[Selection of the medium for the simultaneous synthesis of an antibiotic, protease and pigment by a Nocardia fructiferi culture]. / Podbor sredy dlia odnovremennogo sinteza kul'turoi Nocardia fructiferi antibiotika, proteaz i pigmenta.

Using method of mathematical planning of experiment the culture medium ensuring the simultaneous intensive production of ristomycin, protease and violet pigment by Nocardia fructiferi has been worked out.

[Several conditions of formation and isolation of violet pigment from culture fluid of Nocardia fructiferi var. ristomycin]. / Izuchenie nekotorykh uslovii obrazovaniia i vydelenie iz kul'tural'noi zhidkosti Nocardia fructiferi var. ristomycini fioletovogo pigmenta.

A new water-soluble photochromogenic fluorescent violet pigment with the indicator properties was isolated from the culture fluid of Nocardia fructiferi var. ristomycini, strain 76. By its solubility and mobility in various solvent systems and by the absorption spectrum the new pigment is close but not identical to such a pigment as rubrocyanin. The presence of microelements, i.e. iron and magnesium in the medium was shown to be necessary for production of violet pigment.

[Properties of the extracellular proteases of Nocardia fructiferi var. ristomycini]. / Izuchenie nekotorykh svoistv vnekletochnykh proteaz Nocardia fructiferi var. ristomycini.

A complex of proteases was isolated from the culture fluid of Nocardia fructiferi var. ristomycini, strain 76. The complex showed caseinolytic activity and was capable of coagulating milk for 30 minutes. It was stable at a temperature of 50 degrees C and pH 8.0. The maximum level of casein hydrolysis was observed at 37 degrees C and pH 8.0. The protease complex preserved its properties for 3 months at 4 degrees C and for 1 month at room temperature.

[Effect of various carbon and nitrogen sources on the biosynthesis of ristomycin, protease and pigments by a culture of Nocardia fructiferi var. ristomycini]. / Vliianie razlichnykh istochnikov ugleroda i azota na biosintez ristomitsina, proteazy i pigmentov kul'turoi Nocardia fructiferi var. ristomycini.

The effect of various sources of carbon and nitrogen on the biosynthesis of ristomycin, protease and pigments by Nocardia fructiferi was studied. It was shown that the carbon sources had the most significant effect on the biosynthesis of the antibiotic. The maximum biosynthetic activity of the Nocardia was observed in the medium containing 1-2 per cent of soybean meal and 2 per cent of glycerol. Under such conditions all the three biologically active substances formed. The contents of ristomycin, protease and pigments amounted to 562-649 microgram/ml, 26-30 PU/ml and 0.45-0.63 conditional units, respectively.

[Action of novobiocin on the capacity of Nocardia fructiferi var. ristomycini for ristomycin biosynthesis]. / Deistvie novobiotsina na sposobnost' Nocardia fructiferi var. ristomycini k biosintezu ristomitsina.

The effect of novobiocin in concentrations of 0.05 and 0.2--0.3 microgram/ml on morphological variation of N. fructifer and its capacity for ristomycin production was studied. It was found that the number of colonies with the maximum activity increased under the effect of novobiocin used in a concentration of 0.05 microgram/ml. An increase in the level of novobiocin in the medium up to 0.2--0.3. microgram/ml markedly increased the number of the colonies with low antibiotic productivity.