Fig. 3From: 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?Pictorial overview of the concepts that emerged from the discussion. The cartoon reflects a Gram-negative cell with outer membrane (OM), periplasmic space, and inner membrane (IM), although many of the processes will be the same or similar in Gram-positives. Note: this is a generalized scheme, and the depicted processes may occur differently in different species/strains and growth conditions based on the bioenergetics of their systems. Question marks (?) indicate reactions or biochemical mechanisms not yet clarified, require more experimental support and/or not in agreement. Equations are simplified and are not defined stoichiometrically. See text for further details. Ch, stands for chalcogen metalloid, either selenium or tellurium, unless specifically indicated; GSH, reduced glutathione; CISM, complex iron-sulfur molybdoenzyme; TrxA, thrioredoxin; TrxB, thrioredoxin reductase; Grx, glutaredoxin; Gor, glutathione reductase; ndh-II, NADH:quinone oxidoreductase II; Icd, isocitrate dehydrogenase; Lpd, lipoamide dehydrogenase; Ahp, hydroperoxide reductase; norW, NADH:flavorubredoxin; Ccm, cytochrome C maturation; CydDC, glutathione/cysteine exporter; CysIJ, sulfite reductase; Pit, phosphate importers; SuT, sulfate transporters; Mphor, Metallophore/Siderophore; pmf, proton motive force; QH2, reduced quinone; Laws, Lawsone; e-, electrons; GSH, reduced glutathione; GSSG, oxidized glutathione; RSH or -SH, thiol-group containing compounds or amino acids; ROS, reactive oxygen species; NP. Coloration of the nanomaterials: orange or black is elemental Se or Te, respectively; red outline indicates cytoplasmic biomolecular coating; light blue is to suggest a lipid and/or EPS coating; pink coating to the Te rods to suggest a biosurfactant coating Back to article page