The biotechnological potential of thraustochytrids

Thraustochytrids are common marine microheterotrophs, taxonomically aligned with heterokont algae. Recent studies have shown that some thraustochytrid strains can be cultured to produce high biomass, containing substantial am ounts of lipid rich in polyunsaturated fatty acid (PUFA). It is also eviden t that cell yield and PUFA production by some thraustochytrid strains can b e varied by manipulation of physical and chemical parameters of the culture . At present, fish oils and cultured phototrophic microalgae are the main c ommercial sources of PUFA. The possible decline of commercial fish stocks a nd the relatively complex technology required to commercially produce micro algae have prompted research into possible alternative sources of PUFA. The culture of thraustochytrids and other PUFA-producing microheterotrophs is seen as one such alternative. Indeed, several thraustochytrid-based product s are already on the market, and research into further applications is cont inuing. Many fish and microalgal oils currently available have relatively c omplex PUFA profiles, increasing the cost of preparation of high-purity PUF A oils. In contrast, some of the thraustochytrids examined to date have sim pler PUFA profiles. If these or other strains can be grown in sufficient qu antities and at an appropriate cost, the use of thraustochytrid-derived ail s may decrease the high expense currently involved with producing high-puri ty microbial oils. As more is learned about the health and nutritional bene fits of PUFA, demand for PUFA-rich products is expected to increase. Result s to date suggest that thraustochytrids could form an important part in the supply of such products.