MULTI-SUBSTRATE GROWTH-KINETICS OF PSEUDOMONAS-PUTIDA FOR PHENOL REMOVAL

The biodegradation of phenol by a pure culture of Pseudomonas putida w as investigated in a continuously fed stirred-tank reactor, under aero bic conditions. The dilution rate was varied between 0.0174 h(-1) and 0.278 h(-1), covering a wide range of dissolved oxygen and the inhibit ion region of phenol. Through non-linear analysis of the data, a dual- substrate growth kinetics, Haldane kinetics for phenol and Monod kinet ics for oxygen, was derived with high correlation coefficients. Respec tive biokinetic parameters were evaluated as mu(m) = 0.569 h(-1); K-p = 18.539 mg/l, K-i = 99.374 mg/l, K-o = 0.048 mg/l, Y-x/p = 0.521 g mi croorganism/g phenol and Y-x/o = 0.338 g microorganism/g oxygen, being in good agreement with other studies in the literature. Maintenance f actors for both phenol and oxygen were calculated for the first time f or P. putida while the saturation coefficient for oxygen, K-o, was gen uinely evaluated from the constructed model, not imported or adapted f rom other studies as reported in the literature. All pertinent biokine tic parameters for P. putida have been calculated from continuous syst em data, which are most appropriate for use in continuous bioprocess a pplications.