Protein Expression with Synthetic Biology

Biological cell factories can sustainably produce a wide range of products such as fuels or pharmaceuticals. In this way, they support more environmentally friendly industrial processes and the necessary shift towards a bio-based economy. However, the development of these cell factories is currently time-consuming and labour-intensive because, among other things, attention must be paid to the integrity of the organism used. However, by transferring the reaction from inside the cell to the free solution, these limitations can be overcome. Therefore, the sufficient provision of proteins for synthetic enzyme cascades (in vitro) represents an important field of development.

The yeast Pichia pastoris is one of the most important heterologous expression systems in biotechnology. In addition to the secretion of proteins from the cell, post-translational modifications (PTM) such as glycosylation are also possible. Secreted proteins can subsequently be applied more cost-effectively on an industrial scale. Although P. pastoris is widely used for industrial applications and has already been intensively studied, an efficient strategy that allows the systematic identification of optimal expression and secretion conditions is lacking. Therefore, a modular toolbox of standardised genetic elements and different secretion signals was developed at the Department of Chemistry of Biogenic Resources (keyword synthetic biology). These elements can be randomly combined into large and diverse libraries in an uncomplicated way using hierarchical assembly. The identification of the best combination is carried out robotically in high-throughput screening (link). Using the developed method, new combinations could be identified that led to increased protein secretion. The flexible design of the platform provided here enables efficient optimisation in the high-throughput process and thus represents a valuable resource for future development projects.