Team:Paris Bettencourt/Project/Phytase

Introduction

Phytic acid (C6H18O24P6) is a molecule that inhibits the absorption of different cations like iron, zinc, copper, magnesium, calcium and cobalt in the intestine by forming insoluble salts around these elements. The removal of these minerals from food through this process can contribute to mineral deficiencies.

Cereals, which are highly consumed in India, contain the highest levels of phytic acid.

Idli is mainly made of cereals. The majority of minerals present are not absorbed. We are looking for a solution to this bioavailability problem.

Figure 1: Phytic acid in complex with calcium, magnesium, zinc and iron


Phytase

Figure 2:Phytase hydrolyzes phytic acid.

Phytase could be a solution to this problem. Phytase is an enzyme which hydrolyzes phytates created by phytic acid when it is complexed to a mineral. Thanks to this, the cations will be liberated and may be absorbed by the organism.

Phytase is naturally produced by Saccharomyces cerevisiae (Veide, 2006). This yeast contains negative regulator genes, and because of it, the phytase is produced in very small quantities.

The negative regulators are produced by two important genes in Saccharomyces cerevisiae : PHO80 on chromosome 15 (325.249pb - 326.130pb) and PHO85 on chomosome 16 (492.018pb - 493.037pb). With the deletion of one or both of these genes, the phytase may be overproduced.


Design

To test our experiment, we used a colormetric kit to measure the quantity of phytic acid .


Results


Bibliography

Veide, J. & Andlid, T. Improved extracellular phytase activity in Saccharomyces cerevisiae by modifications in the PHO system. International Journal of Food Microbiology 108, 60-67 (2006).