Marine algae microalgae

In addition to applications as direct and indirect feeds mentioned above, the heterotrophic production of microalgae can potentially provide a cost-effective source of nutrient components, e.g. marine protein, PUFA or astaxanthin, that can be incorporated into formulated feeds for larval stages and beyond. Harel and Place (2004) provide more detail on the broad applications of heterotrophic production of marine algae for aquaculture. 

Marine microalgae have also been used for the stereoselective reduction of a- and P-keto esters to the corresponding hydroxy esters [30]. The marine algae were photoautotrophically cultivated in synthetic seawater at 20 °C under constant aeration and illumination by white fluorescent light. In particular, Nannochloropsis sp. catalyzed the reduction of ethyl 2-methyl-3-oxobutanoate 20 to the anti-hydroxy ester (2S,3S)-20b with high conversion, excellent diastereoselectivity syn/anti = 1 99), and high enantioselectivity (anti >99%, syn 98%) (Scheme 12.14). 

Sims JJ, Lin GHY, Wing RM (1974) Marine natural products. X. Elatol, a halogenated sesquiterpene alcohol from the red alga Laurencia elata. Tetrahedron Lett 39 3487-3490 Singh S, Kate BN, Banerjee UC (2005) Bioactive compounds from cyanobacteria and microalgae an overview. Crit Rev Biotechnol 25 73-95... 

The haptophyte microalga Emiliania huxleyi produces biomarkers in the form of long-chain (C37, C38, and C39) alkenones (Brassell, 1993). Alkenones are well preserved in marine sediments and their molecular distributions and isotopic composition have been used to infer paleo-temperatures (Brassell, 1993) and pC022 values (Jasper et ak, 1994), respectively. Unsaturation patterns in the alkenone series are related to the growth temperature of the haptophyte algae that produce these compounds (Brassell et ak, 1986 Prahl and Wakeham, 1987), and hold great promise as indicators of absolute ocean paleotemperature. 

---