Strategy for Sustainable Bio‐Value Chain Development: Algal Biomass Utilization Without Inhibitory Effects on Lactic Acid Production via Efficient Diluted Acid Hydrolysis of Brown Macroalga

ABSTRACT Saccharina japonica, one of the most widely cultivated brown algae species, is considered a promising biorefinery feedstock due to its high carbohydrate content. Dilute acid hydrolysis can be performed to recover sugars from S. japonica; however, the impact of sugar derivatives (potential inhibitors) generated during the hydrolysis process on lactic acid production remains unexplored. In this study, the inhibitory effects of sugar derivatives on the fermentation performance of Lacticaseibacillus rhamnosus were systematically examined to enhance the bioconversion efficiency of S. japonica. Firstly, the sugar derivatives present in S. japonica hydrolysate were identified, revealing the presence of acetic acid, formic acid, and furfural. Subsequently, their inhibitory effects on lactic acid production were assessed, demonstrating significant inhibition (p < 0.05) at the following c…