Enzyme lysis, microbial

Microbial 3-Glucan Hydrolases and Lysis of Plant Cell Wall Polymers. Many soil and aerial pathogens gain access to host tissues by enzymic lysis of epidermal cell walls of roots, leaves, stems, etc.. Phytopathogenic organisms possess an array of inducible polysaccharide hydrolases capable of degrading the complex polysaccharides of the plant cell wall (, 10). The... 

Within organisms, organic sulfur is present predominantly as the amino acids cysteine and methionine, and the algal and bacterial osmolyte, dimethylsulfoniopropionate (DMSP). The latter also serves as an antioxidant and cryoprotectant. Small amounts of organosulfur are also present in some polysaccharides, lipids, vitamins, enzymes, and in the iron-sulfur protein ferrodoxin. Cell lysis and microbial degradation releases... 

Wall Lysis by Exogenous Enzymes. Because of the limited availability and high cost of snail digestive fluid, extracellular microbial enzymes appear to offer the best means to weaken or rupture cell walls. 

The many circumstances leading to the Henri equation for enzyme conversion of soluble substrates are first noted, followed by some kinetic forms for particulate and polymer hydrolysis. Effects common to immobilized enzyme systems are summarized. Illustrative applications discussed Include metabolic kinetics, lipid hydrolysis, enzymatic cell lysis, starch liquefaction, microenvironment influences, colloidal forces, and enzyme deactivation, all topics of interest to the larger themes of kinetics and thermodynamics of microbial systems. 

The foremost difference between extracellular and intracellular enzymes purification is the need for cell disruption. If the enzyme is intracellular, extraction takes place after cell lysis, which adds an additional step and costs to the purification process. This is not required for extracellular enzymes. Once the cells have been broken down and the intercellular enzymes are released, purification techniques similar to those used with extracellular enzymes are applicable. Intracellular enzymes from animal sources can be easily extracted due to the absence of a cell wall, whereas enzymes from plant and microbial cells require more force due to their rigid cell wall structure. Another approach to facilitate intracellular cell isolation is by genetic engineering. Details of genetic engineering are given in Section 1.6. 

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