Tellurite Adsorption onto Bacterial Surfaces

Abstract

Tellurium (Te) is an emerging contaminant and its chemical transformation in the environment is strongly influenced by microbial processes. In this study, we investigated the adsorption of tellurite [Te(IV), TeO 3 2−] onto the common soil bacterium Bacillus subtilis. Thiol-blocking experiments were carried out to investigate the role of cell surface sulfhydryl sites in tellurite binding, and extended X-ray absorption fine structure (EXAFS) spectroscopy was performed to determine the chemical speciation of the adsorbed tellurite. The results indicate that tellurite reacts with sulfhydryl functional groups in the extracellular polymeric substances (EPS) produced by B. subtilis. Upon binding to sulfhydryl sites in the EPS, the Te changes from Te−O bonds to Te−S coordination. Further analysis of the surface-associated molecules shows that the EPS of B. subtilis contain proteins. Removal of the proteinaceous EPS dramatically decreases tellurite adsorption and the sulfhydryl surface site concentration. These findings indicate that sulfhydryl binding in EPS plays a key role in tellurite adsorption on bacterial surfaces.

Effective adsorption of perrhenate ions on the filamentous sheath-forming bacteria, Sphaerotilus montanus, Sphaerotilus natans and Thiothrix fructosivorans

“…This mechanism explains the decrease of the adsorption with the pH (Figure 4). The reduction-induced oxyanion adsorption (Goff et al, 2021;Yu et al, 2018) is a possible mechanism, which is consistent with the presence of Re(VI) on the surface (Figure S1). In this mechanism, a surface thiol is covalently bound with the cationic element of the oxyanion substituting oxygen.…”

“…For all the adsorbents, about 60% is attributed to heptavalent rhenium, implying that the anion is reduced by adsorption. The reduction of selenate and tellurate occurs by the adsorption on bacterial surfaces (Goff et al, 2021; Yu et al, 2018). The reaction is induced by the bond formation with two vicinal thiol sites.…”

Anaerobic self-assembly of a regenerable bacteria-quantum dot hybrid for solar hydrogen production

“…4f), thus enabling more efficient and directional bioconversion of the precursors towards bio-QD formation. 38,39 The anaerobically stimulated uptake and reduction of Se by the cells were supported by metal content analysis (Fig. 4e), which showed a similar Cd content but a 3.5-fold higher Se content of the bio-hybrid under anaerobic conditions over aerobic conditions after 4 h incubation.…”

Tolerance, Adaptation, and Cell Response Elicited by Micromonospora sp. Facing Tellurite Toxicity: A Biological and Physical-Chemical Characterization

“…The importance of polysaccharide variations also arose from PCA analysis, in which the vector describing these contributions distinguished unchallenged cells from those challenged ( Figure 7 ). Interestingly, Goff and coworkers (2021) recently reported that sulfhydryl groups of the proteinaceous material within EPS of Bacillus subtilis play a crucial role in binding TeO 3 2− , mediating its sorption on bacterial surfaces [ 76 ]. At this stage, it cannot be ruled out that sulfhydryl groups in the EPS of Micromonospora EPS could bind TeO 3 2− to limit its translocation into the cell cytoplasm.…”

“…However, a direct comparison between the profiles describing RSH depletion in Micromonospora growing cells with the available literature is challenging, as most studies focused on the earliest stages (up to 2.5-h) of either bacterial growth or exposure to this oxyanion. In the case of Micromonospora growing cells, RSH depletion may rely on (i) RSH groups within EPS binding with TeO 3 2− [ 76 ], (ii) Painter-type reactions, (iii) ROS detoxification [ 84 ], and (iv) the modification of RSH-rich proteins caused by oxidative stress [ 27 ]. Hypotheses (i–iii) were sustained by the detection of vibrational modes attributable to RSH-, thiolate (RS − )-, and disulfide (RSSR)-containing molecules ( Figure 6 b,c; Table S1 ).…”