Phenolic content and antibacterial activity of olive oil waste waters

The antibacterial effects of olive oil wastes from traditional installations (TM), wastes from modern installations (CM), and wastes from an evaporation pool (EP) were assayed with a soil bacterium (Bacillus megaterium ATCC 33085). Irrespective of the origin, fresh wastes showed higher antimicrobial activity than those from evaporation pools. Among several extractants, ethyl acetate and n-propanol were the most effective organic solvents in the recovery of the antimicrobial activity from wastes. No antimicrobial activity was recovered by hexane extraction. Extracts from evaporation pool wastes showed no antibacterial activity. A good correlation between phenolic content and antimicrobial activity was found.