Long-type ulvan lyase in Alteromonas sp. is a major enzyme involved in degradation of ulvan extracted from Ulva ohnoi

Abstract: Ulvan is one of the key sulfated polysaccharide components constituting the cell walls of green algae, Ulva. A little study has been performed so far on the ulvan degrading bacterial enzymes. In order to utilize ulvan effectively by breaking down to oligosaccharides and monosaccharide, we have studied ulvan-degrading bacterial enzymes. In this study, we firstly isolated a highly ulvan-degrading bacterium, Alteromonas sp. from feces of small marine animals. We identified an ulvan lyase with ca. 55 kDa in size from the secreted proteins of the Alteromonas sp. strain and cloned the gene for it. The predicted molecular weight of the longtype ulvan lyases is 110 kDa. The catalytic domain is located on the N-terminal half and the C-terminus was turned out to be deleted. Although the strain contains two ulvan lyases (long and short, It can be concluded that long ulvan lyase would be the major lyase for ulvan degradation.