Effect of combination feeding of Nannochloropsis and freshwater Chlorella on the fatty acid composition of rotifer Brachionus plicatilis in a continuous culture
Article first published online: 2 JUN 2008
© 2008 Japanese Society of Fisheries Science
Volume 74, Issue 3, pages 649–656, June 2008
How to Cite
KOBAYASHI, T., NAGASE, T., HINO, A. and TAKEUCHI, T. (2008), Effect of combination feeding of Nannochloropsis and freshwater Chlorella on the fatty acid composition of rotifer Brachionus plicatilis in a continuous culture. Fisheries Science, 74: 649–656. doi: 10.1111/j.1444-2906.2008.01570.x
- Issue published online: 2 JUN 2008
- Article first published online: 2 JUN 2008
- Received 4 June 2007. Accepted 27 December 2007.
- Brachionus plicatilis;
- continuous culture;
- docosapentaenoic acid;
- eicosapentaenoic acid;
- fatty acid composition;
- Nannochloropsis oculata
ABSTRACT: A continuous culture of rotifer was conducted to investigate the effect of combination feeding of both a high density of Nannochloropsis oculata (N) and condensed freshwater Chlorella (FC) on the fatty acid composition of L-type rotifer Brachionus plicatilis in a continuous culture system. The algal feeding of the rotifers was carried out in three successive steps: N-feeding N+FC-feeding FC-feeding. The culture was conducted at 24°C and 25–27 psu in a 2000 mL bottle with 50% of water exchanged daily. The combination N+FC-feeding was effective in increasing rotifer density. The rotifers fed on N+FC (N+FC-R) had more non-polar lipids than polar ones, similar to those on N (N-R), opposite to the rotifers fed on FC (FC-R). N+FC-R contained higher levels of 16:2, 18:2n-6 (linoleic acid [LA]) and 20:2n-6, but lower levels of 18:1, 20:4n-6 (arachidonic acid), 20:5n-3 (eicosapentaenoic acid [EPA]) and 22:5n-3 (docosapentaenoic acid [DPA]) compared with N-R. Whereas N+FC-R contained higher levels of 16:1n-7, EPA and DPA, but lower levels of 16:2 and LA compared with FC-R. N+FC-R had more DPA in polar lipids than in non-polar ones. The Σn-6/Σn-3 ratio in N+FC-R was 0.9–1.0, significantly different from those in N-R (0.4) and FC-R (6.6–8.4). Therefore, it is inferred that the fatty acid profile of the N+FC-R cultured in a continuous culture system was affected by both N and FC. Also, the combination N+FC-feeding may be effective in manipulating the Σn-6/Σn-3 ratio in continuously cultured rotifers.