Bioactivity of K12A, K12S and K12T producers against various Gram-positive targets.

Values are the mean of triplicate deferred antagonism assays and represent zone of inhibition (diameter of zone minus diameter of bacterial growth) expressed as a percentage compared to that of the wild-type nisin producer at 100%. S.D.: Standard Deviation; Relative Standard Deviation<10% for each given value. All values in bold reached statistical significance compared to nisin control (K) (Student's t-test: P<0.05). Strains marked with an asterisk are drug resistant isolates.