Improved glucoamylase production by less unstable strains ofAspergillus awamori

Vialta, Airton; Bonatelli, Renato

doi:10.1007/bf01025291

Cited by 3 publications

(1 citation statement)

References 9 publications

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“…The typical enzyme of choice in the food industry is the thermostable enzyme obtained from fungi, since this permits rapid reactions at high temperatures. Mold strains which have been known to produce this enzyme include Aspergillus awamori (Flor and Hayashida 1983; Vialta and Bonatelli 1988), A niger (Pazur et al 1971 ; Pandey and Radhakrishnan 1993), A. terreus (Ghosh et al 1990; Ali and Hossain 1991), Rhizopus oryzae (Ashikari et al 1989; Yu and Hang 1991), R . niveus and R. delemar (Ohnishi 1990 ;Ohnishi et al 1990).…”

Section: Introductionmentioning

confidence: 99%

Purification of Glucoamylase from Lactobacillus amylovorus ATCC 33621

James

Berger

1997

Current Microbiology

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An intracellular glucoamylase (E.C. 3.2.1.3) was purified to homogeneity from Lactobacillus amylovorus on a Fast Protein liquid chromatography System (FPLC) with a Mono Q ion-exchanger and two Superose 12 gel filtration columns arranged in series. The enzyme activity was quantified with a specific, chromogenic substrate, p-nitrophenyl-beta-maltoside. Preparative gel electrophoresis was then used to further purify active enzyme fractions. Native polyacrylamide gel electrophoresis (Native-PAGE) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme showed a single protein band of molecular weight 47 kDa. Glucoamylase activity of the purified protein was confirmed by its ability to degrade starch on a 0.025% starch-polyacrylamide gel stained with I2/KI. Glucoamylase exhibited optimum catalytic activity at pH 6.0 and 45 degrees C, and the enzyme had an isoelectric point near 4.39. The glucoamylase contained high levels of hydrophilic amino acids, comparable to fungal glucoamylases.

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Section: Introductionmentioning

confidence: 99%

Purification of Glucoamylase from Lactobacillus amylovorus ATCC 33621

James

Berger

1997

Current Microbiology

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Glucoamylase Research: An Overview

Pandey

1995

Starch Stärke

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This paper reviews the main features of glucoamylase research describing essentially more recent developments on microorganisms, production and properties of glucoamylases. It is an important industrial enzyme and is widely used in starch saccharification, brewing and distilling industry. Glucoamylase can be derived from a wide variety of sources including plants, animals and microorganisms. Most of the production techniques essentially, however, are based on microbial sources. It is an extracellular enzyme and has got second place (next to proteases) in world's distribution and sales among industrial enzymes. Most of the production of glucoamylase is carried out using liquid fermentation process. Technique of solid state fermentation, however, have also been employed for its production and recently this technique is gaining renewed interest from researchers for its production. The paper also describes aspects related with the purification and characterization of glucoamylase enzyme.

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Cultural conditions for production of glucoamylase from Lactobacillus amylovorus ATCC 33621

James

Lee

1995

Journal of Applied Bacteriology

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Lactobacillus amylovorus ATCC 33621 is an actively amylolytic bacterial strain which produces a cell-bound glucoamylase (EC 3.2.1.3). Conditions of growth and glucoamylase production were investigated using dextrose-free de Man-Rogosa-Sharpe (MRS) medium in a 1.5 l fermenter, with varying dextrin concentration (0.1-1.5% (w/v)), pH (4.5-6.5) and temperature (25-55 degrees C). Cell extracts were prepared by subjecting cells to treatment with a French Pressure cell in order to release intracellular proteins. Glucoamylase activity was then assayed. The effects of pH (4.0-9.0), temperature (15-85 degrees C) and substrate (dextrin and starch, 0-2% w/v) concentration on crude enzyme activity were investigated. Optimal growth was obtained in MRS medium containing 1% (w/v) dextrin, at pH 5.5 and 37 degrees C. Glucoamylase production was maximal at the late logarithmic phase of growth, during 16-18 h. Crude enzyme had a pH optimum of 6.0 and temperature optimum of 60 degrees C. With starch as the substrate, maximal activity was obtained at a concentration of 1.5% (w/v). The effects of ions and inhibitors on glucoamylase activity were also investigated. Enzyme activity was not significantly influenced by Ca2+ and EDTA at 1 mmol l-1 concentration; however Pb2+ and Co2+ were found to inhibit the activity at concentrations of 1 mmol l-1. The crude enzyme was found to be thermolabile when glucoamylase activity decreased after about 10 min exposure at 60 degrees C. This property can be exploited in the brewing of low calorie beers where only mild pasteurization treatments are used to inactivate enzymes. The elimination of residual enzyme effect would prevent further maltodextrin degradation and sweetening during long-term storage, thus helping to stabilize the flavour of beer.

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Improved glucoamylase production by less unstable strains ofAspergillus awamori

Cited by 3 publications

References 9 publications

Purification of Glucoamylase from Lactobacillus amylovorus ATCC 33621

Purification of Glucoamylase from Lactobacillus amylovorus ATCC 33621

Glucoamylase Research: An Overview

Cultural conditions for production of glucoamylase from Lactobacillus amylovorus ATCC 33621

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