Expression of recombinant transglutaminase gene in Pichia pastoris and its uses in restructured meat products

•Pichia pastoris strain GS115 was used as host strain for TGase expression.•A high effective yeast expression system for transglutaminase was constructed.•Transglutaminase protein has potential application in restructured meat products.•The texture of restructured pork treated with MTG was improved.•High quality food can be achieved by crosslinking animal and plant protein by MTG. Transglutaminase is an effective enzyme that catalyzes the crosslinking of various meats, improves meat product quality, and is widely used in the meat industry. In this study, microbial transglutaminase (MTG) was expressed successfully in Pichia pastoris strain GS115, and the enzyme activity was approximately 0.70 U/ml. The recombinant MTG expressed in P. pastoris was used in the investigation of restructured pork and crosslinking of soy protein isolate (SPI) and chicken myofibrillar protein (MP). Results showed that the hardness, chewiness, and F1 of the restructured pork increased, and the adhesiveness decreased after MTG treatment, However, high temperature had greater effect on the texture of restructured pork after MTG treatment than that of the control. MTG can crosslink SPI component acidic subunits, subunits of β-conglycinin and MP component myosin heavy chain, and actin. MTG, as a food additive, can be successfully heterologously expressed, and the recombinant MTG has potential application in restructured meat products.