A novel alpha-L-rhamnosidase with potential applications in citrus juice industry and winemaking

ALVARENGA A.E.; ROMERO C.M.; CASTRO, G.R.

EUROPEAN FOOD RESEARCH AND TECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2013

1438-2377

The production of monoglycosylated flavonoids by α-L-rhamnosidases (EC 3.2.1.40) is an interesting development in biocatalysis. Applications of rhamnosidases in industry include removal of bitterness caused by naringin from citrus juices. In the present work a psychrotolerant bacterial strain with α-L-rhamnosidase activity was isolated. The α-L-rhamnosidase was found to be able to degrade naringin and was purified and characterized. The α-L-rhamnosidase from Brevundimonas sp. Ci19 was able to release both rhamnose and prunine from naringin. The enzyme was partially purified with a performance of 2.7-fold purification. The α-L-rhamnosidase showed an optimum pH between 6.00 and 7.00 with substantial residual activity at pH 5.00 (85.3%). The optimum temperature was between 20 and 37 ºC. The enzyme showed activation in the presence of Ca2+ and Cd2+ ions and at a high ethanol concentration level (10% v/v). Activity was found for β-D-glucosidase (EC 3.2.1.21) in the partially purified extract, but it was inactive in the acid pH region. This result indicates the potential for inactivation of β-D-glucosidase along with the high level of α-L-rhamnosidase activity necessary for production of flavonoid glycosides. The α-L-rhamnosidase from Brevundimonas sp. Ci19 showed interesting properties not only for potential use in the citrus juice industry and in winemaking.