UstiOpt | Defining optimum growth conditions for Ustilago maydis to increase the production of recombinant proteins

Abstract

The corn smut Ustilago maydis currently gains momentum as a potential producer of biotechnologically important molecules like biosurfactants or platform chemicals such as itaconic acid. However, with the recent discovery of an unconventional secretion pathway bypassing N-glycosylation also the application for protein expression becomes interesting. This system has already been successfully applied to export functional proteins like hydrolytic enzymes and antibody fragments. The aim of this proposal is the stepwise optimization of the unconventional secretion system to finally develop a novel cost effective expression platform for valuable proteins. Therefore, we intend to investigate the influence of culture conditions on protein production following a 4-step strategy: (i) Identify cultivation bottlenecks that limit the yields of unconventionally secreted proteins; (ii) Use these insights to define optimal growth conditions to obtain increased protein yields; (iii) Generate protease-deficient strains to enhance the stability of secreted proteins in the supernatant; (iv) If required, adapt the previously obtained medium conditions to the needs of protease-deficient strains. Optimized culture conditions will later on be applied for the production of cell-wall degrading enzymes and antibody fragments. 

Impact on bioeconomy

The efficient, sustainable and economical production of biomolecules is one key topic in bioeconomy. In particular, the production of proteins is a steadily increasing market, ranging from bulk enzymes to highly valuable biopharmaceuticals. In consequence, there is also an increasing demand for expression platforms to efficiently produce the whole range of proteins. In providing a novel expression system for valuable proteins lacking N-glycosylation, the UstiOpt project thus fully matches the scope of bioeconomy.

Expected results/ project products

Building on the complementary experiences of the two project partners linking fungal biology and bioprocess engineering we expect to strongly enhance the protein yields of our expression system. This will allow us to set up a competitive expression platform based on unconventional secretion in the near future which will complement existing expression systems in the framework of BioSC. As a result we will be able to cooperate with industrial partners to produce industrially relevant proteins.

Participating Core Groups

Coordinator/Contact
Dr. K. Schipper, Institute for Microbiology, Heinrich-Heine University Düsseldorf, Building 26.12.01 Room 64, Universitätsstraße 1, 40225 Düsseldorf; kerstin.schipper@hhu.de; Tel.: +49(0)211-81-10451

Partners

Dr. K. Schipper and Prof. Dr. M. Feldbrügge, Institute for Microbiology, HHU Düsseldorf
Dr. T. Schlepütz and Prof. Dr.-Ing. J. Büchs, Aachener Verfahrenstechnik, RWTH Aachen

Project duration

01.01.2015 – 31.12.2015

Funding budget

The total budget of UstiOpt is € 149.646,00. UstiOpt is part of the NRW-Strategieprojekt BioSC and thus funded by the Ministry of Innovation, Science and Research of the German State of North Rhine-Westphalia.