It is well known that adenine derivatives are deaminated by adenase, adenosine deaminase and adenylic acid deaminase. However, only guanase has been known for guanine derivatives as the deaminating enzymes. Degradation of guanosine by bacterial enzymes has been known to proceed by a combination of nucleoside phosphorylase or nucleosidase and guanase yielding xanthine.
The authors isolated about 400 bacteria from soil and found that a strain No. 149 seemed to produce a new enzyme, guanosine deaminase which directly deaminates guanosine producing xanthosine.
Furthermore, the morphological, cultural and physiological properties of this strain were investigated. From these results, the bacterium was classified as Pseudomonas convexa CHESTER.
