Kinetic studies of phenol degradation by Rhodococcus sp. P1. II. Continuous cultivation

The degradation of phenol by Rhodococcus sp. P1 was studied in continuous culture systems. The organism could be adapted by slowly increasing concentration, step by step, up to 30.0 g.l-1 phenol in the influent. The degradation rate reached values of about 0.3 g.g dry mass-1.h-1. Large step increases in phenol concentration and addition of further substrates (e.g., catechol) were tolerated up to a certain concentration. With increasing dilution rate and increasing inlet phenol concentration the stability of the system decreased. Nomenclature: D--Dilution rate, h-1, Dc--Critical dilution rate, h-1, Dx--Yield, g dry mass.l-1.h-1, Ks--Monod saturation constant, g.l-1, S--Growth-limiting substrate concentration in culture broth, g.l-1, SR--Growth-limiting substrate concentration in feed, g.l-1, mean--Biomass concentration in culture broth, g.l-1, YS--Yield constant, g cell dry mass.g substrate-1, mu--Specific growth rate, h-1, mu max--Maximum growth rate, h-1.