The carbohydrate profile of the untreated microalga N. gaditana, determined by HPLC analysis after analytical acid hydrolysis, consists mostly of glucose, xylose and rhamnose (and other unidentified sugars present in a small amount) with a total sugar content of 13.5%. This result is in agreement with the carbohydrate analyses performed by other researchers on similar microalgae species [12,26,28].