ABSTRACT
Alginate from brown seaweeds has long been used as a viscosifier, gelling agent, and stabilizer in various applications such as the food, pharmaceutical, and healthcare industries. Alginate oligosaccharides have also attracted some attention from researchers, as these compounds have exhibited various biological activities, such promoting root growth in higher plants, accelerating the growth rate of Bifidobacterium sp., and promoting penicillin production in Penicillium chrysogenum. More recently, an alginate-derived unsaturated monosaccharide, 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEH), has been used as a carbon source for ethanol fermentation with genetically modified microbes. Additionally, 2-keto-3-deoxy-D-gluconate (KDG) and 2-keto-3-deoxy-D-phosphogluconate (KDPG), which are potentially promising lead compounds for novel drugs, have been produced from DEH employing DEH metabolic enzymes from alginolytic bacteria. The efficient production of these alginate-derived materials may now be realized by utilizing alginate lyases and DEH-metabolic enzymes. These enzymes are anticipated to be promising tools for the production of value-added substances from alginate. Thus, in this chapter, we describe the properties of alginate-degrading and -metabolic enzymes from an alginolytic bacterium Flavobacterium sp., strain UMI-01, and a marine gastropod Haliotis discus hannai (abalone) and discuss their potential applications.
