Following transport, Se(IV) is reduced in the cytoplasm, forming Se 0 granules, visible in TEM and verified using EDX.

Original languageEnglish
Pages (from-to)798-814
Number of pages17
JournalAIMS Microbiology
Volume3
Issue number4
DOIs
Publication statusPublished - 2017
MoE publication typeA1 Journal article-refereed

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Keywords

  • environmental
  • metabolic processes
  • Pseudomonads
  • soil
  • ecology
  • selenium
  • selenite
  • boreal bog

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