Growth Promoting and Inhibiting Effects of Spices on E. coli

Abstract

The present work was carried out to account for the dual, stimulatory and inhibitory, action of some spices on bacterial growth depending on its concentrations, which was noticed during the study of anti-bacterial effects of spiced. The results obtained on E. coli were as follows: (1) Besides a well-known growth inhibiting effect of garlic, a commercial garlic powder sample and diluted garlic juice promoted the growth of E. coli, due to the presence of scordinine. (2) Thymol in thyme was a growth inhibiting substance, while tannic acid, one of tannic substances in thyme, at low concentrations and ascorbic acid in fresh spices were assumed to be growth promoting factors.