Silicone-stimulated anthraquinone production and release by Morinda citrifolia in a two-liquid-phase system

In situ product removal (ISPR) in whole cell biotechnology during the last twenty years

This review sums up the activity in the field of in situ product removal in whole cell bioprocesses over the last 20 years. It gives a complete summary of ISPR operations with microbial cells and cites a series of interesting ISPR applications in plant and animal cell technology. All the ISPR projects with microbial cells are categorized according to their products, their ISPR techniques, and their applied configurations of the ISPR set-up. Research on ISPR application has primarily increased in the field of microbial production of aromas and organic acids such lactic acid over the last ten years. Apart from the field of de novo formation of bioproducts, ISPR is increasingly applied to microbial bioconversion processes. However, despite of the large number of microbial whole cell ISPR projects (approximately 250), very few processes have been transferred to an industrial scale. The proposed processes have mostly been too complex and consequently not cost effective. Therefore, this review emphasizes that the planning of a successful whole cell ISPR process should not only consider the choice of ISPR technique according to the physicochemical properties of the product, but also the potential configuration of the whole process set-up. Furthermore, additional process aspects, biological and legal constraint need to be considered from the very beginning for the design of an ISPR project. Finally, future trends of new, modified or improved ISPR techniques are given.

Partitioning bioreactors

A very wide range of methods has recently been employed to selectively partition fermentation products, substrates, or other metabolites to achieve an overall improvement in bioprocess performance. Techniques ranging from extraction and gas stripping to electrokinetic methods have been used to favorably influence the microenvironment of cells being cultivated in bioreactors. Virtually all types of cells, including animal cells, have benefitted by such selective partitioning and very high value fermentation products, such as monoclonal antibodies and secondary metabolites, have been produced using this process concept.