Following an isolation programme for thraustochytrids (marine fungoid protists) from three different locations, 57 isolates were screened for biomass, oil and docosahexaenoic acid production (DHA). Although a common fatty acid profile for the thraustochytrid isolates emerged, there was considerable variation in the DHA content of the oil. In some isolates from a cold temperate environment, DHA represented almost 50% of the total fatty acids present. Although isolates from a sub-tropical environment produced higher levels of biomass, with up to 37% (w/w) oil, the DHA fraction of the fatty acids was low. Cool temperate isolates gave intermediate values. Studies to optimise biomass and DHA production by manipulation of growth medium composition were carried out on a tropical strain. Results indicated that medium with a high C:N ratio stimulated DHA production. The use of such media in bioreactor cultivations gave maximum biomass, lipid and DHA content of 14 g l− 1, 78 and 25% (w/w), respectively. Optimum DHA production was 2.17 g l−1 after 107 h cultivation.
|Title of host publication
|Marine bioprocess engineering, proceedings of an International Symposium organized under auspices of The Working Party on Applied Biocatalysis of the Eurpean Federation of Biotechnology and The European Society for Marine Biotechnology
|R. Osinga, J. Tramper, J. Burgess, R. Wijffels
|Place of Publication
|Number of pages
|Published - 1999
|Progress in industrial microbiology