Peptide synthesis and antimicrobial screening
The peptides in the created peptide library were synthesized based on the SPOT technique and pure peptides (≥95% purity) were synthesized on resin using solid phase Fmoc peptide chemistry.16 The 135 peptides in the peptide library  were screened for antimicrobial activity using both luminescent (Pseudomonas aeruginosa strain H1001)34 and non-luminescent (epidemic methicillin resistant S. aureus EMRSA-15, Sal. typhimurium and E. coli K12) bacterial strains. Activity against non-luminescent bacteria strains was assessed by fluorescence readings (excitation/emission spectra of 560/590 nm) after the addition of resazurin dye (100 µm final concentration). The results from the screen were analysed using the MATLAB extension Gait-CAD as previously described.35 Concentration values with a 75% reduction of luminescence or fluorescence (IC75) in relation to untreated controls were computed. Three peptide activity classes: active (IC75 ≤ 0.25), semi-active (0.25 < IC75 ≤ 0.50) and inactive IC75 > 0.5 were assigned against all microorganisms.