Abstract: Fossil energy shortages and escalating environmental issues have spurred interest in marine biomass as a renewable and economically viable resource for bioenergy and green chemical production. Brown algae, characterized by their unique chemical composition of alginate, mannitol, and fucoidan, have emerged as critical feedstocks for high value-added applications. Physical, chemical, biological, and combined pretreatment methods can further enhance the decomposition efficiency. We systematically summarize advancements in brown algal fermentation for high value-added product production. Brown algae can efficiently synthesize biofuels (hydrogen, ethanol, and butanol) through dark fermentation, combined with strain screening and genetic engineering. Additionally, optimizing microbial selection, fermentation conditions (pH, temperature, substrate concentration), and incorporating additives such as nanoscale zero-valent iron (nZVI) can enhance the activities of key enzymes (hydrogenase and alcohol dehydrogenase), thereby improving product yield and energy conversion efficiency. We further identify the key factors restricting the industrial application of brown algae fermentation and propose future research directions.

Key words: brown seaweed biomass, fermentation, high value-added product, pretreatment, process optimization