The preferential oxidation of orthorhombic sulfur during batch culture

Abstract

The formation of sulfur is predicted by the current understanding of the mechanisms involved in mineral sulfide oxidation and observed in studies of the leaching products that accumulate on the surface of the mineral. Sulfur oxidising bacteria can exploit this energy source and can remove a potentially 'rate-limiting' diffusion barrier. In this study on the activity of sulfur oxidising bacteria cultured on mixed solid sulfur allotropes, it was observed that a heterogeneous culture preferentially oxidised the orthorhombic allotrope and no significant growth on the polymeric allotrope could be demonstrated.

Bioelectrochemical Changes during the Early Stages of Chalcopyrite Interaction with Acidithiobacillus Thiooxidans and Leptospirillum sp.

“…According to Rohwerder et al [25] and Yin et al [26], the activation of S 0 from cyclic to linear RSS proceeds via a nucleophilic attack of glutathione (GSH) and sulfonate (-SH) groups found in the outer-membrane protein of SOM. We hypothesize that Fe ions also favor such activation of the linear structures (Figure 5a), as the results of this and other works suggested, as well as the Hard-Soft Acid Base Theory studies on solid sulfur allotropes and sulfur oxidation [15,[26][27][28][29][30][31][32][33]. This hypothesis should be proved and it is the subject of our future work.…”

“…Thus, Fe 3+ may induce a S 0 -Fe 3+ complex formation and/or (iv-vi) charge delocalization, until it rises to a linear S n 2− that interacts with the GS − to form GS-S n H, available for SOM, as already mentioned (iii). Agglomerated reduced sulfur species (RSS) (b) and thin and spongy layer (c) after SOM and SOM+IOM biooxidation of MCE*, respectively [15,29,30,32,33].…”

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

“…It is worthy to note that utilization of sulfur by ASOMs is quite different not only between different sulfur allotropes but also between mesophiles and thermophiles (Blight et al 2009;Briand et al 1999;Liu et al 2013). According to the previous description based on the differential utilization and sulfur speciation transformation analysis of two S 0 allotropes, α-S 8 and μ-S, by mesophilic A. ferrooxidans, moderately thermophilic S. thermosulfidooxidans and extremely thermophilic A. manzaensis Nie et al 2014;Peng et al 2014), it is evident that μ-S is more easily bio-adapted and activated than α-S 8 by all the three species, but sulfur speciation transformation between μ-S and α-S 8 was quite different between the thermophiles and the mesophile.…”

Differential utilization and transformation of sulfur allotropes, μ-S and α-S8, by moderate thermoacidophile Sulfobacillus thermosulfidooxidans

“…They found pure a-S 8 or pure m-S was oxidized faster than mixed sulfur allotropes, but no difference in the utilization between pure a-S 8 and pure m-S. Franz et al [15] reported that phototrophic sulfur bacterium Allochromatium vinosum only uses the chain-like m-S. However, Blight et al [12] observed the preferential oxidation of a-S 8 by a heterogeneous culture. He et al [13] found that cyclo-octasulfur is firstly converted to polymeric sulfur before oxidized by mesoacidophilic Acidithiobacillus ferrooxidans.…”

“…Fourier transform-infrared spectroscopy (FT-IR) demonstrates the biochemical modification of solid substrates by SOM [18]. X-ray diffraction (XRD) and Raman spectroscopy are useful methods to characterize different sulfur allotropes [12]. Sulfur K-edge X-ray absorption near edge structure (XANES) spectroscopy, with high resolution and sensitivity, is the first choice to investigate the speciation of an elemental of interest in most cases [22].…”