Growth of <i>Astasia longa</i> on Ethanol. I. Effects of Ethanol on Generation Time, Population Density and Biochemical Profile

Abstract

SYNOPSIS. The colorless flagellate, Astasia longa , grows to high cell densities (5–6.6 × 10 6 cells/ml) with ethanol instead of acetate as carbon source in a chemically defined medium. The generation time was the same on the two substrates. The dry weight of ethanol‐grown Astasia was 23% higher than acetate‐grown Astasia , largely due to a higher carbohydrate content which offset a reduced lipid content. Protein, RNA, and DNA contents were comparable in the two cases whereas O 2 uptake was 17% higher in the ethanol‐grown Astasia. The high population densities on ethanol are examined in terms of these biochemical differences as well as changes in the medium during growth.