Xylosidase involved in ulvan degradation (Ref.2, PubMed:31285597). Ulvan is the main polysaccharide component of the Ulvales (green seaweed) cell wall. It is composed of disaccharide building blocks comprising 3-sulfated rhamnose (Rha3S) linked to D-glucuronic acid (GlcA), L-iduronic acid (IduA), or D-xylose (Xyl) (Probable). Beta-xylosidase converts Xyl-Rha3S, a product of alpha-L-rhamnosidase acting on Rha-Xyl-Rha3S oligosaccharides, further to Xyl and Rha3S (PubMed:31285597). The enzyme is able to degrade 4-methylumbelliferyl-beta-D-xylopyranoside (MUX) in vitro (Ref.2). By ulvan and rhamnose. Belongs to the glycosyl hydrolase 3 family.