Rhamnose is a deoxy sugar and got its name from the plant Buckthorn (Latin: Rhamnus) where it was isolated. The L-Rhamnose is the naturally predominant sugar form. In nature the rhamnose can be found, additionally to Buckthorn in poison Sumac, plants of the genus Uncaria and in microalgae belonging to class Bacillariophyceae (diatoms).In nature rhamnose is often found linked to other sugars. It is a common component of glycosides from many plants and found in the peptidoglycan of the cell wall of acid-fast bacteria in the Mycobacterium genus.
Rhamnose can also be fermented by several microorganisms like E. coli, Enterobacter, Citrobacter, Klebsiella and some species of Salmonella. Acid production from rhamnose is a characteristic phenotype of Listeria monocytogenes. Therefore, rhamnose can be used for differentiation and identification of bacteria, it is used in media like Rhamnose broth or Phenol red Rhamnose broth.