[Antibacterial spectrum of lisosubtilin G10X]. / Antibakteria'lnyi spektr lizosubtilina G10X.

Data on the antibacterial spectrum of lysosubtilin G10X, a preparation of lytic enzymes from Bacillus subtilis SK-52 are presented. Lysosubtilin was active against grampositive and gramnegative pathogenic bacteria. When it was used as a substrate of live lyophilized microbial cells the highest lysis levels were observed in B. brevis, B. cereus, B. pumilis, B. subtilis and S. faecalis. Preincubation of the substrate in acid media mainly increased the levels of the lysis by enzyme preparation. Sometimes the increase was very high (B. sphaericus, B. subtilis 720, E. coli K12 and MRE-600). Such a preincubation provided cell lysis in some strains not liable to the effect of lysosubtilin (B. cereus 1312, C. renale, M. luteus, S. aureus KP, 800, 805 and 126001, S. pyogenes 291). An increase in the lysosubtilin concentration in the reaction mixture in the majority of the cases did not provide favourable results. However, some strains resistant to the preparation at a concentration of 1000 units/ml were lysed with its 10 times higher doses. An increase in the lysis level was also achieved with increasing the time of the incubation with the enzyme preparation. Proceeding from the preparation antibacterial spectrum it is possible to recommend it for treatment of diseases in agricultural animals. Its use in veterinary was a success.

[Lysosubtilin G10x--a new antimicrobial agent for treatment and prophylaxis. Physico-chemical properties]. / Lizosubtilin G10x--novyi antimikrobnyi agent lechebno-profilakticheskogo naznacheniia. Fiziko-khimicheskie svoistva.

Lysosubtilin G10x, a lytic enzyme from Bacillus subtilis SK-52 was studied with respect to its physico-chemical properties such as effect of optimal conditions and stability. The maximum activity of the enzyme was observed in phosphate buffer at a concentration of the buffer mixture equal to 0.004 M, pH 7.2 and the temperature of 37-50 degrees C. Aqueous solutions of lysosubtilin G10x were stable at pH 5-9. The lytic activity of the enzyme aqueous solutions rapidly lowered at a temperature above 50 degrees C. The ions of some metals, especially those of mercury, copper and ferrous iron inhibited the enzyme. Lysis activation was recorded in the presence of surface active substances such as sodium dodecylsuphate, tritone X-100 and certain twins. Comparison of the findings with the results of our previous studies on the lytic properties of enzymes from other strains of B. subtilis showed that irrespective of the strain lysosubtilins were sensitive to changes in the medium ionic strength, they were mostly active in neutral solutions of low ionic strength, their activity was inhibited by heavy metal ions and they were stable within wide ranges of pH. This should be taken into account in practical use of lysosubtilin G10x.