Biodegradation kinetics of phenol and catechol using Pseudomonas putida MTCC 1194

Biological degradation of phenol and catechol by a bacterial strain of Pseudomonas putida (MTCC 1194) in basal salt medium (BSM) was investigated in shake-flask experiments at 29.9 +/- 0.3 degreesC and pH of approximately 7.1. The lyophilized cultures of P putida (MTCC 1194) were revived and exposed to increasing concentrations of phenol, and catechol in shake-flasks. This bacterial strain could be acclimatized to the concentrations of 1000 and 500 mg/l for phenol and catechol, respectively, over a period of three months. The higher the concentration of phenol or catechol, the longer was the lag period. The well-acclimatized culture of P putida (MTCC 1194) degraded the initial phenol concentration of 1000mg/l and initial catechol concentration of 500mg/l completely in 162 and 94h, respectively. Both the phenol and catechol were observed to be the inhibitory compounds. Monod's and linearized-Haldane's model could not represent the growth kinetics over the studied concentration range. However, Haldane's growth kinetics model could be fitted to the growth kinetics data well for the entire concentration range. Further, the decay coefficients have been found to be 0.0056 and 0.0067 h(-1) for the growth on phenol and catechol, respectively. Besides, the yield coefficient for the growth on phenol and catechol were found to be 0.65 and 0.50 mg/mg, respectively. It is our view that the above information would be useful for modeling and designing the units treating phenol- and catechol-containing wastewaters. (C) 2004 Elsevier B.V All rights reserved.