The enzymatic cleavage of canavanine to homoserine and hydroxyguanidine.

Previous studies have shown canavanine to be a potent antagonist of arginine in Neurospora (1) and in some bacteria, but not in others (2, 3). Streptococcus faecaks belongs to the resistant group of bacteria and has been shown to degrade canavanine in two distinct ways: by reductive cleavage to guanidine and homoserine (4) and, to a lesser extent, by hydrolytic cleavage to ammonia and 0-ureidohomoserine (5). In an extension of these studies, a pseudomonad capable of utilizing canavanine as a sole source of carbon and nitrogen was isolated from soil by the enrichment culture technique. The initial attack on canavanine by this organism was found to consist in a hitherto undescribed cleavage of this amino acid to yield hydroxyguanidine and homoserine. The present paper deals with the demonstration of this reaction.