Production of recombinant proteins suitable for use in food using the Lactococcus lactis expression system: levansucrase and plant sweet proteins
Project no. 23099 · Status: Kapanmış (Yayın bekleniyor) · 2021
Summary
<p>Numerous recombinant proteins are produced for biotechnological applications, and many different expression systems have been developed for this purpose. Escherichia coli, the organism most used for recombinant protein production, has limiting factors such as the inability to produce some plant and animal proteins correctly, plasmids transferred to cells are thrown out of the cell over time, toxic properties of chemical inducers used for gene expression, and endotoxin contamination. Lactococcus lactis, a Gram-positive bacterium naturally found in fermented food products such as cheese, yoghurt and pickles, has become a good alternative system with its well-known genome features, good functioning of protein secretion systems outside the cell and its usability especially for the production of proteins that can be added directly to foods. </p><p><br></p><p>The aim of the project is to use the L.lactis expression system in the production of levansucrase enzyme, which breaks down sucrose and catalyzes the formation of prebiotic fructose polymers, and sweet plant protein-like proteins that have no calories and can be used as sweeteners. For this purpose, genes encoding levansucrase and plant sweet protein-like proteins will be cloned into the pLEB825 plasmid under the PnisA promoter and the resulting recombinant plasmids will be transferred to Lactococcus lactis NZ9000 cells. The recombinant L.lactis cells obtained in the project studies will be enabled to produce proteins and the proteins secreted outside the cells will be purified. In addition, the production possibilities of the obtained recombinant cells in different environments containing whey, which is an easily degradable waste due to its low sugar content, will be examined and the reproduction kinetics of the recombinant cells and optimum breeding conditions will be determined.</p><p>In summary, the project aims to recombinantly produce two different protein types in a food-safe expression system, which will reduce the simple sugar content in foods and produce healthy sugar-containing foods, and to carry out this recombinant production by utilizing food waste.</p>