Enzyme cell wall lytic

Lin et al. (55,63) have described a method to lyse baker s yeast cells using subcritical and SCF CO2 (25-35°C, 7-34 MPa). In a batch process, pressurized CO2 was allowed to permeate the cells for a fixed time, followed by rapid depressurization. The rapid depressurization resulted in explosive expansion of the CO2 within the cells, leading to cell rupture and release of the cellular components. SCF CO2 at 35°C and 20 MPa was the most effective for enzyme release. Higher temperatures were more effective at cell disruption, but they also resulted in lower activity of the released enzymes. Enzyme release from baker s yeast cells was further enhanced with the addition of a cell-wall-lytic enzyme, (3-glucuronidase, to the cell mass before pressurization (55). 

Microbial cell-wall-lytic enzymes are widely used in the laboratory for cell breakage, proto-plasting of yeasts and bacteria, and for studies of the structure and composition of microbial cell walls (J ). Recently lytic systems have come under consideration as a specific and chemically mild way to rupture microbial cells on an industrial scale (2 ). There appear to be attractive commercial applications of lytic systems for the recovery of enzymes, antigens and other recombinant products accumulated within cells, for upgrading of microbial biomass for food and feed uses (4 5) and for the manufacture of functional biopolymers from cell wall carbohydrates (6). 

The methods used to determine cell wall lytic activity of enzyme preparations vary considerably in different laboratories. The following approaches have been used ... 

Cell Wall Lytic Enzymes Which Act by the Sequential Removal of Single Glucose Residues from / -( - 3)-Glucans. Exo-... 

From the applied point of view where cell wall lytic enzymes are to be used for improvement in protein recovery and protein processing from yeast cells, a number of areas are much in need for further research. One of the problems of using microbial enzymes for this purpose is their inducible nature. Investigations have shown that yeast cell walls are the best inducers, followed by /3-(l —>3)- and / -(1 6)-glucans, while... 

Strange, R. E., and E. A. Dark Cell-wall lytic enzymes at sporulation and spore germination in Bacillus species. J. Gen. Microbiol. 17, 525 (1957)-... 

Many microorganisms produce enzymes that lyse the cell wall of yeast. The most extensive work has been done with the lytic system from Arthrobacter sp., Cytophaga sp., Oerskovia, Bacillus circulans, Rhizopus, Tri-choderma, Penicillium, Pellicularia sp., Rhizoctonia, and Streptomyces sp. (3-9). 

The lytic enzyme systems, active against yeast cell walls, usually contain l,3-/ -glucanases, proteases, mannanases, chitinases, and 1,6-) -glucanases. The proportion of those enzyme activities, their action pattern, synergism, and dependence on inhibitors constitute the activity profile... 

Enzyme Treatment. There are a number of enzymes which hydrolyze the microbial cell wall constituents. Enzymes exhibiting these activities include lysozyme, enzyme from snail extract and lytic enzyme systems of microbial origin composed of proteases,... 

Mainly used to indicate living cells after digestion of the outer cell wall via lytic enzymes. The protoplasma of these cells is still enclosed by the undestroyed plasma-membrane. 

The only way for microbes to enter a healthy plant is via the stomata or at sites of injury, inflicted by herbivory, wind, or other accidents. At the site of wounding, plants often accumulate suberin, lignin, callose, gums, or other resinous substances which close off the respective areas (4.17). In addition, antimicrobial agents are produced such as lysozyme and chitinase, lytic enzymes stored in the vacuole which can degrade bacterial and fungal cell walls, protease inhibitors which can inhibit microbial proteases, or secondary metabolites with antimicrobial activity. 

Chemical structures of the cell wall peptidoglycans and points of attack by different lytic enzymes. 

Lytic enzyme systems provide a chemically mild, low-shear and catalytically specific alternative to mechanical cell disruption. Depending on the particular lytic system employed and its purity, the enzymes may be engineered to attack cell wall components alone, without product damage. The enzyme lysozyme, active against some bacterial cell walls, has been used to harvest bovine growth hormone granules from 12. coli (8), and a membrane-associated hydroxylase complex from . putida (11) use of other bacteriolytic enzymes from a variety of microbial sources have also been reported (3). 

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