In the present study it was found that LPS17 and LD219 produced the widest inhibition zones when S. aureus was used as
an indicator. In addition, for a third screening against E. coli inhibition, only 7 strains exhibited inhibition zone diameters on agar (Table 1). The strains which showed widest zones of inhibition against E. coli were LPS04. Roth and Keenan (1971) reported that lactic acid is able to cause sub-lethal injury to E. coli, and similar properties have also been assigned to acetic acid (Przybylski & Witter, 1979). Indirect evidence suggests that such injury involves disruption of the LPS layer. A permeabilizer function of lactic acid