n a former railway repair shop in the southern French city of Arles, flasks of lurid green algae are bubbling away, in a room that looks like a cross between a laboratory and a witch’s potion-brewing den. Nearby, a 3D printer spews out objects made from algae-based bioplastic and algae-dyed textiles hang on a rack. Some of the walls appear to be made of rice cakes, others look like Weetabix, while some are daubed with a coat of porridgy
