2. Methods
2.1. Feedstock
Dried kelp, Laminaria japocia, was purchased from Geumil-do Fisheries Cooperation Association (Wando, South Korea), milled to fine powder, and kept in a sealed container at room temperature until it was used. For the trials, 90 g of the powder was mixed in 3 L tap water to make the concentration 30 g/L and stirred for 6 h at room temperature to maximize mannitol recovery rate in the super- natant (based on results of preliminary work), then left unstirred to allow solids to precipitate.After 24 h, the mixture had separated into
two layers. The supernatant (2 L) was mannitol solution; the bot-tom layer (1 L) was mainly alginate suspension. The supernatant was aspirated off and steam autoclaved at 121°C for 20 min.The alginate suspension was used for VFA production.