Codon Optimization and Expression of Cyclodextrin Glycosyltransferase from Gebacillius sp. CHB1 in Pichia pastoris

Abstract:

To achieve high-level expression of cyclodextrin glycosyltransferase from Gebacillius sp.CHB1 in methylotrophic yeast Pichia pastoris GS115，the DNA sequence（CGT1） encoding 680 aminno acids was amplified. The CGT2 was synthesized based on the codon preference of Pichia pastoris. Then CGT1 and CGT2 were respectively fused to the pPICZαA and expressed in Pichia pastoris. Two strains （GS115/pPICZαA-CGT1and GS115/pPICZαA-CGT2）were abtained. After methanol induction for 120 h in a shake flask ，the enzyme activity of CGT2 reached 0.62 U/mL，1.7 times higher than CGT1（0.37 U/mL）. Shake flask experiments were conducted to optimize the fermentation conditions. Highest enzyme activity achieved to 1.26 U/mL by induction for 120 h under the optimal conditions.（pH 6.5，28℃，200 r/min，inoculation amount of 1.5% methanol），two times higher than before.