A process for preparing an algal powder containing a reduced content of proteins, a bioplastic composition formed from such a powder, a process for manufacturing a plastic product obtained from such an algal powder and also the plastic product obtained in this way. Process for preparing an algal powder, especially intended for the manufacture of a plastic product, including the successive steps of: culturing and/or harvesting an algal biomass; reducing by at least 10% the intrinsic amount of proteins of the algae, by weight relative to the weight of proteins of the harvested biomass; drying; and reducing to give powder or granules.

A process for preparing an algal powder containing a reduced content of proteins, a bioplastic composition formed from such a powder, a process for manufacturing a plastic product obtained from such an algal powder and also the plastic product obtained in this way. Process for preparing an algal powder, especially intended for the manufacture of a plastic product, including the successive steps of: culturing and/or harvesting an algal biomass; reducing by at least 10% the intrinsic amount of proteins of the algae, by weight relative to the weight of proteins of the harvested biomass; drying; and reducing to give powder or granules.