Fed-batch production of ice-binding protein of Flavobacterium frigoris PS1 by recombinant Pichia pastoris

Abstract

Ice-binding proteins (IBPs) inhibit ice growth to permit the survival of polar organisms in the cold environments. The recombinant IBP from an Antarctic bacterium, Flavobacterium frigoris PS1, FfIBP (Flavobacterium frigoris ice-binding protein), was produced using Pichia pastoris expression system. The optimum fermentation temperature and pH for fed-batch production of FfIBP were 30℃ and 5, respectively. The maximal cell density and purified FfIBP were 112 g/L and 70 mg/L, respectively. The thermal hysteresis (TH) activity (0.85℃) of FfIBP obtained using a glycerol-methanol fed-batch culture system was 2-fold higher than that of the LeIBP (Leucosporidium ice-binding protein). This work allows for large-scale production of FfIBP, which could be extended to further application studies using recombinant IBPs.