Compensation phenomena found in Acidithiobacillus ferrooxidans after starvation stress

Abstract

Acidithiobacillus ferrooxidans showed the compensate growth and oxidation after re-feeding with sufficient ferrous materials after starvation. Compensatory phenomena were first detected in chemoautotrophic organisms. Starvation stress of Acidithiobacillus ferrooxidans was achieved via culturing in low concentrations of iron. During compensation, growth and ferrous oxidation took place faster than in controls. In addition, some genes related to ferrous oxidation (such as rus) and carbon assimilation (cbbR, csoS3) were expressed in different patterns in the low energy environments. Their expression patterns can account for this increased growth and oxidation. Other groups of genes (cspAB, feoAB, fur) were suppressed in response to starvation stress. The presence of pyrite and joint cold stress can render compensation nearly undetectable. This may be why the compensation phenomena observed under these conditions was not the same as that observed under single starvation stress conditions. Gene expression reflected a possible mechanism of tolerance to starvation in Acidithiobacillus ferrooxidans, which would allow the organism to adapt and survive in ferrous-limited environments.

Chemical and surface analysis during evolution of arsenopyrite oxidation by Acidithiobacillus thiooxidans in the presence and absence of supplementary arsenic

“…total proteins analysis, see below). Acidithiobacillus strains respond differently according to specific SM surface properties and physicochemical conditions (Devasia and Natarajan, 2010;Ngoma et al, 2015), since the absence of available ferrous concentrations in system allows starvation effects by A. ferrooxidans cells (Sharma et al, 2003;Tu et al, 2014), and because A. thiooxidans cells are able to perform sustained chalcopyrite biooxidation, in spite of cells partially covered by secondary covellite (CuS)-like compounds (Falco et al, 2003;Lara et al, 2013). Accordingly, biofilm and arsenopyrite interactions can be significantly modified in the presence and absence of supplementary arsenic in the system.…”

“…4c ″), indicating that EPS acts as a protecting barrier against toxic metallic species such as As(V), and it is a bacterial survival strategy for nonleaching bacteria (Harrison et al, 2005;Vu et al, 2009). Note that bacterial EPS over-production is typically low for leaching SOM and IOM strains (Tu et al, 2014;Lara et al, 2013), in comparison with nonleaching bacteria (i.e. Bacillus subtilis, Pseudomona aeruginosa) (Breed et al, 1996;Leng et al, 2009).…”

Sulfur Transformation in Microbially Mediated Pyrite Oxidation by Acidithiobacillus ferrooxidans: Insights From X-ray Photoelectron Spectroscopy-Based Quantitative Depth Profiling

“…4F). Owing to the surface attachment, the cell number in solution temporarily decreased between the 4 th and 7 th day (Tu et al 2014), which could promote the growth of bacteria (Fig. 1) and ultimately transformed to Fe 3+ (Fig.…”

Role of manganese in protection against oxidative stress under iron starvation in cyanobacterium Anabaena 7120

“…Iron act as an important cofactor for variety of crucial enzymes regulating several important metabolic pathways, such as nitrogen fixation, assimilation of nitrogen, photosynthesis etc . Several microorganisms like Thiobacillus, Acidithiobacillus, Leptospirillum and Ferroplasma also use iron (Fe 2+ ) as the source of electron to meet their energy demand . Iron deficiency is related to several unavoidable consequences, hence can be considered as stress .…”