Skip to main content

Table 3 Formation of reactive oxygen species (ROS) in various bacterial species when exposed to selenite and tellurite

From: Tellurite and Selenite: how can these two oxyanions be chemically different yet so similar in the way they are transformed to their metal forms by bacteria?

Bacterial species Experimental procedures
(metalloid)
Results observed Refs.
Selenite    
 E. coli 2D-electrophoresis of soluble and membrane fractions from cell extracts SOD induction but only in cells grown aerobically in the presence of selenite [89]
 E. coli Construction of mutants (ΔsodA, ΔsodB, ΔtrxA, ΔtrxB, Δgor, ΔgshA) Strains lacking either sodA or sodB were hypersensitive to selenite. Deletions of either trxA, trxB, gor, and gshA had no effect on selenite sensitivity [89]
 E. coli In vivo use of the fluorescent ROS-sensitive probe DCFH-DA after exposure to selenite Strong increase of fluorescence in cells exposed to selenite [48]
Tellurite
 R. capsulatus Non-denaturing PAGE of lysates from cells treated with tellurite (or paraquat) Strong increase of SOD activity in cells treated with tellurite (or paraquat) [97]
 E. coli, S. epidermidis Construction of mutants
(ΔkatG)
A katG minus mutant was hypersentive to tellurite; expression of kat gene of S.epidermis in E.coli increases in the latter resistance to tellurite [138]
 E. coli Use of the fluorescent ROS-sensitive probe DCFH-DA in extracts of cells exposed to tellurite Increase of the fluorescence as a function of tellurite concentration [155]
 E. coli DNA fragments amplification of genes (sodA, sodB, katG, soxS, gapA) Increase of sodA and sodB with a strong induction of katG and soxS mRNA synthesis in the presence of tellurite [155]
 Pseudomonas pseudoalcaligenes In vivo use of the fluorescent ROS-sensitive probe DCFH-DA after exposure to tellurite Strong increase of fluorescence in cells exposed to tellurite [103]
  1. DCFH-DA, dichloro-dihydro-fluorescein diacetate; SOD, superoxide dismutase; PAGE, polyacrylamide gel electrophoresis. Genes: gapA, glyceraldeide-3-phosphate dehydrogenase A; gor, glutathione reductase; sodA and sodB, superoxide dismutase A and B; soxS, regulatory protein in E.coli; trxA and trxB, thioredoxin reductases. Bacterial species: E.coli, Escherichia coli, R. capsulatus, Rhodobacter capsulatus, R. sphaeroides, Rhodobacter sphaeroides,
  2. S. epidermidis, Staphylococcus epidermidis