TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Microorganism: (I) uses one or more PAHs as sole carbon and energy source.Preferred Composition: (III) is in the form of a spray, foam, liquid or in lyophilized form. SPECIFIC MICROORGANISMS - (I) is chosen from Penicillium janthinellum VUO 10201, Stenotrophomonas maltophilia VUN 10010, 10012, Bacterial consortium VUN 10009, Pseudomonas fluorescens VUN10011 or Burkholderia sp. VUN 10013, having Accession numbers. NM98/09532, NM98/09528, NM98/09530, NM98/09527, NM98/09529 and NM98/09531, respectively (claimed).    EXAMPLE - Polycyclic aromatic hydrocarbon (PAH)-degrading microorganisms were isolated from PAH-contaminated soil samples. Enrichment and isolation of PAH-degrading bacteria was carried out using pyrene as a sole carbon and energy source. A bacterial consortium was enriched in a 100 ml volume of Ringer's solution, 5 ml of the supernatant was used to inoculate a 45 ml volume of basal salt medium (BSM) containing 100 mg/l pyrene. When microbial growth was visible, a portion of culture broth was transferred to fresh pyrene-containing BSM. After several subcultures, pure cultures were isolated. Gram staining and biochemical tests for bacterial identification were performed. Isolates were tested for their ability to grow on various pyrene concentrations, on different PAHs and 25 other carbon sources. Starter cultures were grown in BSM-pyrene at 30 degrees C and 175 revolutions per minute (rpm) for 7 days. The cells were collected and washed in BSM and the resuspended cells were inoculated into BSM containing different carbon sources. Three distinct isolates each of which was slightly different in colony shape and color were selected. These three gram-negative strains were identified as members of genus Pseudomonas and were designated strains VUN10010, VUN10011 and VUN10012. Strains VUN10010 and VUN10012 showed 90-100 % sequence homology to Stenotrophomonas maltophilia. In a second experiment, enrichment of PAH-degrading microorganisms was performed using benzo(a)pyrene as a sole source of carbon and energy. A mixed microbial population was obtained from creosote-contaminated soil enriched with benzo(a)pyrene. A pure fungal isolate, identified as Penicillium janthinellum on the basis of macroscopic and microscopic characteristics, was obtained from this enriched culture. This fungus was assigned the Victoria University of Technology culture collection number of VUN 10201. By inhibiting fungal growth, a consortium of bacteria was isolated on pyrene. This bacterial population was designated as VUN 10009. A pyrene-degrading pure culture was isolated from bacterial consortium VUN10009 and this was assigned the number VUN10013. PAH degradation of co-cultures and axenic cultures of strains VUO10201, VUN10010, and the bacterial consortium were tested in uncontaminated soil spiked with PAH mixture consisting of 3-7 benzene ring compounds. Bacteria were inoculated into the soil to give an initial bacterial population of 10 to the power 7 cells/g soil. At designated time intervals, samples of 1 g of soil were collected for analysis of PAH concentration. The fate of pyrene, chrysene, benz(a)anthracene, benzo(a)pyrene and dibenz(a)anthracene in PAH-spiked soil was monitored over 100 days. The results showed that pyrene was rapidly degraded in soil inoculated with either S. maltophilia VUN 10010 or the bacterial consortium with all the pyrene (250 mg/kg soil) being degraded in 16-18 days. The degradation rate of the compounds was slow in soil inoculated with only the bacterial consortium or with VUN 10010. The amount of these PAHs degraded over 100 days was in the range of 16-32 % for VUN 10010 and 12-22 % for the bacterial consortium. There was no detectable degradation lag period in soils inoculated with P. janthinellum VUO 10201 and the PAH degradation rate was high in the first 30-40 days compared to soils inoculated with only the bacteria. The amount of the compounds degraded by VUO 10201 after 100 days was in the range of 24-48 %.