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

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 1400 mg/L phenol, 800 mg/L m-cresol and 150 mg/L 4-chlorophenol (4-CP) as sole carbon and energy source within 60 h, 40 h and 60 h, 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 300 mg/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 fifi (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.

► Isolation and characterization of Pseudomonas sp. cbp1-3 were performed. ► The strain degraded phenol, m-cresol and 4-chlorophenol as sore carbon source. ► Interactions of substrates in dual- and ternary-substrate systems were investigated. ► Kinetic models for ternary-substrate systems were proposed and evaluated.