Potential effluent oil mills and antibacterial activity polyphenols against some pathogenic strains

The recovery of polyphenols from olive mill wastewaters (OMWs) provides the double opportunity to obtain high-added value biomolecules and to reduce the phytotoxicity of the effluent. The purpose of this study is to gain information about the hygienic quality of the raw material by performing a microbiological analysis of olive mill wastewater, from an extraction system of three phases. The determination of total coliforms,fecal coliforms,aecal streptococci, and another group of microorganisms have been explored, namely yeasts, molds and total aerobic mesophilic flora. We examined the results of the confrontation of olive mill wastewater polyphenols with certain strains known for their pathogenicity, and the minimum concentrations inhibiting bacteria and the minimal bactericidal concentration (MBC) were determined by the dilution method. Polyphenols are particularly the delipidated fraction of OMW extracts according to liquid-liquid phase. The overall yield is 1.367 +/- A 0.108 %. The quantitative estimation of total polyphenols was assessed by the colorimetric reagent Folin-Ciocalteu, gallic acid and tyrosol, tannic acid and total flavonoids catechin (the method using aluminum trichloride). The results of microbiological analysis confirmed that there is no fecal contamination. For the in vitro bioassay, polyphenols showed a variable antimicrobial activity against six bacteria: Escherichia coli, Proteus sp., Pseudomonas aeruginosa, Enterroccus feculis, Staphylococcus aureus, and Klebsiella pneumoniae. This variability depends essentially on the microorganism tested and the nature of the product tested. Indeed, we found complete inhibition of the growth of Proteus sp. and E. fecalis by the sinks method. Some microorganisms were sensitive to phenols with MBC values between 1/50 and 1/25.