In situ product recovery

Silbiger, E., and Freeman, A., Continuous A1-Hydrocortisone Dehydrogenation with in Situ Product Recovery, Enzyme Microb. Technol., 13 869 (1991)... 

Apart from new catalytic methods, cascade conversions require new process technologies, such as in situ product recovery, reactor design, and compartmental-ization. In the long term, part of the present-day stoichiometric chemistry as well as bio- and chemocatalytic conversions in multi-step syntheses will gradually be replaced by cascade catalysis in concert, and full fermentations by cell factory design, or combinations thereof (Fig. 13.17). 

Search for natural flavour compounds with additional functionalities (e.g. antimicrobial properties) Improved downstream processing, especially in situ product-recovery techniques... 

Sidrsequent biotransformation converting a by-product to the desired product In situ product recovery by ... 

Vanillin Ferulic acid Amycolatopsis, Streptomyces Up to 18 g L" , 50 h, l-lOtyear In situ product recovery by crystallisation at more than 10 g L possible [8, 90, 91]... 

Phenylethanol L-Phenylalanine Diverse yeasts e.g. Saccharomyces and Kluyveromyces >10gL , 30 h, 0.5-1 tyear Fed-batch cultivation in situ product recovery by two-phase system with more than 25 g L in the organic phase possible [109,120]... 

Zelic, B., Gostovic, S., Vuorilehto, K., Vasic-Racki, D., and Takors, R. 2004. Process strategies to enhance pyruvate production with recombinant Escherichia coir. From repetitive fed-batch to in situ product recovery with fully integrated electrodialysis. Biotechnol. Bioeng. 85, 638-646. 

Another approach involves the addition of lactate dehydrogenase to the reaction that reduces the pyruvate to lactate. In addition, the use of an ion exchange resin allows in situ product recovery of the product amine that reduces product inhibition of the transaminase. 

Carstensen F, Apel A, and Wessling M. In situ product recovery Submerged membranes vs. external loop membranes. J. Membr. Sci. 2012 394-395 l-36. 

To fully exploit the concept of in situ product recovery (ISPR), some of these methods were combined. Some examples of in situ product recovery techniques are referred to in Table 1. Application of ISPR in the production of organic acids. 

Table 1. Some applications of in situ product recovery techniques ...

Recently, a novel process with simultaneous ABE fermentation and in situ product recovery with vacuum was reported (Mariano et al., 2011). Results indicated that fermentation coupled with in situ vacuum recovery led to complete substtate utilization, greater solvent productivity, and improved cell growth. 

A. succiniciproducens ATCC 53488 Anaerobic continuous process in complex medium with in situ product recovery 1.35 703 88 73 (146) 0.05 Meynial-SaUes et al. (2008)... 

Carstensen, F., Apel, A., Wesshng, M. (2012). In situ product recovery submerged membranes vs external loop membranes. Journal of Membrane Science, 394—395, 1—36. 

Commonly used online controls in industrial fermentations are the control of temperature, pressure, dissolved oxygen, and pH. Additional parameters to be controlled may be air/gas flow, feeding of substrates and supplements, or in situ product-recovery-related parameters (see Figure 1.6). Quantitative determination of the off-gas composition may further support control of the process. Complex and elaborate online measurements and controls should be avoided in an industrial production setting, although they can be useful during laboratory- or pilot-scale process development. 

Buque-Taboada, E.M., Straathof, A.J.J., and Heijnen, J.J., and van der Wielen, LA.M. (2006) In-situ product recovery (ISPR) by crystallization basic principles, design, and potential applications in whole-cell biocatalysis. Appl. Micmb. Biotechnol., 71, 1-12. 

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