Transformation of remnant algal biomass to 5-HMF and levulinic acid: influence of a biphasic solvent system.

The primary commercial product from the green microalgae is β-carotene. After extracting the lipophilic fraction containing this red-orange pigment, an algal residue remains. As the carotenogenesis is induced by light stress with simultaneous nitrogen depletion, the protein content is low and the remnant is comprised largely of storage carbohydrates.