Ribonucleosides can be produced by calcium-catalyzed cleavage of RNA f
ollowed by dephosphorylation of calcium salts of mononucleotides by in
tact mycelium of Spicaria violacea as a biocatalyst. Under optimal con
ditions the efficiency of degradation of baker's yeast RNA to a mixtur
e of ribonucleosides is 96% of the theoretical value.