Alkaliphilus metalliredigens QYMF

Alkaliphilus metalliredigens (strain QYMF) is s an alkaliphilic, moderately halophilic metal-reducing bacterium phylogenetically associated with the Firmicutes. A. metalliredigens was isolated from borax leachate ponds. Alkaliphilus metalliredigens can reduce Fe(III)-citrate, Fe(III)-EDTA, Co(III)-EDTA, or Cr(VI) as electron acceptors with yeast extract or lactate as electron donors. Growth during iron reduction occurs over the pH range of 7.5 to 11.0, a sodium chloride range of 0 to 80 g/l and a temperature range of 4 degrees Celsius to 45 degrees Celsius. Optimal growth conditions during iron reduction in the presence of borate (2 g/l) were observed at a pH of 9.6, a sodium chloride concentration of 20 g/l and a temperature of approximately 35 degrees Celsius. A. metalliredigens is a strict anaerobe that can tolerate up to 1.5% (w/v) borax (Na2B4O7), and the cells are straight rods that produce endospores. The microorganism appears to be a novel metal-reducing bacterium that is distantly related to other commonly studied iron-reducing microorganisms. At the present time (December 2007), the most closely related microorganisms are Alkaliphilus transvaalensis and Alkaliphilus crotonatoxidans. (EBI Integr8)