Endo-enzymes producing

Two characteristics of the lyase that we have purified may be significant. First, the small molecular size of the protein may confer it a high mobility that could be helpful to its movement through host cell walls. In second place, it is an endo-type enzyme, fact that has been considered essential for maceration of plant tissues [35]. In this sense it is noteworthy that between the battery of pectic enzymes produced by FORL, this pectin lyase is the only protein that behaves as an endo-type. 

Endo pectinase activity was found to be very high for the strain FP-180 at a initial pH of 2.5 and 3.5 producing about 3 to 5 fold respectively in relation to A. niger. at 37°C. (Fig.2C). At other pH values the level of endo-pectinase secreted diminished as pH increased, and was practically negligible at 6.5 pHi showing a clear relation between pHi and enzyme production or secretion. Endo pectinase produced by A. n/gerwas very low as was the case of exo activity. However low production vras accentuated at very acidic pH values (i.e., 2.5 and 3.5). There was not a clear correlation in the production of this activity with the initial pH. 

Subtilisins are a class of related serine endo proteases produced by members of the Bacillus genus. The B.amvloliauefaciens subtilisin (BPN ) is well-characterized with regard to its DNA sequence 4 protein sequence (5), X-ray crystal structure (6) and kinetic properties (7). With this wealth of information available, BPN was chosen as the model enzyme for our recombinant approach. 

Influences of glucose, cellobiose, sophorose, and cellulose, when they were each used as a C-source, upon the formation of both cell-bound and extracellular cellulases during the growth of this pseudomonad are shown in Figure 1. Glucose supported the bacterium for an excellent growth, but only slightly stimulated the formation of cellulases, and the enzymes produced were distributed almost equally to the cell and the culture medium. In the cellulose and sophorose cultures, the formation of cellulases, particularly that of extracellular component, was enhanced prominently (exo-type synthesis), whereas cellobiose which was a main end-product of enzymatic cellulolysis stimulated the formation of cell-bound component (endo-type synthesis). Thus, an apparent difference in the distribution of extracellular and cell-bound cellulases was noticed between the cultures with cellobiose and sophorose or cellulose. 

Suitable vectors have been derived from the bacteriophage M13 which, except in its replicating form (RF), contains single-stranded circular DNA. The derivative M13 mpl, produced by insertion of part of the Escherichia coli lac operon, was mutated to give a single site for the restriction endo nuclease EcoRl within the gene for /8-D-galactosidase. This enzyme produces a blue colour when the hosts of this... 

When cultivated in a liquid medium with cellulose, Chaetomium thermophile produced extracellular cellulolytic enzymes. Ion-exchange chromatography and gel filtration gave three electrophoretically pure components a typical Cx endo-enzyme (pi 4.6, mol. wt. 4.1 x 10 ) active on carboxymethylcellulose in solution but of low effect on cellulose a Ci exo-enzyme (p7 4.6, mol. wt. 6.7 X 10 ) active on cellulose but hardly on carboxymethylcellulose and a... 

A slurry of the starch is cooked in the presence of a heat-stable bacterial endo-a-amylase. The enzyme hydrolyzes the a-l,4-glycosidic bonds in pregelatinized starch, the viscosity of the gel rapidly decreases, and maltodextrins are produced. The process may be terrninated at this point. The solution is purified and dried, and the maltodextrins are utilized as blandtasting functional ingredients in dry soup mixes, infant foods, sauces and gravy mixes, etc. 

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