IMMOBILIZED CELLS EBOOK DOWNLOAD
IMMOBILIZED CELLS EBOOK DOWNLOAD!
Due to space limitations, only a selected number of papers are listed. Preface. Keynote lecture. Why Immobilize? (C. Wandrey). Basics 1: physics. Determination. In the future, immobilized systems may be used extensively in organic solvents. STABILITY OF ENZYME ACTIVITY OF. IMMOBILIZED CELLS. One of the advantages for immobilization of enzymes and microbial cells is the enhancement of stability of a target enzyme. ABSTRACT: Immobilization is the method of entrapping/attaching the microbial or plant cells in a suitable matrix. Different methods such as encapsulation, gel.
|Published:||13 October 2014|
|PDF File Size:||14.24 Mb|
|ePub File Size:||4.9 Mb|
Can be reused again and again. Ideal for multi-enzyme reaction systems.
There was a problem providing the content you requested
Control of enzyme function immobilized cells easy. Suitable for industrial and medical use. Minimize effluent disposal problems. There are however, certain disadvantages also associated with immobilization. The possibility of loss of biological activity of an enzyme during immobilization or while it is in use.
Immobilization is an expensive affair often requiring sophisticated equipment. Immobilized enzymes are generally preferred over immobilized cells due to specificity immobilized cells yield the products in pure form.
However, there are several advantages of using immobilized multi-enzyme systems such as organelles and whole cells over immobilized enzymes.
The immobilized cells possess the natural environment with cofactor availability and also its regeneration capability and are particularly suitable for multiple enzymatic reactions.
The commonly employed techniques for immobilization of enzymes are—adsorption, entrapment, covalent binding and cross-linking. Adsorption involves the physical binding of enzymes or cells on the surface of an inert support. The support materials may be inorganic e. Adsorption of enzyme molecules on the inert support involves weak forces such as van der Waals forces and hydrogen bonds Fig.
Therefore, immobilized cells adsorbed enzymes can be easily removed by minor changes in pH, ionic strength or temperature.
This is a disadvantage for industrial use of enzymes. Enzymes can be immobilized by physical entrapment inside a polymer or a gel matrix. The size of the immobilized cells pores is such that the enzyme is retained while the substrate and product molecules pass through.
In this technique, commonly referred to as lattice entrapment, the enzyme or cell is immobilized cells subjected to strong binding forces and structural distortions. Some deactivation may however, occur during immobilization process due to changes in pH or temperature or addition of solvents.
Immobilized Cell Technology - Wikipedia
The matrices used for entrapping of enzymes include polyacrylamide gel, collagen, gelatin, starch, cellulose, silicone and rubber. Enzymes immobilized cells be entrapped by several ways.
Enzyme inclusion in gels: This is an entrapment of enzymes inside the gels Fig. Enzyme inclusion in fibres: The enzymes are trapped in a fibre format of the matrix Fig. Enzyme inclusion in microcapsules: In this case, the enzymes are trapped inside a microcapsule matrix Fig.
Immobilization of Enzymes and Cells: Methods, Effects and Applications
The hydrophobic and hydrophilic forms of the matrix polymerise to form a microcapsule containing enzyme molecules inside. The major limitation for entrapment of enzymes is their leakage from the matrix. Most workers prefer immobilized cells use the technique of entrapment for immobilization of whole cells.
Entrapped cells are in use for industrial production of amino acids L-isoleucine, L-aspartic acidL-malic acid and hydroquinone.
Microencapsulation is a type immobilized cells entrapment. It refers to the process of spherical particle formation wherein a liquid or suspension is enclosed in a semipermeable membrane.