Biochemical Composition and Food Value for Rotifers of the Marine Microalga Tetraselmis tetrathele Grown in Glucose Medium

Abstract

Six strains of Tetraselmis, comprising T. tetrathele, T. chui, T. alacris, T. gracilis, T. suecica Spain, and T. suecica Brasil, were cultured in seawater (salinity, 27%o) supplemented with 80 mg of ammonium sulfate, 16 mg of calcium perphosphate and 4 mg of Clewat-32 per liter, with or without 100 mM glucose, under 14 h illumination (3, 000 lx) per day. All the strains except T. alacris grew better in the medium containing glucose. In particular, the growth of T. tetrathele and T. chui was accelerated by the addition of glucose, the rates being 1.42 and 1.40 doublings per day, respectively, at the logarithmic phase. When cultured in the dark, their growth rates ranged between 0.94 and 0.90 doublings per day in the presence of glucose. An appropriate condition for the mixotrophic culture of T. tetrathele was considered to be as follows: 100 mM glucose, 0.6 mM ammonium sulfate, 10 h/day illumination, and 30°C. Under this condition the protein, carbohydrate, lipid, and fatty acid contents of this alga were 31, 11, 13, and 4.5%/cell dry-weight, respectively. Furthermore, the growth of rotifers was enhanced by feeding cells of glucose-grown T. tetrathele. © 1998, The Japanese Society of Fisheries Science. All rights reserved.