Whole-cell membrane bioreactor

Membrane Bioreactors with Membrane as Bio reactor 310 Enzyme Membrane Reactor 311 Whole-Cell Membrane Bioreactor 312 Membrane Bioreactors with Membrane as Separation... 

The modelling of enzymatic membrane reactors follows, in general, the same approach as described previously. In enzymatic membrane reactors the catalyst is a macromolecule (enzyme). It can be found either in a free form in the reactor or supported on the membrane surface, or inside the membrane porous structure by grafting it or in the form of a gel obtained by ultrafiltration. As in the case of the whole-cell membrane bioreactors discussed above, the proper calculation of the mass transfer characteristics is of great importance for the modelling of this type of reactor. One of the earliest models of enzymatic membrane bioreactors is by Salmon and Robertson [5.108]. These authors modelled an enzymatic membrane bioreactor, which was made of four coaxial compartments the enzyme is confined within one of the compartments, and one of the substrates is fed in a gaseous form. 

Applications of whole-cell biocatalytic membrane reactors, in the agro-food industry and in pharmaceutical and biomedical treatments are listed by Giorno and Drioli [3], Frazeres and Cabral [9] have reviewed the most important applications of enzyme membrane reactors such as hydrolysis of macromolecules, biotransformation of lipids, reactions with cofactors, synthesis of peptides, optical resolution of amino acids. Another widespread application of the membrane bioreactor is the wastewater treatment will be discussed in a separate section. 

Membrane bioreactor Asymmetric poly-sulfone membrane Diffusion of carbohydrates in liquid-filled pores Enzymatic hydrolysis of lactose Whole cells of Sutfolobus solfataricus entrapped in the tube wall 65... 

G. Catapano, G. lorio, E. Drioli, and M. Filosa, Experimental analysis of a cross-flow membrane bioreactor with entrapped whole cells Influence of trans-membrane pressure and substrate feed concentration on reactor performance, J. Membrane Sci 55 325 (1988). 

There is no commonly accepted definition of a membrane reactor but the term is applied to membrane (including liquid membrane) processes and devices whose function is to perform chemical conversion, coupling and combining chemical and transport processes, using the unique contacting features of membranes. As a rule, functional definition of this term includes fermentation, catalysis, separation of the products and their enrichment. A few published reviews at this time are available [98-104]. In most of pubhcations the bioreactors, based on enzymes or whole cells, impregnated into the membrane pores (immobihzed or supported hquid membranes) or deposited on the membrane surfaces are discussed. 

Catapano,G. Iorio,G. Drioli,E. Fi1osa, M. "Capillary Membrane Bioreactors with Entrapped Whole Cells a Theoretical Model" submitted for publication. 

Though MBR offer advantages over the more conventional bioreactors, they, themselves, are not completely free of problems. One such key problem, as previously noted, relates to changes in biocatalyst activity. This is a serious concern for whole-cell MBR, when the cells are immobilized in the membrane s pore structure. Diffusional limitations for nutri-... 

As an immobilization method, both for whole cells or enzymes, membrane bioreactors provide the advantages and drawbacks common to entrapment or adsorption methods. They nevertheless present particular assets. Mass transfer in the porous supports generally used (alginate, k-carrageenan, zeolites, silica) is a diffusion-controlled process, often becoming the overall rate-limiting step. This maybe overcome by the use of membrane modules. This equipment also avoids... 

Hai, F I., Yamamoto, K., Nakajima, F. and Fukushi, K. 2011. Application of a GAC-coated hollow fiber module to couple enzymatic degradation of dye on membrane to whole cell biodegradation within a membrane bioreactor./oitrna/ of Membrane Science, 389,67-75. 

A membrane bioreactor is a reactor in which separation and reaction, catalysed by enzymes or whole cells, can occur. It provides an opportunity to improve the productivity of bioconversion and fermentations by ... 

An enzyme membrane bioreactor can be created in different configurations the membrane can be used in order to confine or separate the biocatalyst from the reaction mixture furthermore, membranes can be used as a support for biocatalysts (enzymes or whole cells) immobilization. 

By substituting and Uqs = Ur into Eqs. (9) and (10), the dependencies of the drain current, on the activity of the ions are obtained. An analogous expression holds for CHEMFETs with another ion-selective membrane, ENFETs (enzyme-layer FETs), IMFETs (immuno-FETs), BIOFETs (with attached bioreactor containing bacteria, whole cells, tissue slices etc.) and REFETs (ISFETs with a constant activity of ions used as a reference to indicating ISFETs). 

DNA, coding for GFP and a-hemolysin, was introduced in GVs composed by eggPC, together with the whole T T machinery (T7 RNA polymerase and E. coll cell extracts), a-hemolysin, once synthesized, self-assembles at the membrane to form a pore (cut off 3kDa), allowing small solutes enter from outside. This bioreactor was able to sustain GFP expression for four days. GVs were prepared by centrifugation of a pre-formed w/o emulsion. 

The miniPERM Bioreactor (30, 31) consists of two components, the production module (40 ml) containing the ceUs and the nutrient module (600 ml of medirrm). The modules are separated by a semi-permeable dialysis membrane (MWCO 12.5 kDa) which retains the cells and mAb in the production module but allows metabolic waste products to diffuse out to the nutrient module. There is a permeable silicone rubber membrane for oxygenation and gas exchange in the production module. The whole unit rotates (up to 40 r.p.m.) within a CO2 incubator. It can be purchased as a complete disposable ready to use unit or the nutrient module (polycarbonate) can be autoclaved and reused at least ten times. 

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