Vasilchenko A.S., Valyshev A.V.
OPTIMIZATION OF A CULTURE MEDIUM COMPOSITION AS APROACH TO ISOLATION OF BACTERIOCINS ^{[№ 12 ' 2017]}
Antimicrobial peptides of bacterial origin can be considered as effective food preservatives, as well as therapeutic agents. The first difficulties in the study of these substances begin at the stage of bacteriocin`s isolation from the culture medium of the producer microorganism. A simple and affordable approach for optimizing isolation of bacteriocins from metabolites of microorganisms is presented. In this study a strain of E. faecium ICIS 7 was used as bacteriocin producer. Bacteria were cultured on four different media comprising two commercial medium and two semisynthetic. Isolation of bacteriocins was carried out by reversed-phase liquid high-performance chromatography. At the first stage, the bacterial growth parameters on various media were estimated and bacteriocin`s production was evaluated semi-quantitatively. At the second stage chromatographic profiles were obtained and compared. Finally it was shown that using a simple media consisting of the yeast extract only, makes it possible to produce bacteriocins and subsequently simplify their chromatographic purification. Thus, it can be concluded that the yeast extract is an ingredient available to most laboratories, while the components for the preparation of the chemical-defined medium are still quite expensive chemical reagents (amino acids, nucleic acids etc.). The use of a yeast extract for the cultivation and production of bacteriocins significantly reduces the cost of isolating the target polypeptide.

Bukharin O.V., Chainikova I.N., Smolyagin A.I., Valyshev A.V., Perunova N.B., Vlasova E.V., Kalinina T.N.
CHARACTERISTICS OF LOCAL BOWELS IMMUNITY AND MICROBIOCENOSE OF PATIENTS WITH SALMONELLOSIS INFECTION ^{[№ 5 (app.1) ' 2005]}
It was revealed that evident numerical and qualitative damages of microbiocenose condition of thick bowels of patients with salmonellosis are accompanied with synchronous change of local immunity characteristics in coprophiltrates and saliva.