Antagonistic Activities of the Rumen Bacteria Enterococcus-Faecium and Staphylococcus-Warneri

Veterinarni Medicina 38, 1993, 267-274

The bacterial strains E faecium and S. warneri were tested for their antagonistic activities, and/or for the antimicrobial spectrum of bacteriocin-like substances produced by these bacteria. Isolates of rumen and non-rumen origin were used as indicator strains (Tab. I). All the isolates (except the strains SW48 and EF24c as indicators of rumen origin) produced bacteriocin-like substances inhibiting the growth of at least one of the series of the nine indicators used while clear inhibition zones 2 - 10 mm prevailed (Tabs. II, III). Among the enterococci, the inhibition of non-rumen indicators was more intensive in comparison with the indicators of rumen origin, but the inhibition zones were only 2 - 5 mm. In general, the staphylococci showed the antagonistic activity with the lower antimicrobial spectrum in comparison with the enterococci. None of the tested strains inhibited the growth of the indicator E. faecium A26. The summary results show that the growth of both gram-positive and gram-negative bacteria was inhibited. The prolonged cultivation time did not influence the antagonistic activity of the tested strains. In the strains EF35, SW34 and SW98, the antagonistic activity was maintained after trypsin treatment. But in the other strains, this treatment led to the loss of the antagonistic activity. The use of pronase P resulted in the loss of the activity in the strains SW24, EF35 and EF26/142. The use of pronase P did not lead to the loss of the activity in the other tested isolates (Tab. IV). Tle temperature of 60-degrees-C did not induce the loss of the inhibition activity only in the strains EF 35, EF24/232 and EF24c (Tab. IV). The specification of the bacteriocin-like substances produced by the tested strains to the group of low or high molecular bacteriocins requires a detailed analysis of amino acids in the peptide chain of these substances after their purification

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