Vibrio species degrade the D-GlcNAc-b-1,4-D-GlcNAc linkage found in chitin by secreting hydrolases that form GlcNAc and chitinbiose,where the former is then imported into the cell and the latter is degraded by hydrolysis or by phosphorolysis to release D-GlcNAc-1-P.103 The N,N0-diacetylchitobiose phosphorylase involved in this process has been found to transfer D-GlcNAc from D-GlcNAc-1-P onto D-GlcNAc and p-nitrophenyl and methylumbelliferyl b-glycosides of D-GlcNAc.