Abstract
Microbial phytases (EC 3.1.3.8) catalyse dephosphorylation of phytic acid, which is the primary storage
compound for phosphorous in cereal kernels. The negatively charged phosphates in phytic acid chelate iron
(Fe3+) and thus retards iron bioavailability in humans 1. Supplementation of microbial phytase can improve
iron absorption from cereal-based diets 2. In order for phytase to catalyse iron release in vivo the phytase
must be robust to low pH and proteolysis in the gastric ventricle. Our work has compared the robustness of
five different microbial phytases, evaluating thermal stability, activity retention, and extent of
dephosphorylation of phytic acid in a simulated low pH/pepsin gastric environment. The five phytases
responded differently to the robustness parameters: The Peniophora lycii phytase (Ronozyme NP) was the
most thermostable, but the least robust enzyme at low pH, whereas the two tested Aspergillus niger
phytases (SukaPhy phytase and a cloned A. niger enzyme), and an Escherichia coli phytase proved to be
most resistant to low pH and pepsin hydrolysis. The phytase from Citrobacter braakii (Ronozyme HiPhos)
showed intermediate robustness.
| Original language | English |
|---|---|
| Title of host publication | Abstract Book - DTU Sustain Conference 2014 |
| Number of pages | 1 |
| Place of Publication | Kgs. Lyngby |
| Publisher | Technical University of Denmark |
| Publication date | 2014 |
| Publication status | Published - 2014 |
| Event | DTU Sustain Conference 2014 - Technical University of Denmark, Lyngby, Denmark Duration: 17 Dec 2014 → 17 Dec 2014 http://www.sustain.dtu.dk/ |
Conference
| Conference | DTU Sustain Conference 2014 |
|---|---|
| Location | Technical University of Denmark |
| Country/Territory | Denmark |
| City | Lyngby |
| Period | 17/12/2014 → 17/12/2014 |
| Internet address |