Cold active transglutaminase from antarctic Penicillium chrysogenum: Partial purification, characterization and potential application in food technology

Abstract

A novel transglutaminase (TGase, EC 2.3.2.13) from antarctic Penicillium chrysogenum was partially purified using ammonium sulfate precipitation and anionic exchange chromatography. The final extract had a specific activity of 7.81 mU/mg, purification fold of 7.16, and a yield of 5.02%. The molecular weight was estimated to be 67 kDa by bioinformatic analysis and SDS-PAGE. Maximum TGase activity was observed at pH 8.0 and 30 °C, mesophilic conditions (near 40 °C) resulted in total inactivation. A slight improvement in TGase activity was observed in the presence of Ca2+, it increased to 127.78 ± 9.62% at 35 mM but return to normal values at higher concentrations. Additionally, the enzyme activity decreased progressively in the presence of EDTA and STPP suggesting that the enzyme is Ca2+ dependent but this cofactor is being supplied by the fermented substrate. The partially purified TGase was used as an additive to modify the rheology of a cold-set gelatin gel achieving an increase in the gel strength and gumminess of 32.25% and 30.50% respectively.