Bioreactors design principles/products

The bioreactor is the central point of a fermentation process. It is here that the biotransformation takes place, that a raw material is turned into a desired and valued product Optimization of the rate of formation and yield of product within the bioreactor is a key part of optimizing the production process. Although the field of bioreactor design for submerged liquid fermentation systems is well developed, many of the principles cannot be directly translated to SSF systems. Solid beds and liquid broths are different solid beds are not as easy to mix as liquid broths, and due to poor heat transfer properties of solid substrate beds, heat removal is much more difficult in SSF than it is in SLF. 

The integration of new metagenomic data related to microbial diversity, and potential for new bioreactor designs based on ecological principles for mixed cultures of multispecies of microbes, represents the greatest potential for developing new bioprocesses and bioproducts for large-scale implementation and production (Shuler... 

Recently, Mottola [98] reported a sensor based on the disk-ring principle previously developed by Kamin and Wilson [99], and Wang and Lin [100]. Unlike Mottola s design, its forerunners involved no stationary ring electrode or rotation of the reactor part in addition, their reactor/electrode was located at the cell bottom. In Mottola s assembly, a product of an enzyme-catalysed reaction at a bioreactor rotated at a constant speed was hydrodynamically transported to a stationary ring electrode, where it was electrochemically monitored. The sample was transported to the detection imit by an tm-... 

An example of integration of part of the downstream processing in the actual bioreactor is two-liquid-phase biocatalysis (see above), in which the organic-solvent phase is used as extractant for the product. The liquid-impelled loop reactor (Fig. 7.3) is specifically designed for this purpose. It is based on the well-known air-lift principle, but instead of air, a water-immiscible, heavier or lighter organic solvent is injected. 

Some information must remain empirical and will never become a generally accepted first principle. After all, there can only be a small number of fundamental principles (according to the presiding conceptual framework of science). Empirical information is useful nonetheless, especially in the designs of utilitarian devices to be used with living systems. Designs of artificial kidney machines, bioreactors, automobiles, hospital ventilators, and even light bulbs are based on empirical information that serves to produce better products. 

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