Enzymes amyloglucosidase

K. Bock and H. Pedersen, The substrate specificity of the enzyme amyloglucosidase (AMG). Part I. Deoxy derivatives, Acta Chem. Scand. B, 41 (1987) 617—628. 

Figure 1 Expanded chromatograms from Dionex ion chromatograph of enzyme hydrolysates of corn and potato starch, the use of a single enzyme, amyloglucosidase (AMG), and a mixture of AMG, a-amylase (a-A), and pullulanase (PU), to show the effect on hydrolysis of limit dextrin. Anion exchange column AS6, with pulsed amperometric detection. Gradient flow solvents (1) ISOmmolT NaOH and (2) ISOmmoll NaOH + 500mmol I NaOOCCHs. Postcolumn addition of 0.3mmoll NaOH.

Starch, and individual sugars, may be determined in meat products using enzymatic kit methods. Starch is extracted from the sample and hydrolyzed by the enzyme amyloglucosidase to D-glucose. The... 

By far, the oldest sizing compounds are starch and starch derivatives, which are inexpensive and easily and most commonly removed by enzymatic means (Tester and Karkalas, 2002) but cannot be recycled (Trauter, 1993). Combinations of amylase enzymes, amyloglucosidase and puUanase ( diastase ) decompose starch to sugars (see Fig. 8.2) which, although nontoxic, increase the BOD (biochemical... 

Enzymatic hydrolysis was employed to investigate the integrity of the starch-wrapped SWNTs in water. To this end, a commercially available enzyme, amyloglucosidase, from Rhizopus mold was added to an aqueous suspension of the starch-wrapped SWNTs. Within 10 min, the nanotubes precipitated out of the suspension as indicated by light-scattering measurements and confirmed by NMR spectroscopy (see NMR Spectroscopy in Solution, Techniques). 

Saccharification. Saccharifications were performed with amyloglucosidase (AMG) or amyloglucosidase/pullulanase (Dextrozyme) at a dose of 0.18 AG/units/gram DS for 48 hours at 60 C, pH 4.3-4.5. One AG unit is the amount of enzyme which hydrolyzes 1.0 micromole of maltose per minute at 25 C, pH 4.3. 

Starch derived from maize, potatoes, barley, cassava or other somces must be pretreated with hydrolytic enzymes (amylases, amyloglucosidase, proteases), which carry out liquefaction, saccharification and protein hydrolysis, respectively, before it can be fermented by yeasts and other microorganisms into potable or non-potable alcohol. Enzymes can be added in the form of malt (germinated barley) or koji (germinated rice), but this is expensive. Therefore, industrial enzymes have nearly totally replaced malt and koji as enzyme sources, thereby not only improving the economics but also the predictability of the process. 

In a second example, Storey et al. demonstrated that one could covalently immobilize amyloglucosidase using hydrophilic prepolymers. A 5-mg/ml solution of the enzyme was mixed with an equal volume of prepolymer. The method was judged superior as a support for enzyme immobilization. The percent activity inuno-bili/ed in the polyurethane foams was 25 1.5%. 

The action of amyloglucosidase from Aspergillus niger on various synthetic polyglucoses has been examined.242 This enzyme is an exoglucosidase... 

The kit includes necessary enzymes (thermostable a-amylase and amyloglucosidase), some reagents (buffer concentrate and glucose oxidase/peroxidase [GOPOD] reagent) and standards (glucose solution and com starch) to carry out 100 starch determinations. The other reagents required for this procedure may be obtained from any chemical supplier. 

Place tube in a 50°C water bath. Add 4 ml of 200 mM sodium acetate buffer. Add 0.1 ml amyloglucosidase (20 U) using a positive-displacement pipettor. Add 0.1 ml water instead of enzyme to sample blank. 

For some foods, incomplete extraction of color is obtained, probably due to the high binding affinity of dyes to the bulk of the food matrix, especially to proteins, lipids, and carbohydrates (156,161,162). This problem can be overcome by the use of selected solvents or enzymes to digest the food prior to extraction. Petroleum ether can be used to extract lipids (163). Acetone can be used to remove lipids and coagulate protein (164). Enzymes, such as amyloglucosidase (165,166), papain (167), lipase, pectinase, cellulase, and phospholipase, added to the sample and incubated under optimum pH and temperature conditions release synthetic colors bound to or associated with the food matrix. Furthermore, enzyme digestion can solubilize some foods, enabling analysis to be continued (156). 

Among hydrolases with allergenic properties used in the food industry there are a-amylases, amyloglucosidases, glucoamylases, cellulases, hemicellulases, pecti-nases, lipoxygenases, and xylanases (Bindslev-Jensen et al. 2006, Cullinan et al. 1997, Houba et al. 1997, Kanerva and Vanhanen 1999, 2001, Scheibe et al. 2001). Most of these enzymes are synthesized by A. otyzae fungi or Bacillus subtilis bacteria. 

---