PubMed Health⌕ Search

Biomedical subjects

A D Nekliudov

Publications and source records attributed to A D Nekliudov.

At least 19 recordsLinked to original sources
PubMed1991

[Effect of the methods of sterilization on the quality of nutrient media and on the level of antibiotic production].

It was shown that conditions for heat sterilization of nutrient media for biosynthesis of antibiotics had an impact on their biochemical composition and activity of a fermentation broth in production of penicillin and erythromycin. The temperature of 120 degrees C and the time of 25 minutes proved to be optimal for sterilization of the media in regard to both preservation of their biochemical composition and providing of the maximum antibiotic productivity on the one hand and maintenance of the sterility during the fermentation process on the other hand.

Amino Acids↗
PubMed1988

[Isolation of 5-benzyl hydroxytryptophan enantiomers by using microbial aminoacylase].

The process of asymmetric deacylation of an acetyl derivative of 5-benzyl hydroxytryptophan racemate in the presence of native microbial aminoacylase was studied. The effect of pH, temperature, concentration of the enzyme and substrate were investigated. Conditions for preparation and isolation of individual amino acids were defined by optimization of N-Ac-DU-5-BOT hydrolysis.

5-Hydroxytryptophan↗
PubMed1988

[Conditions for immobilizing Streptomyces erythreus in a calcium alginate gel and the apparatus setup for the process].

A laboratory unit for production of calcium alginate gel granules with immobilized microorganisms is described. It provides sterile production of particles from tens micrometers to 2 mm in diameter. Expediency of using biocatalysts in the form of fine granules is exemplified with a number of immobilized microorganisms. Conditions for immobilizing the erythromycin producing organism by its incorporation into the calcium alginate gel were studied. Viability of the actinomycete in the gel was shown by consumption of the nutrients and biosynthesis of the antibiotic.

Alginates↗
PubMed1985

[Isolation of protein hydrolysates by using immobilized bacterial peptide hydrolases].

Preparation of medical protein hydrolysates with the use of complete hydrolysis of proteins by bacterial enzyme complexes, such as protosubtilin G10x and bacterial peptidase immobilized on aminosilylated alumina was shown to be possible. The activity, thermostability and substrate specificity of the heterogeneous biocatalysts were studied. The integral kinetics of the hydrolysis of sodium caseinate and peptides included in partial acid and enzymatic casein hydrolyzates and blood was investigated. The engineering approaches to mathematical simulation of the bioproteolysis kinetics and the results of their use in processing of the experimental data are discussed.

Aluminum Oxide↗
PubMed1985

[Sorption of amino acids from aqueous solutions on activated charcoal].

Various methods for quantitative description of amino acid sorption from solutions for parenteral nutrition on activated charcoal were studied under dynamic and static conditions. With the use of the well-known Freindlich and Langmuir absorption isotherms it was shown to be possible to describe in a simplified way the complex multicomponent process of sorption of the amino acids and to estimate their loss at the filtration stage.

Absorption↗
PubMedDate not supplied

[Hydrolase from Xanthomonas rubrilineans for synthesis of cefalexin].

The use of peptide hydrolase (EC 3.4.13.1) from Xanthomonas rubrilineans for synthesis of the antibiotic cephalexin from 7-aminodesacetoxycephalosporanic acid was studied. The optimum conditions for production of cephalexin were determined, and the yield exceeded 80%. A method for monitoring the synthesis of this antibiotic synthesis by means of a conventional amino acid analyzer is proposed.

Cephalexin↗
PubMedDate not supplied

[Preparation and purification of protein hydrolysates].

Recent achievements in the technology of production of protein hydrolysates are reviewed. Approaches to description of the mechanism of hydrolysis and the possibility of purification of hydrolysates for their use in the food, medical, forage, and microbiological industries are discussed.

Hydrolysis↗
PubMedDate not supplied

[Proteolytic activity of the enzyme complex of the mammalian pancreas in comparison with pancreatin].

The proteolytic activity and thermal stability of the enzyme complex of cell suspension from pig and bovine pancreas glands was compared with those of pancreatin. The enzyme complex displayed the highest thermal stability and activity at 50 degrees C. The kinetic constants, energies of activation and inactivation of the enzyme complex, and pH optimum (7.0 +/- 0.1) at which this complex had the maximum proteolytic activity were determined. Pancreatin had a pH optimum of 8.0 +/- 0.1.

Animals↗
PubMedDate not supplied

[Characteristics and use of protein hydrolysates (review)].

Properties of protein hydrolysates and possible uses of these substances in research and various branches of industry are considered. The main problem discussed in this paper is the relationship between the degree of protein conversion and characteristics (structural-functional and physicochemical) of hydrolysates.

Protein Hydrolysates↗
PubMedDate not supplied

[Isolation and characteristics of immobilized aminoacylase from Streptoverticillium olivoreticuli].

Immobilization of aminoacylase from Streptoverticillium olivoreticuli by incorporation into acrylamide gel has been investigated. The data showed that the process should be carried out at constant pH. Thermal inactivation of the immobilized enzyme under the reaction conditions was studied. The kinetics of enzymatic stereospecific deacylation of N-acetyl-DL-phenylalanine was analyzed. The results of this study may be used in the synthesis of amino acid enantiomers.

Amidohydrolases↗