Abstract

Six strains of Zymomonas mobilis were evaluated in relation to the ability of producingbacteriocin against Gram-negative and Gram-positive bacteria, including three strains ofEscherichia coli, one strain of Salmonella enteritidis and one strain of Staphylococcus aureus and Streptococcus faecalis. Two culture media and temperatures of 30 and 37°C were effective in the expression of the inhibitory activity and there was no involvement of bacteriofages or acid compounds in this activity. The bacteriocin was characterized as a thermosensitive protein released into the culture medium. The kinetics of bacteriocin production showed that the inhibitory activity was detected during the late logarithmic phase and maintained during the stationary phase. The fingerprinting pattern of the producer strains showed no polymorphism employing the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique; however using randomly amplified polymorphic DNA (RAPD), the differentiation of the six strains in different degrees of similarity, was found.

Key words: Zymomonas mobilis, bacteriocin, RAPD.