Although A. niger -a versatile and efficient cell-factory in industrial bioprocesses- shows a high production capacity and secretion efficiency, obtainable yields of recombinant proteins are considerably lower than those of homologous proteins. Therefore current research is focussed on the optimisation of cultivation processes resulting in an increased, controlled and tailored formation of desired products. The contribution displays the influence of pH-value, volumetric power input and inoculum concentration on the observed morphology and the formation of homologous recombinant beta-fructofuranosidase under a constitutive promoter as model product. Batch cultivations are monitored and every step of the protein formation path is shown: The expression of the beta-fructofuranosidase gene as well as of genes, which show significant expression levels within the bioprocess, are quantified via real-time PCR. Intra- and extracellular enzyme activities are measured and related to gene expression levels and observed morphology, pellet size and concentration. In conclusion, the protein formation in batch processes is linked to defined cultivation conditions to reveal bottlenecks within the complex production path from gene to product. Therefore the shown results indicate targets for improving, optimising and controlling industrial bioprocesses.
Full conference title:
7th International Aspergillus Meeting
- Asperfest 7 (2010)