Structure of microbial community that sustain subtropical dry land and coral reef ecosystems in Australia.

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Northeast Australia and Okinawa share subtropical environments that exhibit remarkable biodiversity. There are many unique biotas not only in land area but also n coastal area of those regions. Interestingly, Northeast Australia and Okinawa also share a considerable number of species in spite of the geographic distance. Thus, it is of particular interest to compare Northeast Australia and Okinawa to find a fundamental basis that sustain the unique ecosystems. Recent investigations have suggested that microbial community plays essential roles in sustaining ecosystems and biosphere. This research project aimed to obtain basic information on characteristics of microbial community in Australia and Okinawa. We highlighted two microbial community for the two-yeas project: intestinal bacteria in termites (FY 2005) and endolithic bacteria in reef-building corals (FY 2006) as representative terrestrial and coastal microbial community, respectively.For the source of terrestrial microbial communi … More ty, we collected termites distributed in Australia and attempted to investigate their intestinal microbes and microbial endosymbionts. We have found that the intestinal fauna of the most primitive termite Mastotermes danviniensis play a significant role in cellulose digestion as other termite species including those collected in Okinawa. Comparative analysis between Okinawan and Australian Nasutitermes termites revealed that the intestinal bacteria also produce a variety of cellulolytic enzymes unlike previously suggested. We have successfully parified the bacterial endosymbiont Blattabacterium cuenoti (Bacteriodetes, Flavobacteria) and have estimated the genome size to be 650 kb. The results suggest reduction in genome compared to free-living relatives, and that such reduction is typical in intracellular proteobacterial sympointsFor the source of coastal microbial community, we colleted the colonies of Goniastrea aspera, a reef-building corals from Queensland. Through collaboration with Dr. Andrew Baird of James Cook University, we have successfully collected 20 coral colonies from Nelly Bay of Magnetic Island and Pioneer Bay of Orpheus Island. We analyzed water quality on site to estimate nitrate, nitrite, ammonium ions as well as pH and salinity. The samples collected were processed to extract DNA from each coral skeleton. The analysis of the data is now under going. Less