Abstract
Biorefinery is a coined word defined as the technology for manufacturing biofuels and chemical products using biomass as a raw material. We are vigorously conducting research on marine biorefinery using the Japanese Lessoniaceae (Eisenia bicyclis, Eisenia arborea, Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera) as biomass. In this review, we introduce the latest research results in the following three areas: (1) phlorotannins and their new physiological functions, (2) separation and application of seaweed-degrading bacteria, and (3) production of rare sugar from alginic acid. Phlorotannins, which are specifically contained in brown algae, are attracting attention as new functional polyphenols. As a new physiological function, it was found that phlorotannins (eckol and its oligomers) contained in the Lessoniaceae have anti-glycation activity superior to aminoguanidine, a synthetic anti-glycation agent. A marine bacterium Formosa haliotis strain MA1, which was newly isolated from the gut of abalone, has many hydrocarbon degradation genes to degrade brown algal polysaccharides. Alginic acid is the mucus polysaccharide most abundantly contained in brown algae. It was also revealed that the strain MA1 has the ability to produce succinic acid from alginic acid. Furthermore, a marine bacterium Falsirhodobacter sp. alg1 has two novel alginate lyases (AlyFRA and AlyFRB) that have been isolated from spoilage of the brown algae. We succeeded in producing the rare sugar (4-deoxy-L-erythro-5-hexoseulose uronic acid) from alginic acid with high purity and high yield using recombinant proteins of the alginate lyases.
In September 2016, we established the Seaweed Biorefinery Research Center at Mie University in order to globally disseminate our research results and products.
