Rennet from plants

Some of the traditionally used industrial enzymes (e.g., rennet and papain) are prepared from animal and plant sources. Recent developments in industrial enzyme production have emphasized the microbial enzymes (Frost 1986). Microbial enzymes are very heat stable and have a broader pH optimum. Most of these enzymes are made by submerged cultivation of highly developed strains of microorganisms. Developments in... 

The characteristics of a rennet, however, depend on other conditions than those which could result from its habitat. Thus it is that Gerber, in a comparative study of rennet enzymes of a parasitic mushroom, Plerotus ostreaius, and of the plant on which it grows, Broussonetia papyrifera, found that they are very different. The rennet of the mushroom is very calciphile, very oxyphile, exceedingly sensitive to alkalis, and little resistant to heat that of the white mulberry, on the contrary, is moderately calciphile, moderately oxyphile, little sensitive to alkalis, and very resistant to heat. 

EndopepUdases (proteinoses) catalyse the hydrolysis of bonds within the peptide chain, forming variously sized cleavage peptides. They can be further subdivided into acidic, neutral and basic endopeptidases. Neutral and basic types can each be divided into Serine proteases (see) and thiol proteinases (see Thiol enzymes). Examples of animal endopeptidases are Pepsin (see). Rennet enzyme (see), Ttypsin (see), Elastase (see). Thrombin (see), Plasmin (see) and Renin (see). For examples of plant and bacterial endopeptidases, see Papain, Subtilisin, Bromelain. Endopeptidases have also been isolated from yeast and fungi. 

Fig. 2.S. Relationship between change in tissue or cell volume or weight from its initial (natural) value and the osmotic potential of the solution in which it is immersed. The osmotic potential in which there is no change in volume or weight gives the (water potential of protoplast) of the cell or tissue. Pp is equal but opposite in sign to the DPD (diffusion pressure deficit) or SF (suction force). (From T. A. Rennet-Clark, in Plant Physiology, vol. 2, pp. 105-192, edited by F. C. Steward, Academic Press, New York, 1959.)...

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