Enzymes Amyloglucosidase Research Articles

Optimisation of α-Amylase and Amyloglucosidase Enzyme Concentration on Glucose Syrup Characteristics from Purple Sweet Potato (Ipomoea batatas L var. Antin 2)

This study investigated the impact of α-amylase and amyloglucosidase enzyme concentrations on purple sweet potato glucose syrup production. The results demonstrated that higher α-amylase levels enhanced total dissolved solids and reduced sugar content during liquefaction, while an optimal amyloglucosidase concentration of 0.8 mL/kg maximized yield and reduced sugar content during saccharification. The resulting syrup exhibited high antioxidant activity and adjustable viscosity. Enzymatic hydrolysis using amyloglucosidase proved superior to acid hydrolysis in producing high-quality glucose syrup. Purple sweet potato glucose syrup emerges as a promising functional natural sweetener with potential health benefits and commercial value.

Production, Characterization, Kinetics, and Thermodynamics Analysis of Amyloglucosidase from Fungal Consortium.

The current study aimed to produce an amyloglucosidase enzyme from the fungal consortium. The best amylolytic fungal consortia were identified as Alternaria alternata and Aspergillus niger through the 18S rDNA technique. Fermentation kinetics and various nutritional and cultural parameters were analyzed. Maximum production was obtained in M4 media, pH 5.5, 30°C, and 4mL inoculum at 150rpm after 72h of incubation. Along with that, sodium nitrate at 2.5%, maltose, beef extract 1%, zinc sulfate (0.1%), and Tween 80 (0.1%) supported the maximum amyloglucosidase production. Amyloglucosidase was partially purified up to 1.6 purification fold with a specific activity of 1.84 Umg-1 in a stepwise manner by ammonium sulfate purification, dialysis, and ion exchange chromatography. The AMG enzyme also revealed maximum activity at 50°C with 5.0 pH. Upon the kinetic analysis, the specific yield coefficient Yp/x and volumetric rates Qp and Qx were also found to be significant in the above optimized conditions. The Km value 0.33mgmL-1 and Vmax 26.31 U mL-1 were obtained at 1% soluble starch substrate. Thermodynamic parameters for soluble starch hydrolysis were as follows: ΔH = 48.78kJmol-1, (Ea) = - 46.0kJmol-1, and ΔS = - 43.10Jmol-1K-1. This finding indicates the indigenously isolated fungal consortium can be the best candidate for industrial applications.

Investigation of the Effect of Pectinase and Amyloglucosidase Enzyme Mixture on Clarification of Apple Juice

Investigation of the Effect of Pectinase and Amyloglucosidase Enzyme Mixture on Clarification of Apple Juice

Biological characterization of microwave based synthesized ZnO and Ce doped ZnO nanoflowers impeded chitosan matrix with enhanced antioxidant and anti-diabetic properties

The chitosan matrix was used as a substrate for ZnO nanoflowers (ZnO/CH) and Ce-doped ZnO nanoflowers (Ce-ZnO/CH) by microwave-induced hydrothermal synthesis processes. The obtained hybrid structures were assessed as enhanced antioxidant and antidiabetic agents considering the synergetic effect of the different components. The integration of chitosan and cerium induced significantly the biological activity of ZnO flower-like particles. Ce-doped ZnO nano-flowers show higher activities than both ZnO nanoflowers and ZnO/CH composite reflecting the strong effect of surface electrons that were formed by the doping process as compared to the high interactive interface of the chitosan substrate. As an antioxidant the synthetic Ce-ZnO/CH composite achieved remarkable scavenging efficiencies for DPPH (92.4 ± 1.33 %), nitric oxide (95.2 ± 1.81 %), ABTS (90.4 ± 1.64 %), and superoxide (52.8 ± 1.22 %) radicals which are significantly higher values than Ascorbic acid as standard and the commercially used ZnO nanoparticles. Also, its antidiabetic efficiency enhanced greatly achieving strong inhibition effects on porcine α-amylase (93.6 ± 1.66 %), crude α-amylase (88.7 ± 1.82 %), pancreatic α-glucosidase (98.7 ± 1.26 %), crude intestinal α-glucosidase (96.8 ± 1.16 %), and amyloglucosidase (97.2 ± 1.72 %) enzymes. The recognized inhibition percentages are notably higher than the determined percentages using miglitol drug and slightly higher than acarbose. This recommends the Ce-ZnO/CH composite as a potential antidiabetic and antioxidant agent compared with the high cost and the reported side effects of the commonly used chemical drug.

Urea addition during hydrolysis for increased ethanol yield from white sweet potato: a promising strategy

Bioethanol is mainly produced from corn worldwide, but many countries face challenges in producing sufficient corn for this purpose. White sweet potato (Ipomoea batatas Linneaus) has a lower nutritional value and less carotene pigment compared to other sweet potatoes, which may make it less desirable as a food source in some regions. However, the affordability of white sweet potato could make it an attractive option for bioethanol production in areas where corn is not readily available. This study investigated the use of white sweet potatoes powder (40 mesh sieve) as a feedstock for ethanol production using Saccharomyces cerevisiae yeast. Optimization of the fermentation process was carried out using response surface methodology (RSM). Results showed that an ethanol yield of 18% could be achieved by applying pH at 4.5 and urea concentration of 60 mg/L. These findings suggest that the addition of urea during hydrolysis of white sweet potato is a promising alternative method for bioethanol production which contained higher etnaol yield compated to the previous finding that utilized amyloglucosidase enzyme during hydrolysis.

Insight into the Potential Antioxidant and Antidiabetic Activities of Scrolled Kaolinite Single Sheet (KNs) and Its Composite with ZnO Nanoparticles: Synergetic Studies

The kaolinite sheets were scrolled by sonication-induced chemical delamination processes into well-developed nanotubes (KNs) which were used as substrates for microwave-based ZnO nanoparticles (ZnO/KNs). The biological activities of synthetic ZnO/KNs structures, in terms of the antioxidant and antidiabetic properties, were assessed in comparative studies with the separated phases of the synthetic ZnO and KNs as well as the commercially used ZnO. The KNs substrate resulted in a notable enhancement in the antioxidant and antidiabetic properties of ZnO, which was assigned positive influence on the surface area, interactive interfaces, charge separation, and agglomeration properties of ZnO in addition to the detectable bioactive properties of the KNs structure. The ZnO/KNs structure achieved remarkable scavenging efficiencies for 1, 1-diphenyl-2-picrylhydrazil (DPPH) (89.8 ± 1.57%), nitric oxide (90.6 ± 1.63%), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) (86.8 ± 1.28%), and superoxide (43.9 ± 1.72%) radicals. Additionally, it shows high inhibition effects on porcine α-amylase (84.3 ± 1.92%), crude α-amylase (70.6 ± 1.37%), pancreatic α-Glucosidase (94.7 ± 1.54%), crude α-Glucosidase (95.4 ± 1.64%), and amyloglucosidase (95.3 ± 1.32%) enzymes. This antidiabetic activity is significantly higher than the activity of miglitol and close to or slightly higher than acarbose, which leads us to recommend the use of ZnO/KNs when considering the cost and side effects of the commercially used drugs.

Effect of enzymatic hydrolysis and nitrogen on Saccharomyces cerevisiae β-glucan production from Manihot utilissima and Maranta arunadinacea waste

This experiment utilised cassava (Manihot utillissima) and arrowroot (Maranta arunadinacea) wastes as the medium of propagation of Saccharomyces cerevisiae to produce β-glucan. The amyloglucosidase hydrolysed the waste, followed by fermentation in the nitrogenous medium by S. cerevisiae. The β-glucan pellet was extracted using 2% NaOH alkaline solution at 90°C for 5 hours, followed by a series of centrifugation processes. The highest glucose concentration from hydrolysis resulted from adding 57.5 mg amyloglucosidase enzyme for arrowroot waste with 95.93% conversion and 50 mg enzyme for cassava waste with 64.70% conversion. The highest amount was obtained for producing S. cerevisiae by adding 4.75 g peptone to all samples. The optimum number of cells was obtained at 1.61 x 108 colonies at t = 48 hours for arrowroot waste and 8.55 x 107 colonies at t = 48 hours for cassava waste. For β-glucan production, the highest number was obtained by using 3.99 g of peptone for cassava waste with a yield of 1.20% and by using 4.75 g of peptone for arrowroot waste with a yield of 1.23%. For β-glucan pellet, the highest number was 1.77 g L-1 (0.18 % b/v) from cassava waste medium and 1.91 g L-1 (0.19% b/v) from arrowroot waste. Mutant cells in the Yeast Extract–Peptone–Glycerol (YPG) medium produced 6.56 g L-1 (0.66% b/v) β-glucan pellet, while wild-type cells in the similar medium produced 1.84 g L-1 (0.18% b/v).

Synthesis and Biological Activity Evaluations of Green ZnO-Decorated Acid-Activated Bentonite-Mediated Curcumin Extract (ZnO@CU/BE) as Antioxidant and Antidiabetic Agents

Green ZnO-decorated acid-activated bentonite-mediated curcumin extract (ZnO@CU/BE) was prepared as a multifunctional antioxidant and antidiabetic agent based on the extract of curcumin, which was used as a reducing and capping reagent. ZnO@CU/BE showed notably enhanced antioxidant properties against nitric oxide (88.6 ± 1.58%), 1,1-diphenyl-2-picrylhydrazil (90.2 ± 1.76%), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (87.3 ± 1.61%), and superoxide (39.5 ± 1.12%) radicals. These percentages are higher than the reported values of ascorbic acid as a standard and the integrated components of the structure (CU, BE/CU, and ZnO). This signifies the impact of the bentonite substrate on enhancing the solubility, stability, dispersion, and release rate of the intercalated curcumin-based phytochemicals, in addition to enhancing the exposure interface of ZnO nanoparticles. Therefore, effective antidiabetic properties were observed, with significant inhibition effects on porcine pancreatic α-amylase (76.8 ± 1.87%), murine pancreatic α-amylase (56.5 ± 1.67%), pancreatic α-glucosidase (96.5 ± 1.07%), murine intestinal α-glucosidase (92.5 ± 1.10%), and amyloglucosidase (93.7 ± 1.55%) enzymes. These values are higher than those determined using commercial miglitol and are close to the values measured using acarbose. Hence, the structure can be applied as an antioxidant and antidiabetic agent.

Influence of amyloglucosidase, glucose oxidase, and transglutaminase on the technological quality of gluten‐free bread

AbstractBackground and ObjectivesThe main purpose of the present investigation was to evaluate the effects of the commercial enzymes amyloglucosidase, glucose oxidase, and transglutaminase on the technological quality of a gluten‐free bread based on cornstarch, rice flour, and buckwheat flour. Gluten‐free bread was analyzed for baking loss, bread central slice height, specific volume, textural properties, porosity, and pore size.FindingsGlucose oxidase and transglutaminase provided the lowest values of baking loss (7.16% and 6.38%, respectively) compared with the control (8.56%). Amyloglucosidase resulted in bread with specific volume three times greater (2.55 ml/g) than the control (0.9 ml/g). Transglutaminase provided a 73% decrease in crumb chewiness compared with the control and resulted in bread with small pores.ConclusionThe application of 15 g/kg of flour amyloglucosidase, 7.5 g/kg of flour glucose oxidase, and 0.25 g/100 kg of flour transglutaminase improved the overall technological quality of the developed gluten‐free bread.Significance and NoveltyThe results obtained showed that industrial enzymes can improve the technological quality—texture and crumb parameters—of a gluten‐free bread made from a complete formulation containing food additives, and buckwheat flour as a protein source.

Biocompatible poly(galacturonic acid) micro/nanogels with controllable degradation via tunable chemical crosslinking

Here, one-pot labor-less preparation of two different polygalacturonic acid (PGA) micro/nanogel formulations, PGA-1 and PGA-2, by respectively crosslinking the PGA chains with divinyl sulfone (DVS) and trimethylolpropane triglycidyl ether (TMPGDE) were reported. Various crosslinker ratios, 2.5, 10, 50, and 100% were used for both crosslinkers to demonstrate the tunability of their degradation properties. The PGA micro/nanogels were found spherical-shaped porous particles in 0.5–5.0 μm size range by SEM. The hydrolytic degradation and stability of PGA micro/nanogels in pH 1.0, 7.4, and 9.0 buffer solutions can be controlled by changing the degree of crosslinking. Accordingly, 32 ± 8% and 36 ± 2% weight losses were attained for PGA-1-10% and PGA-2-10% micro/nanogels at pH 1, respectively, and 46 ± 6%, and 68 ± 6% degradations were determined at pH 7.4 within 4 weeks. However, no degradation was observed for both PGA-based micro/nanogel formulations prepared at 25% and 100% crosslinker ratios at all pH conditions. All PGA-based micro/nanogels were totally degraded within 7–10 days at pH 9.0. In the presence of pectinase and amyloglucosidase enzymes, all formulations of PGA micro/nanogels showed more than 80% degradation within 12 h. Furthermore, both PGA formulations showed no significant cytotoxicity against L929 fibroblast cells with 90% and above cell viability up to 250 mg/mL concentrations.

Evaluation of Enzymatic Phenolic Extract from Garden Cress Seed Meal against Aflatoxigenic Fungi Isolated from Eggplant fruits

AbstractNatural products, like phenolic compounds from plant sources, exhibited antifungal activity and other biological activities. The current work aimed at studying the effect of phenolic compounds produced via enzymatic extraction from garden cress seed meal on some aflatoxins producing fungi isolated from the Eggplant fruits. In this elucidation, the chemical composition, minerals content and protein isolate of garden cress meal were investigated. Various enzymes (protease, cellulase, amyloglucosidase and their mixture) were used in the extraction of phenolic compounds with different concentrations. The antioxidant activities of all phenolic extracts were assisted. The polyphenolic compounds were defined by HPLC. Amino acid profile of the prepared protein isolate was also determined. On the other hand, six samples of Eggplant (10 of each) from two different locations were analyzed for mycological examination and aflatoxins association. The antifungal activity of phenolic extracts was measured by linear growth method of aflatoxigenic fungi. The results showed that a mixture of protease, cellulase, and amyloglucosidase enzymes with equal ratios exhibited major phenolic compounds (15.97mg/g) and also high antioxidant activities. The enzymatic phenolic extracts with different concentrations (10 and 20%) had a significant antifungal activity against aflatoxigenic fungi and other tested fungi. The highest growth inhibition of aflatoxigenic fungi was detected with A. parasiticus (55.82% at 20% conc.), while A. flavus detected less growth inhibition which recorded 40.54% at 20% conc. It could be concluded that garden cress phenolic extract is effective against some aflatoxigenic fungi.

Unfilterable Beer Haze Part I: The Investigation of an India Pale Ale Haze

The nature of undesirable and unfilterable haze particles observed by craft breweries remains nebulous and presents a challenge when the aim is the production of bright beer. A commercial beer was studied in which the brewery had sporadically encountered unfilterable haze. In this study, it was hypothesized that unfilterable haze particles were formed due to increased concentrations of proteins, polyphenols, and/or beta-glucans. Samples of a high haze and low haze India Pale Ale were degassed and digested with enzymes amyloglucosidase, pepsin, and UltraFlo Max (NovozymesTM). Additionally, the protein, polyphenol, and beta-glucan content of each sample was measured. When comparing protein, polyphenol, and beta-glucan concentrations substantial differences between high haze and low haze protein concentrations were observed. Due to the unfilterable nature of these hazes, combined with experimental findings, it was hypothesized that yeast cell-wall proteins were responsible for this haze. Understanding of the source of these hazes offers brewers the opportunity to mitigate against their formation by adjusting brewing practices.

In vitro α amylase and amyloglucosidase inhibitory activities of selected underutilized cereals, yams and root crops

Diabetes is one of the most challenging global health problems. Currently, reducing postprandial blood glucose concentration by inhibiting carbohydrate hydrolyzing enzymes is recognized as an effective treatment against diabetes. In this study, in vitro α-amylase and amyloglucosidase inhibitory effect of selected, underutilized and locally grown cereals (P. miliaceum, P. scrobiculatum and S. italica), yams (D. alata and D. esculenta) and root crops (L. spinosa and N. nucifera) were evaluated related to their dietary fiber contents. Results showed that the inhibitory effect of selected food crops has a positive correlation with their dietary fiber contents. L. spinosa with higher dietary fiber content generally had higher α-amylase (78.0%) and amyloglucosidase (71.28%) enzyme inhibitory percentages among yams and root crops. Significantly highest (p<0.05) dietary fiber content was in S. italic among three cereal varieties and it showed the highest inhibition activity against α-amylase (67.8%) and amyloglucosidase (59.40%) activity. These tested food crops are considerable sources of dietary fiber and are having α-amylase and amyloglucosidase enzyme inhibitory actions against starch hydrolysis.

NMR visibility of deuterium-labeled liver glycogen in vivo.

Deuterium metabolic imaging (DMI) combined with [6,6'-2 H2 ]-glucose has the potential to detect glycogen synthesis in the liver. However, the similar chemical shifts of [6,6'-2 H2 ]-glucose and [6,6'-2 H2 ]-glycogen in the 2 H NMR spectrum make unambiguous detection and separation difficult in vivo, in contrast to comparable approaches using 13 C MRS. Here the NMR visibility of 2 H-labeled glycogen is investigated to better understand its potential contribution to the observed signal in liver following administration of [6,6'-2 H2 ]-glucose. Mice were provided drinking water containing 2 H-labeled glucose. High-resolution NMR analyses was performed of isolated liver glycogen in solution, before and after the addition of the glucose-releasing enzyme amyloglucosidase. 2 H-labeled glycogen was barely detectable in solution using 2 H NMR because of the very short T2 (<2 ms) of 2 H-labeled glycogen, giving a spectral line width that is more than five times as broad as that of 13 C-labeled glycogen (T2 = ~10 ms). 2 H-labeled glycogen is not detectable with 2 H MRS(I) under in vivo conditions, leaving 13 C MRS as the preferred technique for in vivo detection of glycogen.

Enzymatic hydrolysis behavior on malt bagasse for fermentative sugar disposal in thermostatic and ultrasonic bath

AbstractThis study evaluated the effect of enzymatic hydrolysis on malt bagasse for fermentative sugar extraction in thermostatic and ultrasonic bath. The enzymatic reaction was performed using cellulase, α‐amylase, and amyloglucosidase (in separate and combined) on malt bagasse to analyze the hydrolysis effect. For this, a central composite rotational design was applied to evaluate the effect of solid:liquid (malt bagasse w/v) versus enzymatic concentration, considering cellulase, α‐amylase, and amyloglucosidase enzymes in mix solution, on fermentable sugars liberation. Then the kinetic fermentative sugars liberation was evaluated in a hydrolysis reaction using cellulase, α‐amylase, and amyloglucosidase (in separate and combined) after exposure in thermostatic and ultrasonic bath. From enzymatic mix, the maximum total reducing sugar (TRS) yield was 408.8 and 219.9 mg·g−1 in thermostatic and in ultrasound bath, respectively. Kinetic studies showed a TRS variation of 6 to 7 g·L−1 for all enzymes. Amyloglucosidase was more promising in assimilation of malt bagasse, responsible for 43% of sugar releasing. Briefly, a low‐cost procedure using thermostatic bath improved the hydrolysis reaction. The results from the experiments present a new application where malt bagasse can be employed showing the potential of this brewing industry residue in fomenting processes, as bioethanol production.

Concentration of Exopolysaccharides (EPS) Produced from Fermentation of Hydrolysate Biomass of Tuni Sagoo (Metroxylon sp.) Starch by Lactobacillus plantarum FU-0811 in Semi Pilot Scale using Nanofiltration

Nanofiltration (NF) system is one of the concentration process step to recover exopolysaccharides (EPS) concentrate (retentate) as food aditive (thickener, stabilizer and emultion). Feed was biomass containing EPS as a result of growth of Lactobacillus plantarum FU-0811 culture under 37 °C for 72 hours in semi pilot scale (20 L). Biomass was a growth media containing sagoo sugar as a result of step enzymatic hydrolysis on tuni sagoo (Metroxylon sp.) starch using commercial α–Amylase and Amyloglucosidase (AMG) enzymes and other active compounds. Concentration process was conducted by pump motor frequency of 20 Hz, room temperature, and pressure of 10, 15 and 20 bar for 0, 30, 60, 90 and 120 minutes. Result of experimental work showed that NF system has potential use to concentrate biomass containing higher composition than that permeate. Based on optimum EPS, NF system that results a successfully separation of EPS with rejection of 95.24 % was reached at pressure of 20 bar and 60 minutes to retain EPS in concentrate (retentate) of 2.454 % (dry weight) and freely pass in permeate of 0.0097 % (dry weight) with permeate flux value 37.5 L/m2.hour. In this optimum process condition, NF system was able to increase of EPS in retentate of 56.46 % from prior to process (feed) and after process concentration.

The changes of starch and sugar on fermented of mixture of cassava and sweet potatoes using local tape ragi

The aims of this study is to determine the change of starch and sugar content on cassava roots and sweet potato substrates through local “Tape Ragi” fermentation. The type of research is experiment with solid substrate fermentation method. The cassava roots and sweet potato mixture substrate is made with variation of concentration 1:0; 1:1; 1:3; 3:1 and 0:1. The tape ragi used is obtained from the traditional market of Bone regency of South Sulawesi province which is the result of selection in previous research. Analysis of starch content on products using enzymatic methods. The principle of analysis by such methods is starch extracted by dimethyl sulfoxide and acid, hydrolyzed by enzyme amyloglucosidase into sugar. The sugar content is determined by the determination of total sugar, and the starch content is 0.9 times the sugar content. The results of this study shows that the fermented mixture of cassava roots and sweet potatoes using local tape ragi B causes changes in starch and sugar levels. Level of starch on cassava roots subtract treatment (K), mixture of cassava roots and sweet potato with ratio 1: 1 (K1J1) and cassava roots and sweet potato mixture with ratio 3: 1 (K3: J1) decreased. The treatment of sweet potato substrate (J) and cassava roots mixture and sweet potato mixture with ratio of 1: 3 (K1J3) actually increased to 24.84% from 22.78% before fermentation and 33.57% from 27.48% before fermentation. All variations of the substrate treatment experienced a change in the increase in the amount of sugar content after fermentation using local tape ragi.

FeedER: a feedback-regulated enzyme-based slow-release system for fed-batch cultivation in microtiter plates

With the advent of modern genetic engineering methods, microcultivation systems have become increasingly important tools for accelerated strain phenotyping and bioprocess engineering. While these systems offer sophisticated capabilities to screen batch processes, they lack the ability to realize fed-batch processes, which are used more frequently in industrial bioprocessing. In this study, a novel approach to realize a feedback-regulated enzyme-based slow-release system (FeedER), allowing exponential fed-batch for microscale cultivations, was realized by extending our existing Mini Pilot Plant technology with a customized process control system. By continuously comparing the experimental growth rates with predefined set points, the automated dosage of Amyloglucosidase enzyme for the cleavage of dextrin polymers into d-glucose monomers is triggered. As a prerequisite for stable fed-batch operation, a constant pH is maintained by automated addition of ammonium hydroxide. We show the successful application of FeedER to study fed-batch growth of different industrial model organisms including Corynebacterium glutamicum, Pichia pastoris, and Escherichia coli. Moreover, the comparative analysis of a C. glutamicum GFP producer strain, cultivated under microscale batch and fed-batch conditions, revealed two times higher product yields under slow growing fed-batch operation. In summary, FeedER enables to run 48 parallel fed-batch experiments in an automated and miniaturized manner, and thereby accelerates industrial bioprocess development at the screening stage.

Inhibitor Effect (Lipid and Protein) in Starch Hydrolysis to Produce Glucose by using Amyloglucosidase

Microalgae contains approximately 24 % of starch which is potential for bioethanol feedstock by enzymatic hydrolysis. The problem is that starch in microalgae is accumulated with protein and lipid, while the interaction of starch-protein and starch-lipid might inhibit enzymatic hydrolysis of starch. Native starch, isolate protein and palmitic acid are used to investigate the interaction effects of starch-protein and starch-lipid in microalgae. This study aimed to investigate effects of protein and lipid concentration (1:0, 1:0.05, 1:0.1, 1:0.25, 1:0.5, 1:1) (w/w) added into native starch hydrolysis by amyloglucosidase enzyme were incubated at 45°C for 3 hours. The product of hydrolyzed was determined as glucose with spectrophotometer UV-Vis at 540 nm. The result shows that the increasing of protein and lipid concentration added into starch granule will significantly (P<0.05) decrease concentration of glucose product. The kinetic parameters are evaluated by Michaelis-Menten models for uncompetitive inhibition.

Purification and Characterization of Amyloglucosidase Enzyme from the Thermophilic &lt;i&gt;Endomycopsis fibuligera&lt;/i&gt; Using Sago Starch as a Substrate

An investigation on purification and characterization of amyloglucosidase enzyme from Endomycopsis fibuligera by fermentation of sago starch has been carried out. This enzyme is inductive and can be produced by fermenting sago starch in a medium containing E. fibuligera. Crude enzyme was obtained by centrifuging the medium cultures containing E. fibuligera at 6,000 rpm for 20 min and then adding with 0.15 M acetate buffer (pH 5.0). Enzyme activity was determined using Somogyi-Nelson method by quantifying the released glucose from amyloglucosidase catalysis of starch (0.2%) as substrate. Prepurification process was conducted by ammonium sulphate fractionation and it showed that the ammonium sulphate fractionation with the degree of saturation of 40-60% produced a maximum activity of enzyme. Purification by DEAE-Cellulose and Sephadex G-75 column chromatography produced three and one fractions with purifity 17.4 and 22.5 times, respectively, compared to the crude extract enzyme. Characterization of this enzyme showed the optimum condition at pH 5.0 and 55 °C with 0.2% starch as substrate. The amyloglucosidase activities was strongly increased by addition of Co2+ and Mn2+ ions, whereas the activities were weakly decreased by addition of K+, Mg2+, and Fe3+ ions.