Tow legume proteins (cowpea and common bean proteins) were isolated and esterified with methanol in the presence of hydrochloric acid for 10 h at 4°C to give esterification extent 82% and 79%; respectively. Esterification raised the pIs (iso-electric points) of legume proteins from pH 4 for the native legume proteins, to pH 6 in the case of cowpea protein and pH 8 in the case of common bean. Applying methylated proteins at four different concentrations (0.5, 0.75,1 and 2 mg/ml) to Petri dishes containing nutrient agar infected with two pathogenic Gram- negative (Enterobacter cloacae and Serratia marcescens) and Gram- positive bacteria (Listeria monocytogenes) gave rise to concentration-dependent inhibition zones.