Marine macroalgae, Ceylon moss containing low lignin and high levels of fermentable sugar (42%), was tested as a potential fermentation feedstock for solventogenic clostridia (Clostridium tetanomorphum ATCC49273, Clostridium acetobutylicum ATCC824, Clostridium aurantibutyricum NCIMB10659, and Clostridium beijerinckii NCIMB8052). As a major carbohydrate of pretreated Ceylon moss (hydrolyzate of Ceylon moss, hCM; hydrolyzate of Agar, hA) is a galactose, four strains were tested to verify galactose availability: C. tetanomorphum was screened out, because it could not utilize galactose. The other strains were then cultivated with hCM or hA. As a result, C. acetobutylicum and C. aurantibutyricum showed bacterial growth with consumption of galactose in both hCM and hA, whereas C. beijerinckii did not grow on hA, possibly due to susceptibility to inhibitor(s) existed. Fatty acids and solvents were produced; substantiating the fact that Ceylon moss can be used as a biomass resource for biochemicals production. (C) 2013 Elsevier Ltd. All rights reserved.