Differential expression of extracellular thiol groups of moderately thermophilic Sulfobacillus thermosulfidooxidans and extremely thermophilic Acidianus manzaensis grown on S0 and Fe2+

Abstract

Bio-oxidation of elemental sulfur (S(0)) is very important in bioleaching and sulfur cycle. S(0) was proposed to be first activated by reacting with reactive thiol groups (-SH) of outer membrane proteins, forming -S n H (n ≥ 2) complexes. The differential expression of -SH of moderately thermophilic Sulfobacillus thermosulfidooxidans and extremely thermophilic Acidianus manzaensis grown on Fe(2+) and S(0) was investigated by synchrotron radiation-based scanning transmission X-ray microscopy (STXM) imaging and micro-beam X-ray fluorescence (μ-XRF) mapping. The STXM imaging and μ-XRF mapping of extracellular -SH were based on the analysis of Ca(2+) bound on the cell. By comparing Ca(2+) of the cells with and without labeling by Ca(2+), the distribution and content of thiol groups were obtained. The results showed that, for both S. thermosulfidooxidans and A. manzaensis, the expression of extracellular -SH of S(0)-grown cells was higher than that of Fe(2+)-grown cells. Statistical analysis indicated that the expression of extracellular -SH for S. thermosulfidooxidans and A. manzaensis grown on S(0) was 2.37 times and 2.14 times, respectively, to that on Fe(2+). These results evidently demonstrate that the extracellular thiol groups are most probably involved in elemental sulfur activation and oxidation of the acidophilic sulfur-oxidizing microorganisms.

Microbial chemolithotrophic oxidation of pyrite in a subsurface shale weathering environment: Geologic considerations and potential mechanisms

“…Similar models have been described in Acidithiobacillus caldus (Chen et al, 2012; Mangold et al, 2011) and A. thiooxidans (Yin et al, 2014). Interestingly, thiol‐containing OMPs have also been shown to be differentially expressed in phylogenetically distant mesoacidiphilic to extremely acidiphilic sulfur‐oxidizing microorgansims grown on S 0 , including the firmicute Sulfobacillus thermosulfidooxidans and the Archeon Acidianus manzaensis (Liu et al, 2015). While the above studies are restricted to acidophilic taxa, a hypothetical OMP in the neutrophilic ε‐proteobacterial SOB Sulfurimonas denitrificans was recently shown to be enriched in the proteome when the organism was grown on solid‐phase cyclooctasulfur (S 8 ) compared to thiosulfate (Gotz et al, 2019).…”

Correlation Between Fe/S/As Speciation Transformation and Depth Distribution of Acidithiobacillus ferrooxidans and Acidiphilium acidophilum in Simulated Acidic Water Column

“…When 4.5 mM As(III) was added, the composition change of S speciation was similar to the case with 2.0 mM As(III) added, but the promotion effect of sulfur oxidation was lower, while Fe reduction was promoted at the initial experimental stage ( Figure 4C ) and the proportion of Fe(II) began to decrease after day 100. These results indicated that Fe 3+ reduction mediated by glucose or S oxidation occurred as a more likely process at the bottom of the water columns (Eqs 4, 5), with the S 0 opening the ring and activating in contact with the outer membrane protein thiol group (P-SH, where P presents protein) on the cell membrane to form the polysulfide (Eqs 6, 7) ( Rohwerder and Sand, 2003 ; Xia et al, 2013 ; Liu et al, 2015 ). It could be derived that At.…”

<i>In Situ</i> Characterization and Molecular Mechanisms Evaluation of Interfacial Interaction between Minerals and Bioleaching Microorganisms

“…Based on comparative proteomics study and qRT-PCR analysis of the relevant protein-coded genes, and in-situ analysis of the cell surface -SH groups by synchrotron radiation-based STXM, μ-XRF, we found that the expression of all selected sulfur-activation relevant protein genes and the quantities of cell surface -SH groups of the SOMs growing on S 0 were higher than that on Fe 2+ [14][15][16]. It suggests that the different environmental temperature adapted SOMs might have different utilization mechanism for μ-S and α-S 8 , but their activation mechanism might be similar…”