| abstract |
Provided is a medium component for culturing microorganisms or microalgae more efficiently. A nutritional additive for culturing microorganisms or microalgae is produced by culturing microalgae in a medium, producing a biomass derived from the microalgae in the medium, and adding an acid to the biomass in order to hydrolyze the biomass and prepare a hydrolysis product of a biomass as a nutritional additive. |