Characterization and application of a newly isolated pyrene-degrading bacterium, .

PL5 (PL5) was newly isolated from soil sample and was identified by 16S rDNA sequence analysis. The strain PL5 had a high potential to degrade pyrene (PYR) in both liquid solution and soil and was able to degrade 51.8% of PYR at 25 °C and pH 7.0 condition within 10 days. At 25 °C, the ability of strain PL5 to degrade PYR at different pH values followed the following order pH 6.0 > pH 7.0 > pH 8.0 > pH 9.0. Degradation of total PYR was 56.5 and 51.8% after 10 days at pH 6.0 and 7.0 with PYR half-lives of 8.8 and 9.2 days, respectively. The ability of strain PL5 degraded PYR under different temperatures was 35 > 25 > 15 °C at pH 6.0. Among the tested soils contaminated by PYR, the best degradation of PYR by strain PL5 occurred in paddy soil where the degradation was 57.5% after 10 days, and the half-life of PYR was reduced 19-fold in the presence of strain PL5. This study suggested that PL5 could be used for the bioremediation of the contaminated soil and water through the degradation of PYR.