DEVELOPMENT OF AN INDUSTRIAL-SCALE PROCESS FOR THE HETEROTROPHIC PRODUCTION OF A MICROALGAL MOLLUSK FEED

Micro-algae are widely used as a traditional feed for the early developmental stages of molluscs and crustaceans. A large spectrum of algae are cultivated; these have been selected because they have a suitable chemical and nutritional profile, are of the correct size and grow well photoautotrophically. A large number of potential feed organisms have been screened for their nutritional suitability and growth characteristics, with the above criteria expanded to include the capacity for heterotrophic growth. A process for the heterotrophic cultivation of Tetraselmis suecica CSL161, has been developed and scaled up to an industrial-level process. The biomass produced, after concentration, is stabilized by drying to give a free-flowing powder. Growth trials with the bivalves Crassostrea gigas, Crassostrea virginica, Tapes philippinarum, Mercenaria mercenaria and Ostrea edulis have demonstrated that dried Tetraselmis CSL161, sold as Celsys Algal 161, can directly replace live Tetraselmis in bivalve feed and may provide up to 70% replacement for hatchery-grown micro-algae.