Low hydrolysis yields (2.6-11.7%) were observed in alkali and hydrothermal pretreatment of macroalgae, although seawater led to relatively higher yields.  SEM images of hydrolyzed macroalgae showed that reverse-osmosis water caused contortions in the remaining cell walls following acid and hydrothermal pre-treatments in the L. digitata and U. linza samples. 
THERM