Carrageenan is a natural carbohydrate obtained from red seaweed of carrageenanophytes. It is formed by alternate units of D-galactose and 3,6-anhydro-D-galactose, with ester-sulfate groups in different position of saccharide units. Bio-refinery technologies are very useful to control the degradation and get exactly the carrageenan oligosaccharide structure that you want.
The enzyme used for biodegradation is called carrageenase. In our research, one marine bacterium which can degrade carrageenan has been isolated and identified as Zobellia galactanivorans. The cloning and sequencing of the κ-carrageenase gene, and the expression of the recombinant κ-carrageenase were carried out both in E. coli and Pichia pastoris. The recombinant enzyme was used to comprehensive utilize the seaweed of Kappaphycus, and the potential application of three products were carried out. The carrageenan sulfatase has high desulfurization rate which can remove the sulfate from the molecules and form the anhydro-bond. Researches were carried out to develop different sulfatases with substrate specificity.
Carrageenophytes are abundant in tropical area. By development of biorefinery technology, we can obtain various kinds of carrageenan product that can be used in feed, functional food, cosmetics, and pharmaceuticals, and thus greatly improve the economic value of Carrageenophytes.