Figure 7.

Upscaling of PGA production and export using B. megaterium and a 2 L bioreactor. The pH controlled batch cultivation of B. megaterium YYBm1 carrying pRBBm49 (encoding SP_lipA-PGA) was performed in complex medium (square) and optimized minimal medium (circle). B. megaterium MS941 carrying pRBBm23 (encoding SP_pga-PGA) was grown in semi-defined A5 medium (triangle). For induction of recombinant gene expression 5 g L^-1 xylose were added at the beginning of the cultivation. Samples were taken at indicated time points to determine cell dry weight (open) and PGA volumetric activity (solid).