Effect of Sodium Laurylbenzenesulfonate on Escherichia coli

The antimicrobial effect of sodium laurylbenzenesulfonate (LBS)on the growth of Escherichia coli was examined, The period of lag phase in growth curve was extended more intensely with increasing amount of LBS added to the culture, and rapid decrease of turbidity at 660 nm of the culture was observed when large amount of LBS (50μg/m1)was added to it at the logarithmic phase.However,LBS of any concentration used could not inhibit the grnwth of E.coli completely.The addition of LBS (1-100μg/ml)to the suspension of spheroplasts resulted in a rapid decrease of turbidity at 660 nm, on the other hand,the same phenomenon was notfound in intact cells suspension. Furthermore,LBS addition to both intact cells and spheroplasts suspensions resulted in a rapid release of some cell nstituents. Leakages of them were more marked in spheroplasts than in intact cells. The effect of LBS on oxygen uptake by intact cells was also examined. Lt was found that LBS inhibited the oxygen uptake attended by oxidation of cellular respiratory substrates in cells