Abstract: Transglutaminase (EC2.3.2.13, TGase) is an important food enzyme. Since the N-terminal pro-region of TGase has great effect on its folding, TGase is often expressed as its non-active form (pro-TGase) in heterologous hosts. In this study, Streptomyces mobaraensis pro-TGase was used as the gene source and Yarrowia lipolytica po1h was selected as host. By inserting the Kex2 protease recognition site in pro-TGase (strategy 1) and co-expressing pro-TGase and transglutaminase activating metalloprotease (TAMEP) (strategy 2), pro-TGase was expressed in Y. lipolytica at first, then the pro-region of pro-TGase was excised and the mature TGase was achieved. The results of shake flask fermentation showed that the TGase activities of recombinant strains constructed by strategy 1 and strategy 2 were 5.26 U / mL and 6.77 U / mL, respectively. Moreover, the enzymatic properties were further studied. The results showed that the specific activities, Km and kcat/Km of the recombinant TGase obtained by strategy 1 and strategy 2 were significantly higher than those of S. mobaraensis TGase. Based on the food safety of Y. lipolytica, the results provide two new high-yield strains for the industrial production of TGase.

Key words: transglutaminase, Yarrowia lipolytica, activity expression, protease recognition site, activating protease