Pseudomonas monteilii 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 P. monteilii PL5 could be used for the bioremediation of the contaminated soil and water through the degradation of PYR.
Keywords: Microbial degradation; Pseudomonas monteilii; Pyrene; Soil.