Characterization of highly gelatinous patatin storage protein from Pichia pastoris

Patatin is a useful plant protein with excellent gelation properties that could be used as a gelling agent in the food industry. However, the commercial production of patatin is limited because the traditional extraction methods are inefficient and time consuming. Production of patatin with gelation properties by microorganisms is a promising alternative route. In this study, 1424.5 mg/L patatin storage protein with great gelation properties could be obtained in a 5-L bioreactor after optimization of the signal peptide, the promoter, and the fed-batch process when a Pichia pastoris GS115, but not Escherichia coli, expression system was used. Compared with commercial potato-extracted patatins, P. pastoris-derived patatins showed better gelation properties, such as a lower gel-forming concentration and gelation temperature. In addition, the gel strength of P. pastoris-derived patatins was comparable with that of potato-extracted patatins. These results suggested that P. pastoris-derived patatins have the potential to replace current potato-derived ones, which are now widely used in plant-based meat products.