In situ degradation of phenol and promotion of plant growth in contaminated environments by a single Pseudomonas aeruginosa strain

For bioremediation of contaminated environments, a bacterial strain, SZH16, was isolated and found to reduce phenol concentration in a selective medium. Using the reaction vessel containing the soil mixed with phenol and bacteria, we found that the single strain degraded efficiently the phenol level in soil samples. The strain was identified as Pseudomonas aeruginosa on the basis of biochemical tests and by comparison of 16S rDNA sequences, and phosphate solubilization and IAA production were not observed in the strain. Simultaneous examination of the role of strain SZH16 in the plant growth and phenol biodegradation was performed. Results showed that inoculation of the single strain in the phenol-spiked soil resulted in corn growth promotion and in situ phenol degradation and the increase in plant biomass correlated with the decrease in phenol content. Colonization experiments showed that the population of the SZH16 strain remained relatively constant. All these findings indicated that the corn growth promotion might be due to reduction in phytotoxicity, a result of phenol biodegradation by the single strain SZH16. Furthermore, the strain was found to stimulate corn growth and reduce phenol concentration simultaneously in phenol-containing water, and even historically contaminated field soils. It is attractive for environment remediation and agronomic applications.