[The mechanisms of the manifestation of the genotoxic effects of binase].

The high concentrations of commercial sample of Bacillus intermedius 7P ribonuclease (binase) showed a weak mutagenic effect in Ames test and Ara-test. It has been established that binase induces the SOS-functions of microbial cell and prophage induction. The way of exogenic enzyme action through activation of RecA protein is proposed.

[An evaluation of the genotoxicity of nonionogenic surface-active substances].

The mutagenic activity of 16 industrial nonionic surfactant samples has been investigated in Ames-test without metabolic activation and with the use of mouse liver microsomal fraction in vitro. The genotoxical estimation of their possible biodegradation products is given. The mutagenicity of a number of high molecular polyethylene glycoles related to nonionic surfactants is shown.

[Assessment of the genotoxicity of the "Binase" enzyme preparation].

"Binase" enzyme sample (a microbial ribonuclease) has been tested for mutagenicity in a set of tests. The set included Ames test Salmonella/microsome, Escherichia coli Rec-test, bacteriophage induction assay, DNA-repair synthesis in lymphoid cells. "Binase" is shown to possess a small genotoxic effect at high concentrations.

[Transformation of 2,4,6-trinitrotoluene during oxygen and nitrate respiration in Pseudomonas fluorescens].

A study of the metabolic pathway and the rate of 2,4,6-trinitrotoluene (TNT) transformation depending on the nature of the electron acceptor in the electron transport chain of Pseudomonas fluorescens B-3468 revealed that the first reaction of nitroreduction of TNT resulting in formation of 2-amino-4,6-dinitrotoluene (2A) and 4-amino-2,6-dinitrotoluene (4A) became more active in case of nitrate respiration as compared to oxygen respiration; a TNT decrease was 100 and 66%, respectively. The same tendency but much more pronounced was observed at the next stage of nitroreduction that lead to 2,4-diamino-6-nitrotoluene (2,4DA). On the contrary, aerobic conditions are more preferable for the subsequent destruction of 2,4DA.

[Antitumor action of Ser. marcescens nuclease covalently bound to soluble dextrans].

The antitumor effect of Ser. marcescens nuclease, modified by covalent binding using the method of diazocoupling with m-aminobenzyloxymethyl dextran of molecular weight 20 000, 40 000, 60 000, exceeds 3--4 times the antitumor effect of the native enzyme in relation to Ehrlich ascites carcinoma in contact tumor cells exposure. In intramuscular injection of the enzyme the nuclease preparation modified by dextran of molecular weight 40 000 showed the greatest antitumor activity against Ehrlich carcinoma and sarcoma 37.