Amino-acids highlighted in grey indicate variations when compared to the nisin A (the first nisin variation

to be discovered) references. The complete amino-acid sequencesfrom the 9 wild strains have been deposited in GenBank (accession numbers KF146295 to KF146303, respectively). Table 3 shows the inhibitory activity of the nis positive Lactococcus isolates against several microbial targets. It can be observed that the isolates presented inhibitory activity mainly against the tested Gram positive bacteria, and lower frequencies of inhibition against Gram negative bacteria. These results indicate that the bacteriocins produced by the tested LAB isolates have interesting Alvelestat clinical trial antimicrobial activities, highlighting the relevance of raw goat milk as a source of bacteriocinogenic

strains [23]. In addition, the obtained results indicate that the PF-02341066 ic50 variations in nisin structure predicted in the present study (Figure 3) did not affect the antimicrobial activity of the isolates. Considering the main characteristics of bacteriocins, the inhibitory activity against the tested Gram negative bacteria must be due to non-specific antimicrobial substances produced by the LAB strains, such as organic acids or peroxide [24, 34]. Table 3 Inhibitory activity (diameters of inhibition halos, mm) of nis positive Lactococcus isolates obtained from raw goat milk against target microorganisms, identified by the spot-on-the-lawn methodology Target genus Species/serotype Origin* nispositive isolates       GLc04 GLc05 GLc08 GLc14 GLc18 GLc19 GLc20 GLc21 GLc03 Lactobacillus L. sakei ATCC 15521 11 13 9 9 5 11 0 0 5 Lactococcus L. lactis subsp. lactis ATCC 7962 11 9 8 7 0 7 0 0 0   L. lactis subsp. lactis

GLc18, wild strain, present study 13 11 11 11 0 12 0 0 7   L. lactis subsp. lactis GLc22, wild EGFR inhibitor strain, present study 13 11 11 7 7 10 7 7 7 Listeria L. monocytogenes ATCC 7644 11 11 11 9 15 13 7 7 9   L. monocytogenes ATCC 15313 9 9 7 7 0 7 7 5 10   L. monocytogenes 60, wild strain, beef origin 15 14 12 9 7 13 5 5 5   L. inoccua 76, wild strain, beef origin 5 5 5 5 5 5 5 5 9 Staphylococcus S. aureus ATCC 12598 9 7 7 7 7 5 7 7 7   S. aureus ATCC 14458 9 7 7 7 7 9 11 7 7   S. aureus ATCC 29213 8 7 7 7 7 7 9 0 7   S. aureus 27AF1, wild strain, cheese origin 9 9 9 7 5 11 7 0 9   S. aureus 27ST1, wild strain, cheese origin 9 9 9 7 5 7 11 7 9   S. aureus 26BP6, wild strain, cheese origin 13 13 14 7 7 13 7 0 7 Escherichia E. coli ATCC 11229 0 0 0 0 0 0 0 0 0   E. coli ATCC 00171 0 0 0 0 0 0 0 0 0 Pseudomonas P. aeruginosa ATCC 27853 5 5 5 5 0 0 5 0 0   P. fluorescens ATCC 10038 5 5 5 0 0 0 0 0 0 Salmonella S. Typhimurium ATCC 14028 7 7 5 5 0 0 0 0 0   S. Cholerasuis 38, wild strain, beef origin 0 0 0 0 0 0 0 0 0   S. Enteritidis 258, wild strain, poultry origin 7 7 7 5 5 5 5 5 0   S.