Enzyme systems, plant cell

DE LUCA, V., BALSEVICH, J., TYLER, R.T., KURZ, W.G.W, Characterization of a novel V-methyltransferase (NMT) from Catharanthus roseus plants. Detection of NMT and other enzymes of the indole alkaloid biosynthetic pathway in different cell suspension culture systems. Plant Cell Rep., 1987,6,458-461. 

The extension of the useful storage life of plant and animal products beyond a few days at room temperature presents a series of complex biochemical, physical, microbial, and economic challenges. Respiratory enzyme systems and other enzymes ia these foods continue to function. Their reaction products can cause off-davors, darkening, and softening. Microbes contaminating the surface of plants or animals can grow ia cell exudates produced by bmises, peeling, or size reduction. Fresh plant and animal tissue can be contaminated by odors, dust, iasects, rodents, and microbes. 

Recovery. The principal purpose of recovery is to remove nonproteinaceous material from the enzyme preparation. Enzyme yields vary, sometimes exceeding 75%. Most industrial enzymes are secreted by a microorganism, and the first recovery step is often the removal of whole cells and other particulate matter (19) by centrifugation (20) or filtration (21). In the case of ceU-bound enzymes, the harvested cells can be used as is or dismpted by physical (eg, bead mills, high pressure homogenizer) and/or chemical (eg, solvent, detergent, lysozyme [9001 -63-2] or other lytic enzyme) techniques (22). Enzymes can be extracted from dismpted microbial cells, and ground animal (trypsin) or plant (papain) material by dilute salt solutions or aqueous two-phase systems (23). 

The bioreactor is the heart of any biochemical process in which enzymes, microbial, mammalian or plant cell systems are used for manufacture of a wide range of useful biological products. The performance of any bioreactor depends on many functions, such as those listed below ... 

The stress acting on particles is of high importance for many technical processes. As well as dispersion processes in two-phase systems (liquid/liquid or gas/Hquid), where the disintegration of particles is desirable, there are also a number of processes that may be adversely affected by particle disintegration. These include precipitation, agglomeration, crystalHsation processes, and also bio conversion with immobilised enzymes and the fermentation of sensitive microorganisms and animal and plant cells. 

Giri A, Dhingra V, GiriCC, Singh A, Ward OP, Narasu ML (2001) Biotransformations using plant cells, organ cultures and enzyme systems current trends and future prospects. Biotechnol Adv 19 175-199... 

Tissue culture, more frequently used as cell culture, enables animal and plant cells to be cultured in large numbers by techniques comparable to those used in microbiology but, because of the fragile nature of the cells, does require special cultural conditions. The culture media used must supply all the essential factors for growth, such as a wide range of amino acids, nucleotides, enzyme co-factors as well as indeterminate factors that can only be supplied in special products, e.g. foetal bovine serum. The environmental conditions must be carefully controlled, particularly pH, and this is frequently maintained by culturing in a bicarbonate buffer system and a carbon dioxide saturated atmosphere. 

Many reports on the effects of ozone and PAN on physiologic processes (net photosynthesis, stomatal response, and water relations) and on metallic activity (including in vivo and in vitro studies of individual enzymes, enzyme systems, metabolic pathways, metabolic pool relationships, cell organelles, and plant tissue studies) have appeared since 1964. 

---