E. coli cells were grown in the Luria Bertani Miller’s broth
overnight at 37 C till reaching the exponential phase. The cell
concentrations were determined by cell counting with a hemocy-
tometer under an optical microscope. E. coli cells were then
harvested by centrifugation at 5000 rpm for 10 min. The supernatant
was discarded after centrifugation and the E. coli sediment was
used for inoculation of milk samples.