Amylolytic Enzymes

Wong, Dominic W. S.

doi:10.1007/978-1-4757-2349-6_3

Cited by 4 publications

(3 citation statements)

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“…The GAI form consists of 616 amino acids with a catalytic site region (1-440), a heavily glycosilated Thr-and Serrich linker region (441-512) and a C-terminal region (513-616). The latter is missing in the GAII form, and is referred to as the granular starch-binding domain (Wong, 1995). The GA enzyme belongs to the glyBrought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 6/2/15 7:36 AM coside hydrolase 15 family.…”

Section: Resultsmentioning

confidence: 99%

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Immobilisation of Aspergillus oryzae α-amylase and Aspergillus niger glucoamylase enzymes as cross-linked enzyme aggregates

Şahutoğlu

Akgül

2015

Chemical Papers

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Cross-linked enzyme aggregates (CLEA) of Aspergillus oryzea α-amylase (AoAA) and Aspergillus niger glucoamylase (AnGA) were prepared using glutaraldehyde and dextran polyaldehyde as crosslinkers. The maximum activity recoveries for glutaraldehyde cross-linking were 21.8 % and 41.2 %, respectively. The addition of a proteic feeder (bovine serum albumin) exhibited a negative effect on the activity recoveries for both enzymes. Dextran polyaldehyde was used as a cross-linking agent instead of glutaraldehyde to reduce the activity losses. As a result, an activity recovery of 60.0 % was obtained for Aspergillus oryzea α-amylase. On the other hand, no activity recovery was observed for Aspergillus niger glucoamylase due to the latter enzyme's affinity for dextran.

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Section: Resultsmentioning

confidence: 99%

“…Amylases are glucosidases that catalyse the hydrolysis of α-D-1,4-glucosidic linkages of starch and related oligo-and polysaccharides by transferring a glucosyl residue (donor) to H 2 O (acceptor) (Wong, 1995). Starch is an important industrial raw material as well as being a major constituent of foodstuffs.…”

Section: Introductionmentioning

confidence: 99%

Immobilisation of Aspergillus oryzae α-amylase and Aspergillus niger glucoamylase enzymes as cross-linked enzyme aggregates

Şahutoğlu

Akgül

2015

Chemical Papers

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“…The enzymes belonging to the first group, the α -amylases (EC 3.2.1.1, α -D-glucan glucanohydrolase), cleaves the α (1→4) glycosidic bonds of the substrate (amylose or amylopectin chain) at internal positions (endo) to yield products (oligosaccharides with varying length an branched oligosaccharides called limit dextrins) with an α -configuration [ 2 , 3 ].…”

Section: Introductionmentioning

confidence: 99%

Modelling the Effects of Ageing Time of Starch on the Enzymatic Activity of Three Amylolytic Enzymes

Guerra

Pastrana

2012

The Scientific World Journal

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The effect of increasing ageing time (t) of starch on the activity of three amylolytic enzymes (Termamyl, San Super, and BAN) was investigated. Although all the enzymatic reactions follow michaelian kinetics, v max decreased significantly (P < 0.05) and K M increased (although not always significantly) with the increase in t. The conformational changes produced in the starch chains as a consequence of the ageing seemed to affect negatively the diffusivity of the starch to the active site of the enzymes and the release of the reaction products to the medium. A similar effect was observed when the enzymatic reactions were carried out with unaged starches supplemented with different concentrations of gelatine [G]. The inhibition in the amylolytic activities was best mathematically described by using three modified forms of the Michaelis-Menten model, which included a term to consider, respectively, the linear, exponential, and hyperbolic inhibitory effects of t and [G].

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Alcoholysis reactions from starch with α‐amylases

Santamaría¹,

Río²,

Saab³

et al. 1999

FEBS Letters

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The ability of K K-amylases from different sources to carry out reactions of alcoholysis was studied using methanol as substrate. It was found that while the enzymes from Aspergillus niger and Aspergillus oryzae, two well-studied saccharifying amylases, are capable of alcoholysis reactions, the classical bacterial liquefying K K-amylases from Bacillus licheniformis and Bacillus stearothermophilus are not. The effect of starch and methanol concentration, temperature and pH on the synthesis of glucosides with K K-amylase from A. niger was studied. Although methanol may inactivate K K-amylase, a 90% substrate relative conversion can be obtained in 20% methanol at a high starch concentration (15% w/v) due to a stabilizing effect of starch on the enzyme. As the products of alcoholysis are a series of methyloligosaccharides, from methyl-glucoside to methyl-hexomaltoside, alcoholysis was indirectly quantified by high performance liquid chromatography analysis of the total methyl-glucoside produced after the addition of glucoamylase to the K K-amylase reaction products. More alcoholysis was obtained from intact soluble starch than with maltodextrins or pre-hydrolyzed starch. The biotechnological implications of using starch as substrate for the production of alkyl-glucosides is analyzed in the context of these results.z 1999 Federation of European Biochemical Societies.

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Amylolytic Enzymes

Cited by 4 publications

References 154 publications

Immobilisation of Aspergillus oryzae α-amylase and Aspergillus niger glucoamylase enzymes as cross-linked enzyme aggregates

Immobilisation of Aspergillus oryzae α-amylase and Aspergillus niger glucoamylase enzymes as cross-linked enzyme aggregates

Modelling the Effects of Ageing Time of Starch on the Enzymatic Activity of Three Amylolytic Enzymes

Alcoholysis reactions from starch with α‐amylases

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