Kinetics of batch microbial degradation of phenols by indigenous binary mixed culture of Pseudomonas aeruginosa and Pseudomonas fluorescens

Abstract

The potential of various organisms to metabolise organic compounds has been observed to be a potentially effective means in disposing of hazardous and toxic wastes. Phenolic compounds have long been recognised as one of the most recalcitrant and persistent organic chemicals in the environment. The bioremediation potential of an indigenous binary mixed culture of Pseudomonas aeruginosa and Pseudomonas fluorescens was studied in batch culture using synthetic phenol in water in the concentration range of 100-500 mg/litre as a model limiting substrate. The effect of initial phenol concentration on the degradation process was investigated. Phenol was completely degraded at different cultivation times for the different initial phenol concentrations. Increasing the initial phenol concentration from 100 mg/litre to 500 mg/litre increased the lag phase from 0 h to 18 h and correspondingly prolonged the degradation process from 24 h to 96 h. There was decrease in biodegradation rate as initial phenol concentration increased. Fitting data into three different kinetic models (Monod, Haldane, and Yano and Koga) showed that the difference in fit between the models was very small and thus statistically insignificant. Thus, the Yano and Koga model has been used to 178 interpret the free cell data on phenol biodegradation. The kinetic parameters have been estimated up to initial phenol concentration of 500 mg/litre. The r smax decreased, K s and K i increased with higher concentration of phenol. The r smax has been found to be a strong function of initial phenol concentration.

Biological removal of phenol from wastewaters: a mini review

“…Most of the isolated bacteria showed a good ability of degradation of phenol, where Pseudomonas and Acinetobacter showed 0.8-0.9 g/L, and Kelibsiella, Citrobacter and Shigella showed 0.6-0.7 g/L and the rest showed 0.2-0.3 g/L of phenol degradation. Agarry et al (2008) studied the bioremediation potential of an indigenous binary mixed culture of Pseudomonas aeruginosa and Pseudomonas fluorescence in batch culture using synthetic phenol in water in the concentration range of 100-500 mg/L as a model limiting substrate. The effect of initial phenol concentration on the degradation process was investigated.…”

Evaluation of Microbial Systems for Biotreatment of Textile Waste Effluents in Nigeria: Biodecolourization and Biodegradation of textile Dye

“…Moreover, the mixed culture had a higher percent decolourization (72%) of textile waste effluents with 30 mg/L dye concentration than the individual isolates. The advantages of employing mixed cultures (microbial consortium) as opposed to pure cultures in bioremediation have been demonstrated (Agarry et al, 2008).…”

Comparison of different models of substrate inhibition in aerobic batch biodegradation of malathion

“…Carrera et al (2004) found that the Aiba equation was the best model to describe ammonium inhibition of the nitritation process in a suspended biomass system and an immobilized biomass system, whereas the Haldane equation (similar to the Andrews equation) was the best model to describe nitratation inhibition by nitrite in both systems. Agarry et al (2008) investigated the kinetics of phenol degradation using an indigenous binary mixed culture of Pseudomonas aeruginosa and Pseudomonas fluorescence and showed that the Yano and Koga equation is the best model to describe the phenol biodegradation. On the other hand, the substrate inhibition observed during the biodegradation of phenol by a mixed microbial culture was explained by Saravanan et al (2008) using the Haldane and Han-Levenspiel substrate inhibition models.…”