Chrysene is a class of organic compounds, arranged in four benzene rings, and a polycyclic aromatic hydrocarbon (PAH), It has been found to have a variety of toxicity, mutagenicity, teratogenicity, and carcinogenicity on microorganisms, plants and animals in environment. Nowadays, the most attention on degradation of PAHs is investigating degradation of high-molecular-weight molecules. However, microbes which have ability to degrade PAHs containing more than three benzene rings are more difficult to be obtained. In order to provide chrysene degrading fungi, this study was conducted for screening, and isolating the fungi from soil, and hence investigating the selected fungi having high chrysene degradation activity. From the 62 soil samples collected from Matsuyama-Japan, 92 isolates were found and 20 isolates of them grew well in Malt extract media contaminated with chrysene (covered up 90%). Among them, a fungus, Fusarium sp. has the highest activity to degrade chrysene compared to others screened fungi. This fungus was evaluated further on liquid medium from distilled water and sea water to confirm their validity in degrading chrysene. The result showed that Fusarium sp. F092 degraded 48% of chrysene, where the chrysene degradation showed no differences at salinity of 35o/oo. The effect of variation of enzymes activities on incubation times was evaluated simultaneously. When the fungus was grown in a liquid culture, the highest activity of 1,2-dioxygenase reached 203.5 UL-1 were observed on 30 days incubation and 29.7 Ul-1 for 2,3-dioxygenase on 40 days incubation. The products of chrysene degradation by Fusarium sp. F092 are, 1-hydroxy 2-napthoic acid and catechol. In conclusion, Fusarium sp. F092 shows a high potential activity degrade PAHs contamination .
Keywords: Screening, chrysene, bioegradation, Fusarium sp. F092