Aquaculture & Fisheries

Biography

Biography: Yousuke Taoka

Abstract

World aquaculture production has continued to increase. Fishmeal is used as protein sources for aqua-feeds. However, the price is drastically increased to around 170,000/ ton in 2013 during recent 10 years because of the decrease of fish resources, anchovy. This is serious problem for sustainable aquaculture. Therefore replacement of fishmeal to another resource is urgently needed. Thraustochytrids are widely distributed in marine environment and can ccumulate large amount of lipids in cell bodies. Therefore, thraustochytrids have attracted strong interests for production of valuable lipids. In the process of lipid extraction from the cultured cells, extract residue are produced as byproducts. It is considered that this extract residue except for lipids is mainly consists of protein. From the viewpoints of industrial application of thrautochytrid cells as protein sources, we have planned to apply this byproducts as protein resources instead of fishmeal for aquafeeds. In this study, we evaluated the amino acid profile of thraustochytirds as auafeeds. In the case of a thraustochytrid, Aurantiochytrium limacinum mh0186, the content of crude protein and lipid per g of the cultured cell were 333 mg and 440 mg, respectively. The amino acid of the cultured cells are mainly consisted of around 20 kinds including essential amino acid such as glycine, leucine, isoleucine, glutamate and arginine. At present, we have isolated more than one hundred thraustochytrids from marine enviroment and are making the amino acid profile. We are searching the adequite thraustochytrid strains as protein source in the field of aquaculture.