Arginine catabolism in Aphanocapsa 6308

Abstract

The catabolic products of arginine metabolism were observed in Aphanocapsa 6308, a unicellular cyanobacterium, by thin layer chromatography of growth media, by limiting growth conditions, and by enzymatic analysis. Of the organic, nitrogenous compounds examined, only arginine supported growth in CO2-free media. The excretion of ornithine at a concentration level greater than citrulline suggested the existence in Aphanocapsa 6308 of the arginine dihydrolase pathway which produced ornithine, CO2,NH4,+ adenosine 5'-triphosphate. Its existence was confirmed by enzymatic analysis. Although cells could not grow on urea as a sole carbon source a very active urease and subsequently an arginase were also demonstrated, indicating that Aphanocapsa can metabolize arginine via the arginase pathway. The level of enzymes for both pathways indicates a lack of genetic control. It is suggested that the arginase pathway provides only nitrogen for the cells wheras the arginine dihydrolase pathway provides not only nitrogen, but also CO2 and adenosine 5'-triphosphate.

Arginine Catabolism in the Cyanobacterium Synechocystis sp. Strain PCC 6803 Involves the Urea Cycle and Arginase Pathway

“…(4,22,31,44,48). Arginine deiminase activity has also been reported for some strains of Anabaena sp., Aphanocapsa (Synechocystis) sp., and Nostoc sp.…”

“…Arginine deiminase activity has also been reported for some strains of Anabaena sp., Aphanocapsa (Synechocystis) sp., and Nostoc sp. (22,31,48). On the other hand, Synechococcus sp.…”

Formation and functional significance of storage products in cyanobacteria

“…However, Weathers et al (1978) demonstrated that cyanophycin could not be used as a carbon source by Aphanocapsa 6308.…”

Amino acid transport in taxonomically diverse cyanobacteria and identification of two genes encoding elements of a neutral amino acid permease putatively involved in recapture of leaked hydrophobic amino acids

“…Amino acids like Arg, Asn, and Gln can be used as sources of nitrogen by a number of cyanobacteria (7), while Arg has been described to serve as a source of carbon for Synechocystis (Aphanocapsa) sp. strain PCC 6308 (29).…”