Engineering and optimization of phosphate-responsive phytase expression in Pichia pastoris yeast for phytate hydrolysis
Staff Page link
Document Type
Journal Article
Publication Date
2020
Keywords
P PHO89, Phytase, Phytate, Pichia pastoris, Whole cell bio catalyst
DOI
10.1016/j.enzmictec.2020.109533
Abstract
Phytate is the major storage form of phosphorus in plants. It is present in cereals and raw materials of vegetable origin used in animal and human diets. However, non-ruminant animals have little phytase activity in their guts and, therefore, cannot digest phytate. As a result, almost all dietary phytate is discharged into the environment, causing phosphorus pollution. Phytate is also considered as an “antinutrient” for its ability to form insoluble and stable complexes with metal ions, thus reducing dietary absorption of essential minerals. It is a dire need to develop sustainable approaches for environmentally-friendly utilization for this valuable and abundant natural resource. To this end, we engineered Pichia pastoris to express and secrete phytase in a “made-to-order” fashion in response to external level of inorganic phosphate (Pi). Responsiveness to external Pi level was achieved by generating a Pi-responsive promoter library using directed evolution. The resultant yeast strains were proven to liberate Pi from wheat-based meal in a simulated in vitro digestion model. These yeast-based whole cell biocatalysts may serve as platform hosts with potential applications in food processing industry and animal waste treatment.
Source Publication
Enzyme and Microbial Technology
ISSN
01410229
Recommended Citation
Xie, Z.,Fong, W.,& Tsang, P. W. (2020). Engineering and optimization of phosphate-responsive phytase expression in Pichia pastoris yeast for phytate hydrolysis. Enzyme and Microbial Technology. http://dx.doi.org/10.1016/j.enzmictec.2020.109533