Production of bioactive oligopeptide hydrolyzed by protease derived from aerial microalga Vischeria helvetica.

This study focused on a culture system of aerial microalgae with the decomposition of casein protein for obtaining bioactive compounds such as peptides with inhibitory activity against angiotensin-converting enzyme (ACE). The aerial microalga Vischeria helvetica exhibited growth in Bold's basal medium supplemented with casein protein as nitrogen source. The algal cells secreted protease and amino oxidase into the medium, and ammonium ions as a nitrogen source was produced by the conjugated-enzyme reaction. Furthermore, a bioactive peptide with ACE-inhibitory activity was efficiently produced from casein protein by the proteases secreted under light conditions. The results presented will facilitate the development of production systems for useful materials from photosynthetic microorganisms and casein protein in a culture medium.