Biochemical Engineering

First successful examples of Biochemical Engineering can be named with the industrial production of baker’s yeast or the lactic acid process starting at 1880 or 1881, respectively. The well-known acetone-butanol-ethanol (ABE) production, technically realised during the First World War, is another example of successful biochemical engineering. Moreover the production of antibiotics with the help of Penicillium spec. in submerse production processes should be outlined as well and started industrially at 1942. These pioneering examples have in common that bioprocess development was based on the optimisation of culture conditions to achieve best growth and product formation. Cells were regarded as black boxes at these days.

This attitude changed fundamentally with the onset of metabolic engineering activities in the 1990s. Applying recombinant technologies and combining them with the engineering approach for identifying promising metabolic engineering targets, a novel road towards efficient development of microbial producers was enabled. It was (and still is) the explicit task of engineers to support metabolic engineering with quantitative tools to identify promising metabolic engineering targets also predicting expected strain performance.

Metabolic engineering has obviously changed the view of bioprocess development significantly. While external condition were solely optimised in the pioneering days of biochemical engineering, the analysis of intracellular metabolic activities gained more and more importance for successful bioprocess development. This development was even amplified by tremendous developments in cellular analytics, i.e. by the birth of the “omics” technologies. Being able to study multiple levels of cellular regulation based on experimental data, the cellular view became more and more profound – and complex. This resulted in systems biology. This research field covers the quantitative, model-based analysis of the complex cell aiming at a holistic understanding of the same. Genome-scale models including metabolic activities, regulatory networks and signal conduction processes mirror the complexity of the biological systems. At the same time the engineering perspective was also considered in the novel field of synthetic biology. The fundamental engineering approach (which consists of system’s modularisation, modelling, re-wiring and holistic system analysis) represents the backbone of synthetic biology. The complexity of biological system is broken down to individual modules which are modelled individually. After they have been understood in detail, these modules can be re-assembled such that new-to-nature systems are constructed and access to novel compounds is enabled.

Clearly, metabolic engineering, systems biology and synthetic biology have expanded the scope of classical biochemical engineering by integrating cellular complexity in the optimisation process that finally yields at an optimised stain and/or industrial production approach.