It is important to screen strains that can decompose polycyclic aromatic hydrocarbons (PAHs) completely and rapidly with good
adaptability for bioremediation in a local area. A bacterial strain JM2, which uses phenanthrene as its sole carbon source, was isolated
from the active sewage sludge from a chemical plant in Jilin, China and identified as Pseudomonas based on 16S rDNA gene sequence
analysis. Although the optimal growth conditions were determined to be pH 6.0 and 37°C, JM2 showed a broad pH and temperature
profile. At pH 4.5 and 9.3, JM2 could degrade more than 40% of fluorene and phenanthrene (50 mg/L each) within 4 days. In addition,
when the temperature was as low as 4°C, JM2 could degrade up to 24% fluorene and 12% phenanthrene. This showed the potential
for JM2 to be applied in bioremediation over winter or in cold regions. Moreover, a nutrient augmentation study showed that adding
formate into media could promote PAH degradation, while the supplement of salicylate had an inhibitive effect. Furthermore, in a
metabolic pathway study, salicylate, phthalic acid, and 9-fluorenone were detected during the degradation of fluorene or phenanthrene.
In conclusion, Pseudomonas sp. JM2 is a high performance strain in the degradation of fluorene and phenanthrene under extreme pH
and temperature conditions. It might be useful in the bioremediation of PAHs.