The effect of selected amino acids on the antimicrobial activity of furanomycin. The indicated amino acids were added to aliquots of P. fluorescens SBW25 culture filtrate to give a final amino acid concentration of 10 mM. The resulting solutions were filter sterilized and tested for antimicrobial activity against D. dadantii in our agar diffusion assay as described in the Methods section. The areas of the cleared zones in the bacterial lawns surrounding the central well containing the test solutions are the averages of three replicates. The error bars represent Standard Error of the Mean values.