[Comparative characteristics of the metabolism of E. coli cells with various activity of penicillin acylase].

A correlation between the synthesis and secretion of penicillin acylase (PA; EC 3.5.1.

[Study of amino acid utilization by isogenic strains of Escherichia coli in relation to the culture growth and biosynthesis of penicillin amidase].

Dynamics of free amino acid utilization by isogenic strains of Escherichia coli differing in intensity of their growth and levels of penicillin acylase biosynthesis in media containing corn steep liquor or peptone was studied. It was shown that in both the media some amino acids such as serine, threonine, glutaminic and asparaginic acids were actively utilized by the strains mainly during the culture intensive growth while others such as glycine, alanine and tyrosine were actively utilized during the enzyme biosynthesis. Intensively utilized arginine and proline were probably used for the growth and biosynthesis.

[Regulation of the biosynthesis of aminoacylase and pigments by strains of Actinomyces of the genus Streptoverticillium].

For using actinomyceteous extracellular aminoacylase in production of optically active amino acids it is necessary to have the fermentation broth with lowered contents of extracellular pigments whose accumulation dynamics in the process of the strain growth correlates with the dynamics of the enzyme biosynthesis. The results of the studies showed that it was possible to regulate biosynthesis of the aminoacylase and pigments in the direction of increasing the enzyme production and decreasing the pigment formation by using a medium of the respective composition and providing the respective high temperature and sufficient aeration for the strains.

[Differences in the cytotoxicity mechanisms of pancreatic and microbial ribonucleases].

The effect of pancreatic and microbial ribonucleases (RNAses) on incorporation of labeled precursors, i. e. 14C-uridine, 14C-thymidine and 14C-glycine into the biopolymers of transplantable cell cultures, as well as their effect on radioactivity of the acid insoluble fraction of the cells labeled with 14C-orotic acid was studied.

[Enzyme preparations for research on protein hydrolysates and amino acid mixtures not containing peptides].

Some properties and the hydrolysing ability of two novel enzyme preparations, a proteolytic preparation "C" from Acremonium chrysogenum (Cephalosporium acremonium) and a peptidase preparation (the producer from the family Pseudomanadaceae), are described. The preparations can be used for obtaining protein hydrolysates with different ratios of free amino acids and peptides. The protein hydrolysis with the preparation "C" enables one to obtain hydrolysates containing 13-18% of free amino acids.