RT Journal Article SR Electronic(1) A1 Luque-Almagro, Victor M. A1 Merchán, Faustino A1 Blasco, Rafael A1 Igeño, M. Isabel A1 Martínez-Luque, Manuel A1 Moreno-Vivián, Conrado A1 Castillo, Francisco A1 Roldán, M. DoloresYR 2011 T1 Cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 involves a malate : quinone oxidoreductase and an associated cyanide-insensitive electron transfer chain JF Microbiology, VO 157 IS 3 SP 739 OP 746 DO https://doi.org/10.1099/mic.0.045286-0 PB Microbiology Society, SN 1465-2080, AB The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to grow with cyanide as the sole nitrogen source. Membrane fractions from cells grown under cyanotrophic conditions catalysed the production of oxaloacetate from l-malate. Several enzymic activities of the tricarboxylic acid and glyoxylate cycles in association with the cyanide-insensitive respiratory pathway seem to be responsible for the oxaloacetate formation in vivo. Thus, in cyanide-grown cells, citrate synthase and isocitrate lyase activities were significantly higher than those observed with other nitrogen sources. Malate dehydrogenase activity was undetectable, but a malate : quinone oxidoreductase activity coupled to the cyanide-insensitive alternative oxidase was found in membrane fractions from cyanide-grown cells. Therefore, oxaloacetate production was linked to the cyanide-insensitive respiration in P. pseudoalcaligenes CECT5344. Cyanide and oxaloacetate reacted chemically inside the cells to produce a cyanohydrin (2-hydroxynitrile), which was further converted to ammonium. In addition to cyanide, strain CECT5344 was able to grow with several cyano derivatives, such as 2- and 3-hydroxynitriles. The specific system required for uptake and metabolization of cyanohydrins was induced by cyanide and by 2-hydroxynitriles, such as the cyanohydrins of oxaloacetate and 2-oxoglutarate., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.045286-0