4-Nitrophenyl ?-L-arabinofuranoside has been used: as a substrate for ?-arabinofuranosidase in an enzymatic assay to determine glycosidase activities in Oenococcus oeni strainsto determine the enzymatic activity of ?-arabinofuranosidaseas a p-nitrophenol linked substrate to determine its activity in Aspergillus nigerNW249 culture filtrate