Antimicrobial effects of green tea polyphenols on thermophilic spore-forming bacteria

The inhibitory action of tea polyphenols towards the development and growth of bacterial spores was examined. Among the tested Bacillus bacteria, tea polyphenols showed antibacterial effects towards Bacillus stearothemophilus , which is a thermophilic spore-forming bacterium. The heat resistance of B . stearothermophilus spores was reduced by the addition of tea polyphenols. Clostridium thermoaceticum, an anaerobic spore-forming bacterium, also exh ibited reduced heat resistance of its spores in the presence of tea polyphe nols. (-)-Epigallocatechin gallate, which is the main component of tea poly phenols, showed strong activity against both B. stearothermophilus and C. t hermoaceticum. The heat resistance of these bacterial spores was more rapid ly decreased by the addition of tea polyphenols at high temperatures.