[Study on method of acclimation and screening of a highly effective toluene-degrading bacterium]

To establish a highly effective toluene-degrading bacterium acclimation and screening method.

Samples were collected from activated sludge in brewery and dye plant. Toluene-degrading bacteria were screened by enrichment and acclimation process, and then were isolated and purified by four methods. TOL plasmid was determined by plasmid rapid detection method. Growths of degrading-bacteria were detected by A600 assay and toluene-degrading abilities were measured by head-space gas chromatography. The highly effective degrading bacteria were isolated and identified by the Gram staining, morphological observation and sequence analysis of 16S rDNA.

More abundant species of degrading bacteria were isolated from activated sludge in brewery plant than those in the dye plant. Degrading bacteria grew well in a sealed-jar. The highly effective degrading bacterium was identified as Pseudomonas aeruginosa. 99.2%-Toluene were degraded in 48 h with initial concentration of 500 mg/L at 28 degrees C, pH 7.0.

The sealed-jar incubation in combination with plasmid rapid detection and head-space gas chromatography was applied to identification of degrading bacterium and this method was accurate, time-saving and effective.