Comparison of distribution of oil-degrading filamentous fungi on subtropical Iriomote Island, Japan, and tropical Con Dao Island, Vietnam

Oil-degrading filamentous fungi (ODF) were enumerated and isolated from two islands, Iriomote, Japan, and Con Dao, Vietnam. Iriomote has a subtropical and Con Dao a tropical climate. The counts of total fungi and ODF in sediment samples from supratidal and intertidal zones on Iriomote were statistically higher than on Con Dao. Water samples from seawater, however, gave a reverse result. In total, 23 ODF including 11 isolates in 5 genera from Iriomote and 12 isolates in 4 genera from Con Dao were isolated. On Iriomote, the isolates which showed the highest potential of oil degradation were 2 Penicillium isolates and one Trichoderma, however they did not grow at 37°C nor survived at 37°C. One Candida isolate has higher potential of oil-degradation, and grew and survived at temperature 42°C. On the contrary, on Con Dao, 2 Aspergillus, one Penicillium and one Trichoderma isolates had potential of oil-degradation, and grew and survived at temperature 42°C. This result suggests that comparing with subtropical Iriomote, the tropical Con Dao maintains more oil-degrading fungi which have higher-temperature resistance.