Evaluation of different expression systems for the heterologous expression of pyranose 2-oxidase from Trametes multicolor in E. coli
1 Food Biotechnology Lab, Department of Food Sciences and Technology, BOKU - University of Natural Resources and Applied Life Sciences Vienna, Austria
2 Research Centre Applied Biocatalysis, Graz, Austria
3 School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
4 Department of Nanobiotechnology, BOKU - University of Natural Resources and Applied Life Sciences Vienna, Austria
Microbial Cell Factories 2010, 9:14 doi:10.1186/1475-2859-9-14Published: 9 March 2010
The heterologous production of the industrially relevant fungal enzyme pyranose 2-oxidase in the prokaryotic host E. coli was investigated using 3 different expression systems, i.e. the well-studied T7 RNA polymerase based pET21d+, the L-arabinose inducible pBAD and the pCOLD system. Preliminary experiments were done in shaking flasks at 25°C and optimized induction conditions to compare the productivity levels of the different expression systems. The pET21d+ and the pCOLD system gave 29 U/L·h and 14 U/L·h of active pyranose 2-oxidase, respectively, whereas the pBAD system only produced 6 U/L·h. Process conditions for batch fermentations were optimized for the pET21d+ and the pCOLD systems in order to reduce the formation of inactive inclusion bodies. The highest productivity rate with the pET21d+ expression system in batch fermentations was determined at 25°C with 32 U/L·h. The pCOLD system showed the highest productivity rate (19 U/L·h) at 25°C and induction from the start of the cultivation. Using the pCOLD system in a fed batch fermentation at 25°C with a specific growth rate of μ = 0.15 h-1resulted in the highest productivity rate of active pyranose oxidase with 206 U/L·h.