Acetone-butanol fermentation of marine macroalgae

► Brown macroalgae contain high concentrations of mannitol and laminarin. ► Clostridium acetobutylicum ferments these seaweed extract substrates to butanol. ► Seaweed fermentation exhibited triauxic growth: glucose-mannitol-laminarin. ► Butanol yields in seaweed and pure glucose fermentations were comparable.