Microbially promoted calcite precipitation in the pelagic redoxcline: Elucidating the formation of the turbid layer.

Large bell-shaped calcite formations called "Hells Bells" were discovered underwater in the stratified cenote El Zapote on the Yucatán Peninsula, Mexico. Together with these extraordinary speleothems, divers found a white, cloudy turbid layer into which some Hells Bells partially extend. Here, we address the central question if the formation of the turbid layer could be based on microbial activity, more specifically, on microbially induced calcite precipitation.

Persulfide Dioxygenase From : Variable Roles of Cysteine Residues and Hydrogen Bond Networks of the Active Site.

Persulfide dioxygenases (PDOs) are abundant in Bacteria and also crucial for HS detoxification in mitochondria. One of the two -genes of the acidophilic bacterium was expressed in The protein (PDO) had 0.77 ± 0.

The Sulfur Oxygenase Reductase Activity Assay: Catalyzing a Reaction with Elemental Sulfur as Substrate at High Temperatures.

The sulfur oxygenase reductase (SOR) reaction is a dioxygen-dependent disproportionation of elemental sulfur (S), catalyzed at optimal temperatures between 65 °C and 85 °C. Thiosulfate and sulfite are formed as oxidized products as well hydrogen sulfide as reduced product. External co-factors are not required.

A Sulfur Oxygenase from the Haloalkaliphilic Bacterium Thioalkalivibrio paradoxus with Atypically Low Reductase Activity.

Unlabelled: Sequence comparisons showed that the sulfur oxygenase reductase (SOR) of the haloalkaliphilic bacterium Thioalkalivibrio paradoxus Arh 1 (TpSOR) is branching deeply within dendrograms of these proteins (29 to 34% identity). A synthetic gene encoding TpSOR expressed in Escherichia coli resulted in a protein 14.7 ± 0.

Cytochromes c in Archaea: distribution, maturation, cell architecture, and the special case of Ignicoccus hospitalis.

Cytochromes c (Cytc) are widespread electron transfer proteins and important enzymes in the global nitrogen and sulfur cycles. The distribution of Cytc in more than 300 archaeal proteomes deduced from sequence was analyzed with computational methods including pattern and similarity searches, secondary and tertiary structure prediction. Two hundred and fifty-eight predicted Cytc (with single, double, or multiple heme c attachment sites) were found in some but not all species of the Desulfurococcales, Thermoproteales, Archaeoglobales, Methanosarcinales, Halobacteriales, and in two single-cell genome sequences of the Thermoplasmatales, all of them Cren- or Euryarchaeota.