Studies on microbial RNases began in 1924 when NOGUCHI found nucleic
acid degrading enzymes in Takadiastase, a commercially prepared digest
from Aspergillus oryzae. In 1935 OrANI reported the presence of enzymes
degrading yeast RNA in fungi (Aspergillus sp. etc.). In 1948, MCCARTY
studied the nuclease activity in 36 strains of group A hemolytic
Streptococci and indicated the release of both RNase and DNase from
Streptococcal cells during growth in culture media. As is well known,
these nucleases (TILLETT et al., 1948) are applied in the treatment of
inflammatory exudates. In 1952, MUGGLETON and WEBB found RNase in the
culture medium of Actinomy- ces (strain A), and they suggested that the
ability of the medium to render killed Gram-positive cells Gram-negative
may be due to the RNase. In the same year PARDEE and his colleagues
(1952 a, b) found RNase activity in E. coli (strain B) in- fected by
bacteriophage T r, T3 etc. 2 KUNINAKA (1954) found ribonuclease in
culture @trates of Aspergillus oryzae.