a-L-rhamnosidases (E.C. 3.2.1.40) are found widely distributed
in nature and have been reported in animals,
plants, yeast, fungi and bacteria, where they are responsible
for the cleavage of a-L-rhamnose from a wide range of
compounds.1 a-L-rhamnose is found in plants and bacteria
as components of polysaccharides, such as pectins,2 and
the O antigen polysaccharides, responsible for determining
the antigenicity of pathogenic bacteria3; it is also found in
rhamnolipids4 and it is attached to small molecule natural
products, such as rutin. There is industrial interest in arhamnosidases
for use in the debittering of citrus juices
and for the release of flavonoids from rhamnosylated precursors;
in wine production they play a role in the hydrolysis
of glycosylated terpene aroma compounds.
