Author: Herr Dr. Amoneit
Last saved by: Saritas, Sevim
Company: 宮崎大学

Novel Thraustochytrids Assimilating Pentose for a Microbial Production of Biofuel from the Plant Biomass
Matsuda, A.^1, Taoka, Y.^1, Nagatomo, H.^1, Fujimoto, A.^1, 
Matsuda, T.^2, and Izumi, Y.^2, Hayashi, M.^1
 ^1Department of Marine Biology and Environmental Sciences, Faculty of Agriculture, 
University of Miyazaki, Miyazaki, JAPAN
^2Fukuoka Lab., Biomaterial in Tokyo Co., Ltd., Fukuoka, JAPAN

        For a biofuel production from plant biomass, the novel pentose assimilating oleaginous thraustochytrids were isolated.  In the present study, the carbon source assimilation and the influence of culture conditions on the lipid profile and the growth of the strain were investigated.  
     As isolation sources of the thraustochytrids, dead leaves of mangroves, coastal sea water, sea sand, dead piece of coral, and so on were collected at the coast and the seabed of Hiroshima prefecture and Ishigaki Island in Okinawa prefecture in Japan.  The novel thraustochytrids were isolated from these isolation sources by a pine pollen bating method using the medium containing xylose or arabinose as a sole carbon source.  After appearance of the colonies, the isolates were purified on the same medium.  The fatty acid compositions and contents of the isolates were determined by GLC analysis after methanolysis of their total lipids.  The phylogenic analyses based on the 18S rRNA gene sequences were also carried out for an identification of the isolates.
As a result of screening, the 22 strains of thraustochytrids that could grow on the medium containing 2% of xylose or arabinose as a sole carbon source were isolated from the collected sea water and sea sand.  These strains contained a large amount of fatty acids, such as n-3 docosahexaenoic (DHA) and n-6 docosapentaenoic (DPA) acids in the cells.  All of the strains were identified tentatively as Aurantiochytrium sp. by the phylogenic analysis based on the 18S rRNA gene sequences.  In the present study, the influence of culture conditions, such as concentration of artificial sea water, temperature,pH, and nitrogen source, on the contents and compositions of the fatty acids in the cells and their growth were also investigated.