Also 100% degradation of this concentration of gallic acid was observed in 72 h (data not shown).Kouroutzidou et al.reported degradation of 1g/L gallic acid in 23 days by using anaerobic sludge. The requirements of less time for gallic acid degradation and ability to sustain higher concentrations of gallic acid, explores the potential of PPO enzyme. According to Robles et al.,the total phenolic compound concentration in olive mill wastewater is 1.6 _0.18 g/L,but it may vary depending on the type and origin of the effluent. However, owing to the large volume and high pollution potential of the phenolic-rich efeffluent, use of PPO enzyme for phenolic compound degradation is an attractive approach to industrial needs. There are number of reports in the literature on by biodegradation of phenolic compounds. An advantage of enzymatic approach over microbial degradation is that enzymes can react with a broad range of aromatic pollutants under dilute conditions. Our results indicate that by using PPO enzyme the rate of removal of pollutants is quite fast and is less sensitive to operational upsets as compared to the microbial flora.Duran and Esposito also reported similar observations.