Substrate interactions and kinetics study of phenolic compounds biodegradation by Pseudomonas sp. cbp1-3

Abstract

A new strain cbp1-3 was isolated from activated sludge of a coking plant in Tianjin and identified as Pseudomonas sp. based on physiological and 16S rRNA gene sequence analysis, which could completely degrade 1400mg/L phenol, 800mg/L m-cresol and 150mg/L 4-chlorophenol (4-CP) as sole carbon and energy source within 60h, 40h and 60h, respectively. Investigation on substrate interactions in the biodegradation of mixed phenols indicated that phenol and m-cresol exhibited a mutual inhibition to each other, and they (only below 300mg/L) both promoted the 4-CP biodegradation. However, 4-CP strongly inhibited the biodegradation of other phenols in their mixtures despite of the low concentration. Further analysis showed that the newly proposed kinetic model for cell growth on ternary substrates fitted the experimental data very well. And sensitivity analysis suggested that substrate interaction coefficients fi (i=12, 13 and 23) of the models were the most sensitive parameters. Finally, yield coefficient, calculated for all conditions, taken as a whole, followed an allometric decline pattern with the increase of substrate concentration.