Galactose-based biohydrogen production from seaweed biomass by novel strain Clostridium sp. JH03 from anaerobic digester sludge

Seaweed biomass in Korea is rich in galactose following hydrolysis, and leveraging this resource for enhancing the biohydrogen production is the aim of this study. The study investigates the biohydrogen production potential of a newly isolated pure strain, Clostridium sp. JH03, utilizing galactose and seaweed biomass as renewable feedstocks. The strain could utilize galactose as the sole carbon source for biohydrogen production, with a maximum hydrogen yield of 1.61 mol H 2 /mol galactose. The parameters included pH, temperature, and initial galactose concentration, which were varied to determine the optimal conditions for maximum biohydrogen production. The optimal conditions for biohydrogen production were pH 9 and a temperature of 25 °C, with an initial galactose concentration of 10 g/L. Moreover, hydrogen production from seaweed hydrolysate by Clostridium sp. JH03 resulted in maximum production of 1.71 mol H 2 /mol galactose. The study also investigated that combining sludge, a common practice in dark fermentation, with JH03 increased biohydrogen production by up to 34%. By addressing the need for clean energy and reducing raw materials price using biomass, this study contributes to the advancement of sustainable and cost-compatible energy solutions.