Mundticin KS: Characterization and Production Method

Abstract

The paper aims to develop a method for the single-stage purification of mundticin KS and to study its physicochemical and antimicrobial properties. Mundticin produced by strain Enterococcus mundtii B-8398 and belonging to class IIa bacteriocins was obtained by adding 10% of the CM Sephadex C-25 sorbent to the culture medium before cultivation. At the end of cultivation, the sorbent was collected and packed into a column followed by a one-step elution. As a result, a fraction containing mundticin KS was obtained with a purification quality of about 70%. The activity of mundticin KS remained stable over a wide range of pH and temperatures. It is completely inactivated by such enzymes as proteinase K and α-chymotrypsin and partially by trypsin; however, such enzymes as amylase, lipase, and papain do not have any effect on its activity. Mass spectral analysis, electrophoresis, and DNA sequencing showed the high range similarity of mundticin KS produced by strains E. mundtii B-8398 to other previously studied mundticins. The antibacterial activity of mundticin KS was recorded ageist all tested strains of Listeria spp., Enterococcus spp., and Clostridium perfringens in nanomolar concentrations. In addition, mundticin KS inhibits the growth of most tested Gram-positive food-borne pathogens. By the sorbent cultivation method, it was possible to increase the yield of mundticin KS by 2,9 times compared to the control.