The immobilization of Acidithiobacillus ferrooxidans cells on ceramic beads as carrier is described. The effects of ferrous ion concentration and dilution on the kinetics of ferrous ion oxidation in a packed-bed bioreactor were studied. In a medium containing 13.91 g of ferrous ion per litre, the fastest oxidation rate was 4.21 g L–1 at a dilution rate of 0.8 h–1. The corresponding conversion w...

At an initial pH of 2, while abiotic oxidation of aqueous Fe(2+) was enhanced by a flux of H2O2 at micromolar concentrations, bio-oxidation of aqueous Fe(2+) could be impeded due to oxidative stress/damage in Acidithiobacillus ferrooxidans caused by Fenton reaction-derived hydroxyl radical, particularly when the molar ratio of Fe(2+) to H2O2 was low. When pyrite cubes were intermittently expose...

The attachment of microorganisms to electrodes is of great interest for electricity generation in microbial fuel cells (MFC) or other applications in bioelectrochemical systems (BES). In this work, a microcosm of the acidic ecosystem of Río Tinto was built and graphite electrodes were introduced at different points. This allowed the study of electricity generation in the sediment/water interfac...

The kinetics of sulfur oxidation by Acidithiobacillus ferrooxidans in shaking flasks and a 10-L reactor was studied. The observed linearity of growth and sulfur oxidation was explained by sulfur limitation. Total cell yield was not significantly different for exponential growth as compared to growth during the sulfur-limiting phase. Kinetic studies of sulfur oxidation by growing and nongrowing ...

The regulation of the expression of the rus operon, proposed to encode an electron transfer chain from the outer to the inner membrane in the obligate acidophilic chemolithoautroph Acidithiobacillus ferrooxidans, has been studied at the RNA and protein levels. As observed by Northern hybridization, real-time PCR and reverse transcription analyses, this operon was more highly expressed in ferrou...

Sewage sludge management for fertilizer purposes can be a step in the circular phosphorus (P) economy. Using microbial solubilization manufacturing fertilizers from recycled materials is an innovative approach with potential to increase P compounds’ bioavailability, and sewage ash P-solubilizing bacteria are promising products of this technology. In addition range macronutrients, these contain ...