[Effect of aeration and agitation conditions on gentamycin biosynthesis].

The study on the relation between the production of gentamicin and the conditions of aeration and agitation of the fermentation broth showed the advisability of the control of these parameters with respect to the maximum rate of the oxygen uptake. Possible scaling-up of the process of gentamicin biosynthesis was shown with the use of the expression: (formula: see text).

[Oxidative-reductive activity of the mycelium as a criterion for assessing inoculate quality in gentamycin biosynthesis].

The development of the seed mycelium at various stages and temperatures was studied with the method of methylene blue decolorization characterizing the respiration level of the culture and its oxidation-reduction (dehydrogenase) activity. Relationship between the time of methylene blue decolorization by the seed mycelium, the quantity of the inoculum transferred from one stage to the other and the temperature of cultivation was shown. The seed mycelium decolorizing methylene blue within 2 minutes was most productive at the biosynthetic stage irrespective of the growth period, biomass volume, cultivation temperature and volume of the inoculum transferred from one stage to the other.

[Significance of pH for the growth of the sisomicin producer and biosynthesis of the antibiotic].

Dependence of the mycelium growth and sisomycin production on the pH values of the fermentation broth was studied in cultures of various ages for 6 hours with the method of pH control within the preset levels. It was shown that the values of pH within the range of 7.25 - 7.

[Development of a gentamicin producer under different culture conditions studied by a method of differential centrifugation of the mycelium in a saccharose density gradient].

The method of differential centrifugation in the sucrose density gradient (SDG) enabled one to trace the changes in the development of the seed and fermentation mycelium of the gentamicin-producing organism. Correlation between gentamicin distribution in the SDG and the culture productivity was found. It was shown that the culture grown under the optimal aeration and agitation conditions was characterized by formation of higher amounts of the mycelium in the 5th and 6th layers of the SDG.