Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/21/2008
Publication Date: 5/21/2008
Citation: Hou, C.T. 2008. New uses of bioglycerin: Production of arachidonic acid [abstract]. American Oil Chemists' Society. Biol #2.
Technical Abstract: Filamentous fungi of the genus Mortierella are known to produce arachidonic acid from glucose and M. alpina is currently used in industrial scale production of arachidonic acid in Japan. In anticipation of a large excess of co-product bioglycerin from the national biodiesel program, we would like to find a new use for bioglycerin. We screened twelve Mortierella species: M. alpina NRRL 6302, M. claussenii NRRL 2760, M. elongata NRRL 5246, M. epigama NRRL 5512, M. humilis NRRL 6369, M. hygrophila NRRL 2591, M. minutissima NRRL 6462, M. multidivaricata NRRL 6456, M. nantahalensis NRRL 5216, M. parvispora NRRL 2941, M. sepedonioides NRRL 6425, and M. zychae NRRL 2592 for their production of arachidonic acid (AA) and dihomo-'-linolenic acid (DGLA) from glycerol. We used glucose first and found that all of the strains tested produced AA and DGLA. The total fatty acid content of 125 mg/g cell dry weight (CDW) and fatty acid composition for AA (19.63%) and DGLA (5.95%) in the mycelia of M. alpina grown on glucose were comparable with those reported earlier by Takeno et al. (2005). Then we use glycerol as substrate and found that all species tested grew on glycerol and produced AA and DGLA except M. nantahalensis NRRL 5216, which could not grow on glycerol. The amount of AA and DGLA produced are comparable with those obtained with glucose-grown mycelium. The top five AA producers (mg AA/CDW) from glycerol were in the following order: M. parvispora > M. claussenii > M. alpina > M. zychae > M. minutissima. The top five dry mycelia weights productions were: M. zychae > M. epigama > M. hygrophila > M. humilis > M. minutissima, and the top five species for total fatty acids production (mg /g CDW) were: M. claussenii > M. parvispora > M. minutissima > M. hygrophila > M. maltidivaricata. We selected two species, M. alpina and M. zychae for further studies with glycerol as substrate. Their optimum production conditions were determined. Time course studies showed that the maximum cell growth and AA production for both species were at 6 days of incubation. Therefore, glycerol can be considered for industrial use in the production of AA and DGLA.