Isolation and some properties of bacteria that degrade polycyclic aromatic hydrocarbons

Four bacteria, which could grow on pyrene as the sole source of carbon, were isolated from soil from an urban area in Tokyo. One of them, strain H2-5, was a rod bacterium that was positive in gram staining and in acid-fast staining. The optimum growth temperature was 34-35 degrees C, and the upper limit temperature for the growth was around 45 degrees C. At a concentration of 1.3 mu g/ml polycyclic aromatic hydrocarbon (PAH), H2-5 cells (45 mu g dry weight/ml) grown on Tryptic Soy Broth made disappear 90% of pyrene in 12 hr, and Benzo(a)pyrene (BaP), Benz(a)anthracene (BaA), and Benzo(ghi)perylene individually disappeared 60%, 25%, and 8%, respectively, in 3 days. PAHs in the extract by dichloromethane from airborne particles in approximately 5 m(3) of air disappeared by the action of H2-5 as follows: pyrene, 100% in 3 days; BaA and BaP, 70% and 71%, respectively, in 4 days. Pyrene in tarry matter extracted from soil disappeared 88% in 4 days.