Properties of Ribosomes from Streptomyces erythreus and Streptomyces griseus

Ribosomes from an erythromycin-producing strain, Streptomyces erythreus, lacked affinity for erythromycin and were also resistant to other macrolide antibiotics (leucomycin, spiramycin, and tylosin) and to lincomycin, whereas Streptomyces griseus B(3) ribosomes were susceptible to all of these antibiotics.     

Iron release analyses from ferritin by visible light irradiation

We investigated the iron release from ferritin by irradiation from a white fluorescent light in the absence or presence of ADP. Irradiation of a ferritin solution at 17,000 lx in the absence of ADP slightly induces iron release from ferritin but only at acidic pH conditions (pH 5.0 or pH 6.0). Irradiation in the presence of ADP markedly enhances iron release from ferritin under the same conditions. In the absence of irradiation, the iron release from ferritin was low even in the presence of ADP. The induction of the iron release by irradiation in the presence of ADP was also affected by various factors such as irradiation dose and acidity, but not temperature (4-47°C), oxygen concentration, or free radical generations during the irradiation. The iron release during the irradiation ceased to increase by turning off the light and was found to increase again after additional irradiation. These results suggest that visible light directly induces iron release from ferritin via the photoreduction of iron stored inside ferritin.     

Effect of the A-factor on the adenylate level in Streptomyces griseus

The adenylate content of various strains of Streptomyces griseus was measured. With respect to the ATP and ADP content the strains capable of spore formation, streptomycin synthesis and A-factor (2-isocapryloyl-3-hydroxymethyl-4-hydroxybutyrolactone) synthesis differed from the A-factor deficient mutants. The addition of the A-factor to the recipient strains decreased the intracellular content of ATP and the ATP/ADP ratio. The strain which is not an A-factor recipient did not modify the ATP content when the A-factor was added to the medium.     

Effect of aminoglycoside antibiotics on the autolytic enzyme of Streptomyces griseus

The isolated cell wall of Streptomyces griseus 52–1 strain labelled with fluorescein isothiocyanate (FITC) and containing wall-bound autolytic enzyme was lysed as a function of different cations. The autolysis was accelerated by aminoglycoside antibiotics (streptomycin and the structurally closely related neomycin) which have a polycationic character. Since this strain is a streptomycin producer it is suggested that streptomycin may have a regulatory function on autolysis.     

Effect of nonmutagenic doses of 1,4-bis-diazoacetylbutane on Streptomyces griseus

Streptomyces griseus 15 was subjected to the action of 1,4-bis-diazoacetyl butane (DAB) taken at concentrations of 10 to 50,000 micrograms/ml. Small doses (10-100 micrograms/ml) of DAB had no mutagenic action and activated the cultural growth (the viability and the survival rate of spores increased on solid media, while the biomass yield rised in liquid media). Experiments were conducted using the method of orthogonal planning of a bifactorial experiment, and the role of the exposure time rised with a decrease in the mutagen concentration.     

Biosynthesis of N-methyl-l-glucosamine from d-glucose by Streptomyces griseus

Biosynthesis of $\text{N-}\text{methyl}\text{-}\text{l}\text{-}\text{glucosamine}$ moiety of streptomycin from d-glucose by Streptomyces griseus was studied. A mixture of d-[1-¹⁴C]glucose and d-[6-³H]glucose was given to the culture of S. griseus. The ³H/¹⁴C ratio found in $\text{N-}\text{methyl}\text{-}\text{d}\text{-}\text{glucosamine}$ further supports a mechanism that the conversion of d-glucose to l-hexose is carried out without scission of carbon skeleton. When d-[1-¹⁴C]glucose and d-[3-³H]glucose were used, the fall of ³H/¹⁴C ratio in $\text{N-}\text{methyl}\text{-}\text{l}\text{-}\text{glucosamine}$ showed that the hydrogen atom at C-3 plays a rôle in such a transformation.