The position of actinomycetes in taxonomical systematization was not definite in its early studies. Actinomycetes resembles bacteria in some respects and fungi on the other hand. Harz (1877),1) Gedoelst (1902)2) and Petruschky (1903)3) had put actinomycetes in fungi. Lehman and Neuman (1896)4) settled it in supplementary group of bacteria. Since the middle of 20th century, it was placed in bacteria “Schizomycetes”. Waksman (1950)5) stated that the actinomycetes may tentatively be placed in taxonomical transition group between Schizomycetes and Hyphomycetes. But recent evidences seemed to point the fact that actinomycetes are not to be considered as higher fungi and they appeared to be more closely related to the bacteria. One of those evidences is that actinomycetes are usually sensitive to antibacterial antibiotics as well as bacteria but not to antifungal antibiotics. Waksman et al. (1953)6) reported decreasing sensitivity to isoniazide in order of pathogenic Mycobacteria→saprophytic Mycobacteria→Micromonospora→Nocardia→Streptomyces.
In this paper, the authors made a survey of selective sensitivity of actinomycetes (especially streptomycetes) and related organisms to various antibiotics.
It is very interesting to know the distribution of Streptomyces in natural environment. Several investigators, such as Waksman and Curtis (1916)1), Conn (1917)2), Jensen (1930)3) and Johnston (1947)4) have reported on the distribution of Streptomyces in the soil. However, very little is known about the distribution of Streptomyces classified on the basis of morphological types. Recently, we have collected soil samples from 3 areas near Osaka and isolated totally 848 strains of Streptomyces: 277 strains from 23 soil samples collected from Shioya, Kobe city, 431 strains from 24 soil samples collected from Minō Park, Osaka Prefecture, and 140 strains from 18 soil samples collected from Abuyama, Osaka Prefecture.
The purpose of this report is to present the result of classification of the isolates based on our classification system (1959)5), 6).
In the preceding communications1),2),3) of this series, it was reported that L-glutamate was oxidized by the streptomycin-producing microorgnism, Streptomyces griseus K-I. The L-glutamate oxidation by the intact mycelium of S. griseus was reported in the previous paper3).
The extraction of the soluble L-glutamic dehydrogenase from the freeze-dried powder2) and the wet mycelium3) of S. griseus was unsuccessful. It was believed that all procedures were rendered difficult, because S. griseus contained the excess amount of the slime substance. Sohler et al4) demonstrated that S. griseus, S. fradiae, and Micromonospora among the genus Streptomyces were lyzed by lysozyme. There are many instances of the lysis of cell walls or the enzyme extraction by lysozyme, but the glutamic dehydrogenase is completely inactivated by this enzyme5).
The author succeeded in obtaining the soluble L-glutamic dehydrogenase from the mycelium paste with aid of the fresh egg white under suitable conditions. In the present study, some results on L-glutamate oxidation by using this crude enzyme solution will be reported. In addition various phenomena of the L-glutamate oxidation by the intact mycelium and the crude enzyme solution of S. griseus will be discussed.
In a previous paper of this series,1) the authors have reported that the adaptive oxidation of benzoic acid, niacin and malonic acid by avian tubercle bacilli were remarkably inhibited by a small amount of kanamycin (KM) and also the successive adaptation of benzoic acid was completely inhibited. Adaptive oxidation of these substrates by streptomycin-resistant strain was never inhibited even by a large amount of streptomycin (SM), while completely inhibited with a small amount of KM, and on the contrary, oxidation by KM-resistant strain was inhibited by SM, but KM had no effect on the reactions.
In this paper, the inhibitory effect of KM on the oxidation of C4-dicarboxylic acids (malate, fumarate, succinate) and diamine (putrescine) by avian tubercle bacilli is described.
A couple of nucleoside antibiotics, angustmycins A and C, were obtained from the broth filtrate of Streptomyces hygroscopicus var. angustmyceticus and characterized.1),2) Their chemical structures were determined by Yüntsen. Angustmycin A is 6-amino-9-(L-1,2-fucopyranoseenyl)-purine and angustmycin C 6-amino-9-(β-D-psicofuranosyl)-purine.3),4) The former antibiotic was first reported to exhibit antimicrobial activity exclusively against mycobacteria and the latter little activity.2)
These antibiotics showed a certain activity against transplantable animal tumors. Recently an antibiotic identical with angustmycin C was isolated and named psicofuranine by the workers of the Upjohn Company, Kalamazoo, Michigan.5–8)
Although both antibiotics were observed to exert antibacterial effects against grampositive organisms including mycobacteria in synthetic media, their activities decreased in organic media. It indicates that there exist certain antagonists, which are contained in the organic media. In this paper in vitro antimicrobial activity of angustmycins and effects of various vitamins and nucleic acid constituents on the activity of angustmycins are described, with reference to their mode of action.
An antibiotic active specifically against Mycobacterium tuberculosis BCG has been isolated in crystalline form the culture filtrates of a streptomycete* isolated from a soil sample. The antibiotic has a formula of C10H12N4O4 and a characteristic absorption at 263 mμ. Acid hydrolysis study followed by the paperchromatography proved the presence of purine and D-ribose. The subsequent comparative studies with the synthetic specimen proved that the antibiotic is 9-β-D-ribofuranosylpurine.
This nucleoside is a synthetic anticancer agent1) and its occurrence in nature was first found in the mushroom, Agaricus neburaris, in minute quantity and named as nebuline.2) This is the second case found as the natural product and is the first time that this nucleoside is isolated as a metabolic product of streptomycete.
Although many antibiotics against bacteria were so far isolated as products of streptomyces, substances effective against small viruses, such as small pox, influenza, poliomyelitis and Japanese encephalitis viruses in vivo, were only infrequently reported. No agent, whether chemicals or antibiotics, could ever protect the animals from infections of small viruses.
Among substances described to possess an antiviral activity,1),2),5),8),11),16)–43) only achromoviromycin,1) an antibiotic, and PANS,2) a chemical, were described to have an activity against Japanese B. encephalitis (JBE). The latter found a clinical application, though its effect is not decisive.
In our laboratory, soil isolates of streptomyces were tested for their activity against JBE virus in mice, and culture filtrate of streptomyces was proved to protect the mice against the infection with JBE virus. From the filtrate, a new effective substance was isolated and was given the name of cephalomycin.3) This paper deals with the experiment in mice infected with JBE virus, and the experiments for protection against reinfection with JBE in the surviving mice.