Synthesis and properties of ammoniojarosites prepared with iron-oxidizing acidophilic microorganisms at 22–65 °C

Simultaneous oxidation and precipitation of iron using jarosite immobilized Acidithiobacillus ferrooxidans and its relevance to acid mine drainage

“…This result is consistent with Dutrizac (1983), who reported that K + is preferentially precipitated as jarosite with respect to NH 4 + , and the partitioning is not strongly dependent on the total alkali concentration. The molar ratio of (K,NH 4 ):Fe:SO 4 of the synthetic jarosite, as shown in Wang et al (2007), such ionic composition and concentration would result in the precipitation of a mixture of jarosite and schwertmannite. In fact, schwertmannite was always formed when jarosite-directing cations (e.g., K, NH 4 , Na) were limiting (Gramp et al, 2008;Wang et al, 2007).…”

Nanoscale study of As biomineralization in an acid mine drainage system

“…Several studies have characterized the diversity of microorganisms and of specific metabolic genes in AMD systems (e.g., Lopez-Archilla et al, 2004;Bruneel et al, 2006;Baker et al, 2006;Lo et al, 2007), and the spatial and temporal compositional and mineralogical variations using bulk analyses Casiot et al, 2003Casiot et al, , 2005. Other studies have developed models to identify the different abiotic and biotic actors involved in the evolution of As speciation (e.g., Lazaroff et al, 1982;Bruneel et al, 2003;Duquesne et al, 2003;Wang et al, 2007). However, only a few studies have provided chemical, mineralogical and biological data at the submicrometer spatial scale (e.g., Clarke et al, 1997;Ohnuki et al, 2004).…”

Gene expression modulation by heat stress in Acidithiobacillus ferrooxidans LR

“…The expression of cbbS-2, which encodes the small subunit of the ribulose-1,5-biphosphate carboxylase/oxygenase enzyme (Rubisco), increased significantly (22-fold) after 60 min of heat shock (Table 1). In addition to having a direct influence on biological processes, temperature may indirectly affect gene expression by interfering with physicochemical parameters such as gas solubility (Stintzi 2003) or ferrous stability (Wang et al 2007). According to Wei et al (2004), the transcript levels of the Rubisco operon genes increase under low CO 2 and decrease under higher CO 2 .…”