Volatile fatty acids production from marine macroalgae by anaerobic fermentation

► Volatile fatty acids (VFAs) were produced from macroalgae by anaerobic fermentation with a mixed culture. ► The highest VFAs product concentration of 15.2 g/L was obtained from 50.0 g/L of alkaline pretreated Laminaria japonica in three days of anaerobic fermentation. ► The VFA productivity varied with different types of macroalgae, probably depending on the type of polysaccharides in the macroalgae. ► VFAs productivity was enhanced up to 56% by the alkaline pretreatment.