BACKGROUNDThe main objective of this study was to examine the growth and phenol degradation kinetic parameters for bacteria isolated from activated sludge that could register growth on phenol as high as 1410mgL(-1). RESULTSPhenol-degrading bacteria of the Alcaligenes, Providencia, Acinetobacter and Aeromonas genera were prevalent in the activated-sludge tank. The degradation rate was affected by the phenol concentration; the B9-1 and B8-1 Alcaligenes faecalis strains showed rates of 0.037 and 0.038gL(-1)h(-1) when exposed to up to 940mgL(-1) phenol, respectively. The B6-2, G1, and H1-1 A. faecalis strains showed rates of 0.036, 0.042 and 0.036gL(-1)h(-1), respectively, when exposed to up to 1128mgL(-1), and Acinetobacter johnsonii D1 and A. faecalis D3 strains showed rates of 0.058 and 0.049gL(-1)h(-1), respectively, when exposed to 1410mgL(-1) phenol. The growth kinetic parameters adjusted by genetic algorithm (GA) and the Haldane equation ranged within (m)=0.12-0.55h(-1), (max)=0.07-0.29h(-1), K-s=25-483.8mgL(-1), and K-i=153.7-2582.6mgL(-1). CONCLUSIONSThe high values of (max), K-i, and Y-X/S adjusted by GA showed that the studied strains are able to tolerate and degrade higher phenol concentrations compared with levels reported for single bacterial strains. (c) 2014 Society of Chemical Industry