[Influence of carbon sources on the biological activity and morphology of Bacillus thuringiensis parasporal crystals].

The influence of the carbon source on biological activity and morphological properties of the parasporal crystals of Bacillus thuringiensis subsp. kurstaki cultivated on three different media has been studied. Biological activity of delta-endotoxins contained in crystals was tested according to their impact on insects and microorganisms.

[The study of the growth of tylosin producer using differential centrifugation of mycelium in a sucrose density gradient].

The mycelium of Streptomyces fradiae was fractionated by differential centrifugation in a sucrose density gradient (SDG) using various samples of the inoculation material and aliquots of the cultural broth taken in the course of tylosin production. The mode of mycelium distribution in SDG made it possible to select the most active inoculation material. The mycelium was redistributed from sucrose layers with a high density to those with a lower density in the course of fermentation.

[The function of Salmonella typhi at different stages in the pathogenesis of typhoid infection].

The complex study of the adhesive, colicinogenic and antigenic properties of S. typhi of different origin has revealed that adhesive properties can be observed more frequently in the strains isolated from the blood and bile and are completely absent in the strains isolated from feces. S.

[Membrane potential levels in Acetabularia cells].

The membrane potential (MP) of A. mediterranea cell is shown to have two stationary levels RP==--170 mv and EP=--80 mV and an unstable one -- level of action potential peaks -- EP=--60 mV. The following transitions between the MP levels are possible: RP leads to EP' equilibrium EP leads to RP.

[Electric parameters and equivalent schematics for Acetabularia cells].

Was measured values of electric resistance (R) and capacity (C) of A. mediterranea cell at different levels of the membrane potential (MP). At the level -170 mV, RRP=4,3 KOm-cm2, at the level -80 mV REP=1,4 KOm-cm2.