l-Fucose Synthesis Using a Halo- and Thermophilic l-Fucose Isomerase from Polyextremophilic Halothermothrix orenii

Abstract

l-Fucose isomerase (l-FucI)-mediated isomerization is a promising biotechnological approach for synthesizing various rare sugars of industrial significance, including l-fucose. Extremozymes that can retain their functional conformation under extreme conditions, such as high temperature and salinity, offer favorable applications in bioprocesses that accompany harsh conditions. To date, only one thermophilic l-FucI has been characterized for l-fucose synthesis. Here, we report l-FucI from Halothermothrix orenii (HoFucI) which exhibits both halophilic and thermophilic properties. When evaluated under various biochemical conditions, HoFucI exhibited optimal activities at 50-60 degrees C and pH 7 with 0.5-1 M NaCl in the presence of 1 mM Mn2+ as a cofactor. The results obtained here show a unique feature of HoFucI as a polyextremozyme, which facilitates the biotechnological production of l-fucose using this enzyme.