Starch Adsorption Research Articles

Moisture Sorption Isotherms of Polydextrose and Its Gelling Efficiency in Inhibiting the Retrogradation of Rice Starch.

As an anti-staling agent in bread, the desorption isotherm of polydextrose has not been studied due to a very long equilibrium time. The adsorption and desorption isotherms of five Chinese polydextrose products were measured in the range of 0.1-0.9 aw and 20-35 °C by a dynamic moisture sorption analyzer. The results show that the shape of adsorption and desorption isotherms was similar to that of amorphous lactose. In the range of 0.1-0.8 aw, the hysteresis between desorption and adsorption of polydextrose was significant. The sorption isotherms of polydextrose can be fitted by seven commonly used models, and our developed seven-parameter polynomial, the adsorption equations of generalized D'Arcy and Watt (GDW) and Ferro-Fontan, and desorption equations of polynomial and Peleg, performed well in the range of 0.1-0.9 aw. The hysteresis curves of polydextrose at four temperatures quickly decreased with aw increase at aw ˂ 0.5, andthereafter slowly decreased when aw ≥ 0.5. The polynomial fitting hysteresis curves of polydextrose were divided into three regions: ˂0.2, 0.2-0.7, and 0.71-0.9 aw. The addition of 0-10% polydextrose to rice starch decreased the surface adsorption and bulk absorption during the adsorption and desorption of rice starch, while it increased the water adsorption value at aw ≥ 0.7 due to polydextrose dissolution. DSC analysis showed that polydextrose as a gelling agent inhibited the retrogradation of rice starch, which could be used to maintain the quality of cooked rice.

Selective adsorption of soluble starch on the cassiterite surface for effective flotation separation of scheelite from cassiterite

Tungsten and tin are important strategic resources. Scheelite and cassiterite have similar physical and chemical properties and face the challenge of flotation separation. This study proposes soluble starch (SS) as an effective depressant for the flotation separation of scheelite from cassiterite. The depression mechanism of SS was investigated using micro-flotation, zeta potential, total organic carbon, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectroscopy. SS exhibited a good selective depressive effect on cassiterite and was able to efficiently separate scheelite from cassiterite. The results of artificial mixed mineral test showed that the recovery of scheelite and cassiterite were 79.35 % and 9.48 %, respectively and the grade were 70.15 % and 8.11 %, respectively at pH 10. The macromolecular organic depressant SS has abundant hydrophilic groups, such as hydroxyl groups, which cause the material to stably adsorb on Sn active sites on the surface of cassiterite and hinder the adsorption of the collector sodium oleate (NaOL, C17H33CO2Na). The selective adsorption of SS on the surface of cassiterite results in efficient flotation separation of the two minerals.

Effect of Sodium Hexametaphosphate on Flotation of Quartz and Hematite with Starch/Etheramine in the Presence of Ca and Mg Ions

ABSTRACT The aim of this study was to evaluate the effect of sodium hexametaphosphate (SHMP), a complexing reagent for Ca and Mg ions, on iron ore reverse cationic flotation. Quartz and hematite samples contaminated with both Ca and Mg were subjected to microflotation assays at pH 10.5 with starch and etheramine, which showed that SHMP did not provide selectivity in the separation of these minerals. Zeta potential measurements, Fourier transform infrared spectroscopy of quartz and hematite without and with the studied reagents (starch, amine, SHMP, CaCl2/MgCl2) and published studies in the literature indicated that although the HMP anions removed the Ca and Mg ions from both minerals, it also formed complexes with the Fe3+ ions on the hematite surface, which prevented subsequent adsorption of starch and consequently decreased the selectivity for reverse flotation of iron ore.

Preparation polymer-grafted magnetic starch adsorption material St/Fe3O4-g-p(GMA-r-HEMA) used for removal of heavy metals

Heavy metal ion (Cu(II)) wastewater will do great harm to human body and environment, and the adsorption materials used in traditional adsorption methods are easy to hydrolyze, resulting in secondary pollution to water. In this paper, an adsorption material poly(glycidyl methacrylate-random-hydroxyethyl methacrylate) grafted ferric oxide@starch (St/Fe3O4-g-p(GMA-r-HEMA)) was prepared, which had epoxy and hydroxyl group, easy to produce crosslinking, reduce the sensitivity of starch to pH and prevent hydrolysis. Infrared spectroscopy (FTIR), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and magnetometer (VSM) were used to characterize the structure and morphology of the adsorbent. The adsorption properties of the adsorbent for removal of Cu(II) ions were studied via changing the experimental conditions, including the amount of adsorbent, Cu(II) ions solution concentration, pH value, adsorption time, adsorption temperature and so on. Under the optimal adsorption conditions of pH value 7, initial Cu(II) concentration 20 mg/L and adsorption time 160 min, the maximum unit adsorption capacity of St/Fe3O4-g-p(GMA-r-HEMA) was 94.15 mg/g, and the adsorption performance was good. The adsorption process followed Langmuirm model and second-order kinetic model, and was dominated by chemisorption. The thermodynamic model showed that the adsorption process of St/Fe3O4-g-p(GMA-r-HEMA) was endothermic. After 8 adsorption cycles, 93.5% of the first adsorption effect can still be retained, and the renewable performance had been improved.

Insight on the mechanism of hexagonal pyrrhotite depression by starch during flotation

Polysaccharides such as gelatinized starch have been largely employed to depress specific minerals during froth flotation. In this study, two samples of caustic gelatinized starch (paste starches) with different molecular weights (MW) were used as depressants for hexagonal pyrrhotite. There is an increasing interest in finding more environmentally friendly strategies to depress hexagonal pyrrhotite since this mineral is one major gangue minerals in nickeferrous ore deposits, for instance. The mechanism of adsorption of paste starches on hexagonal pyrrhotite was evaluated by different techniques. Equilibrium adsorption tests suggested that the adsorption is dependent on the depressant molecular weight if it is used in high concentrations. The sequence of conditioning also showed to be relevant. Pre-adsorbed collector highly influenced the adsorption of higher MW paste starch. Langmuir and Brunauer–Emmett–Teller (BET) model fittings of adsorption data in combination with Quartz Crystal Microbalance with Dissipation (QCM-D) results demonstrated a looser packing density of the higher MW paste starch. This conformation provides more room for water molecules within this depressant’s chains. Since trapped water molecules may generate a repulsive hydration force to air bubbles near the mineral surface, pyrrhotite conditioned with the high MW paste starch showed a lower flotation recovery. Higher hydration levels of the higher MW paste starch were also proven by Atomic Force Microscopy (AFM) tests, and indirectly quantified in the contact angle measurements (Washburn method). Although the higher MW paste starch adsorbs less, this depressant still provides a higher surface wettability. This study has reinforced the importance in considering the molecular size of a polysaccharide for sulfide mineral depression.

Performance and mechanism of starch-based porous carbon capture of Cr(VI) from water

Cr(VI) pollution has seriously affected the survival of biological organisms and humans, so reducing the harm of Cr(VI) pollution is a significant scientific goal. Natural starch exhibits a low adsorption capacity for Cr(VI); thus, physical or chemical modification is needed to improve the adsorption and regeneration performance of starch. In this study, a novel starch-based porous carbon (SPC) was prepared to remove Cr(VI) from water by using soluble starch as a raw material. The characterization results show that the SPC shows a ratio surface area of 1325.39 m2/g. Kinetics suggest that the adsorption of Cr(VI) on SPC is dominated by chemisorption. The isotherm data demonstrated that the adsorption of Cr(VI) by SPC adhered to the Freundlich model. SPC exhibits a multimolecular layer adsorption structure, and the highest amount of adsorbed Cr(VI) in SPC was 777.89 mg/g (25 °C). Ion competition experiments show that SPC exhibits significant selectivity for Cr(VI) adsorption. In addition, the adsorption cycle experiment shows that SPC maintains a 63 % removal rate after 7 cycles. In this study, starch was transformed into high-quality adsorbent materials by hydrothermal and activation strategies, offering a new innovation for the optimization of starch-based adsorbents.

Investigation into starch adsorption on hematite and quartz in flotation: Role of starch molecular structure

Various starches have been used as depressants in reverse flotation of iron ores. To date, the effect of molecular structures of starches on the depressing behavior is still not clear using simulation study. In this study, three starches with different ratios of amylose/amylopectin on the molecule (Normal Starch, Waxy Starch and Gelose 50) were used to study their depressing ability on the flotation of hematite and quartz. Microflotation, Zeta potential measurement, XPS analysis and AFM measurement were performed to investigate the interaction between the two minerals and the three starches. It was found that chemisorption occurred between hematite and the starches, while only hydrogen bonding was observed between quartz and the starches. In addition, it was obtained that the chemisorption strength between the starches and hematite under alkaline condition fell in the order: Waxy Starch > Normal Starch > Gelose 50, which was closely related to the ratios of amylose/amylopectin. The underlying mechanism for the different chemisorption strength was revealed via computational chemistry analysis. It is believed that the outcomes of this work could optimize the development of starch-based depressants in iron ore flotation.

Characterization and adsorption-release property of fermented porous starch as well as its bioactivity protection for guava leaf polyphenols

Porous starch has been considered an effective delivery system for bioactive substances such as polyphenols. However, conventional preparation methods of porous starch are complex, costly and easily cause pollution, which limits large-scale production. To explore a better method for the clean production of porous starch, this study prepared porous starch by fermentation with Monascus anka GIM 3.592 and constructed a delivery system of guava leaf polyphenols based on fermented porous starch (FPS). The results show that the surface of FPS was porous, and the specific surface area of FPS was nearly twice that of native starch. The adsorption capacity of fermented starch was increased by 217.18% compared with native starch and slightly higher than that of commercial porous starch. The FT-IR intensity ratio of the 995/1022 and 1047/1022 bands and relative crystallinity increased, while the particle size of fermented starch decreased. The adsorption depended on hydrogen bonds, and the adsorption of fermented starch to quercetin was stronger than that of other flavonoid glycosides from guava leaf polyphenols, where the adsorption rate reached 63.74% ± 0.28%. Furthermore, antioxidant activity protection and sustained release of the polyphenol-starch complex were achieved. This study provides a promising strategy to prepare porous starch and construct a polyphenol delivery system.

Cloning and characterization of thermostable amylopullulanase TbbApu and its C-terminal truncated variants with enhanced activity in organic solvents

Bifunctional debranching-enzyme amylopullulanases belong to the glycoside hydrolases (GHs) family and catalyze both the hydrolysis of α-1,4 and α-1,6 glycosidic bonds in starch, pullulan, amylopectin and glycogen polysaccharides. Among these, especially thermostable ones are essential in starch processing applications. In this study, we focused to elucidate the complete sequence of the apu gene and the role of C-term domains on biochemical properties and enzyme activity of Thermoanaerobacter brockii brockii amylopullulanase (TbbApu). After the gene sequence was defined, C- term truncated variants were constructed. The most suitable host organism and expression vector were determined as E. coli BL21(DE3) and pET-28a(+) depending on the highest yield/biomass ratio for recombinant production of all constructs. It was seen that the expression yield increased approximately threefold in the case of the SH3 region truncation. In the biochemical characterization, TbbApu and its truncated variants exhibited maximum activity at 70 °C and 75 °C for pullulan and starch hydrolysis respectively, and the optimum pH of TbbApu were 6.5 and 6 for truncated variants. Moreover, hydrolysis activities of all recombinant enzymes were enhanced by Mn2+, Co2+ and Cu2+, detergents, and almost all organic solvents; except butanol, DMF and DMSO. All recombinant amylopullulanases remained 80% stable up to 80 °C in the wide range of pH and also retained > 85% stability in the presence of defined volatile organic solvents. No significant difference was observed between the raw starch adsorption capacity and the specific activity of the three variants. These results indicated that the C-terminal regions of TbbApu are non-essential for the enzyme activity, stability and substrate binding capacity; furthermore, hexane and acetone organic solvents enhanced both pullulanase and α-amylase activity of these enzymes, interestingly. With these features, TbbApu and its truncated variants are distinguished from other thermophilic amylopullulanases and also make them promising candidates for industrial use.

Adsorption and depression effects of native starch, oxidized starch, and dextrin on graphite

• Interactions of starch-based depressants with graphite characterised. • Oxidised starches with high ratio of –C=O to –COOH are effective depressants. • Hydrophobic interaction mechanism proposed based on negative effect of -COOH beyond a threshold • <15% surface coverage required for effective depression with oxidised starches. Carbon is a common gangue , often associated with base metal ores. The hydrophobicity of carbon causes interaction with air-bubbles during flotation , and results in carbon contamination of concentrate and grade reduction of base metals. Therefore, selective separation of carbon is important during froth flotation processing. Native and modified starch have been recommended to depress carbon during flotation, however neither the mechanism of interaction nor the efficiency of carbon depression by different forms of starch is currently clear. Using two sets of oxidized starches (native wheat starch oxidized by 2, 5 and 10% concentration of either H 2 O 2 or NaOCl at pH 4) and comparing them with dextrin and native wheat starch (NWS), the mechanism of depression of graphite (a carbon exemplar) was investigated through adsorption isotherm and micro-flotation experiments as a function of starch functional group content, molecular size distribution and surface coverage estimation. Efficiency of depression of graphite by oxidized starches was favoured by a high proportion of substituted -C = O compared to –COOH groups. Increasing proportion of –COOH beyond a threshold negatively impacted on depression of graphite. Dextrin had an intermediate efficiency to depress graphite whereas NWS was poor at low dosage range but with high dosage showed good depression. A low estimated surface coverage (<22%) by different starch polymers was enough to cause effective depression of graphite. The data are consistent with depression of graphite by starches being guided by a hydrophobic interaction mechanism. The results also demonstrate that controlled oxidation modification can be used to tailor-make starch for graphite (carbon) depression.

Starch adsorption on hematite surfaces: Evidence of the adsorption mechanism dependence on the surface orientation

In this study, the adsorption mechanism of amylopectin molecules on the hematite (112¯0), (11¯00) and (0001) single-crystal surfaces were investigated by surface-sensitive techniques. Our results show evidence of preferential adsorption on the hematite surface planes in the order of (112¯0) > (11¯00) > (0001). Based on these findings, we propose that distinct singly and triply coordinated oxygen atoms on the surface react in pairs by a multisite complexation mechanism to promote the attachment of amylopectin molecules. These results demonstrate the pivotal role of the exposed hematite surface structure–reactivity relationship in starch adsorption and the possible causes of inefficiencies in industrial flotation processes, as well as biomedical and environmentally friendly technologies based on hematite nanoparticles.

Effect of frying on total oil adsorption of freeze-thawed and raw starches

The effect of frying on the total oil adsorption (TOA) of freeze-thawed corn starch (F-FC), wheat starch (F-FW), and tapioca starch (F-FT) was studied compared with their raw versions. Compared with fried raw corn starch (F–C), wheat starch (F–W), and tapioca starch (F-T), the TOA of corresponding fried freeze-thawed starches were significantly reduced by 8.47%, 10.64%, and 3.83%, respectively. After frying, as the amylose content increased by 1.24%, 0.65%, and 0.58%, the matrix oil adsorption (MOA), which is closely related to the amylose content, also increased slightly by 0.32%, 0.20%, and 0.72%. However, the increase in MOA has little impact on the reduction of TOA. The Fourier-transform infrared spectroscopy results indicated a reduction in the lipophilic groups of freeze-thawed starches upon frying, which could increase the oleophobicity of starches. The specific surface areas of F-FC, F-FW, and F-FT were reduced by 16.13 m2/kg, 33.57 m2/kg, and 8.17 m2/kg, respectively, which would reduce TOA. Therefore, the freeze-thawed starches adsorbed less total oil than raw starches after frying. X-ray diffraction results showed that all the samples were still A-type, but the crystallinity of freeze-thawed starches decreased by 1.47%, 2.80%, and 0.73% after frying.

Specifically Adsorbed Ions in the Reverse Cationic Flotation of Iron Ore

ABSTRACT Although extensive research has been conducted on the effect of water chemistry in flotation, no single study exists which describes the effect of calcium and magnesium on the adsorption of starch onto the hematite in iron ore flotation. In this work flotation, entrainment, zeta potential, and settling tests were performed to determine the differing impact of calcium and magnesium in iron ore flotation. Results showed that magnesium is more detrimental to the flotation process at far lower concentrations than calcium. Performing flotation with 45 ppm of calcium resulted in a comparable impact on the process as performing flotation with 7 ppm of magnesium. While calcium promotes the adsorption of starch onto the hematite and reduces entrainment, past an optimal dosage magnesium is promoting the adsorption of starch to everything in solution causing low grades and recoveries. It was found that the starch adsorption onto the hematite is strongly impacted by the presence of magnesium, suggesting that starch is collecting the magnesium and self-flocculating prior to adsorption onto the hematite. Thus, the presence of magnesium can significantly reduce the flotation performance far more than what would be expected from calcium.

Preparation of Carboxylic Acid Grafted Starch Adsorption Resin and Its Dye Removal Performance

Preparation of Carboxylic Acid Grafted Starch Adsorption Resin and Its Dye Removal Performance

Adsorption of α-amylase and Starch on Porous Zinc Oxide Nanosheet: Biophysical Study

Engineered biocatalyst and its desired products using nanotechnology has intensified the research in food industries. Zinc oxide (ZnO) nanosheet is designed and prepared; the characterization studies include surface plasmon resonance peak (364 nm), X-ray diffraction pattern determined crystallite size (25 nm), and transmission electron microscopy confirms the porous surface nature. Atomic force microscopy showed substrate and enzyme adsorbed on ZnO nanosheets. The zeta potential of ZnO nanosheet (−41.9 mV) whereas α-amylase bound with ZnO nanosheets (−32.8 mV), and starch bound with ZnO nanosheets (−28.7 mV) was analyzed using dynamic light scattering. The circular dichroism spectra displayed α-helix in native amylase at optimum concentration 54.70% compared to the adsorbed α-amylase with ZnO nanosheet that showed 37%. Freundlich isotherm model revealed multilayer adsorption behavior of α-amylase onto porous ZnO nanosheet. Enzyme kinetics study presents alteration in Michaelis–Menten constant (Km) and maximum velocity (Vmax), the α-amylase bound with porous ZnO nanosheet showed a reduction in Km and Vmax. The substrate and enzyme adsorbed together on porous ZnO nanosheet exhibited increased Km (27.77 μM), whereas Vmax (2.85 μM) remains unchanged. Moreover, α-amylase once modified at optimum pH (5.8) and temperature (52 °C), produces less maltose than α-amylase adsorbed on ZnO nanosheet, which indicates higher maltose production. In this study, ZnO nanosheet enzyme catalytic system was created, wherein enzymatic reaction shifted to different pH and temperature other than optimum conditions. All these findings suggest that careful attention to the enzyme adsorption profiles can contribute to industrial applications.

Effects of α-amylase and glucoamylase on the characterization and function of maize porous starches

To overcome the limited surface area of starch and improve the adsorption capacity of starch, porous starch has been widely produced in various fields. In this study, the different enzyme activities of α-amylase (AM), glucoamylase (GAM), and mixed enzyme (ME) were used to prepare different types of porous maize starch, and the microstructure, particle morphology, adsorption, and gelatinization characteristics of the porous starch were studied. Scanning electron microscopy showed porous structures with diverse pore size distribution and pore area depending on the enzyme type and its activities; AM produced the largest holes, GAM produced the deepest holes, and ME produced large and deep holes. Adsorptive capacity was significantly affected by enzymatic modification being greater influenced by GAM. The porous starches had higher relative crystallinity as deduced from X-ray diffraction and Fourier transform infrared spectroscopy. The MA-treated starch had higher solubility whereas swelling capacity, peak viscosity, final viscosity, breakdown, and setback of both treatments were decreased compared to the native starch. The results indicate porous maize starch can provide different functions according to the action pattern of enzymes. The type of enzyme and its enzyme activity can be used to produce the ideal cavity and pore size starch granules, which expands its application scope.

Enhancement of ��-Cyclodextrin Production and Fabrication of Edible Antimicrobial Films Incorporated with Clove Essential Oil/��-cyclodextrin Inclusion Complex

Edible films containing antimicrobial agents can be used as safe alternatives to preserve food products. Essential oils are well-recognized antimicrobials. However, their low water solubility, volatility and high sensitivity to oxygen and light limit their application in food preservation. These limitations could be overcome by embedding these essential oils in complexed product matrices exploiting the encapsulation efficiency of β-cyclodextrin. This study focused on the maximization of β-cyclodextrin production using cyclodextrin glucanotransferase (CGTase) and the evaluation of its encapsulation efficacy to fabricate edible antimicrobial films. Response surface methodology (RSM) was used to optimize CGTase production by Brevibacillus brevis AMI-2 isolated from mangrove sediments. This enzyme was partially purified using a starch adsorption method and entrapped in calcium alginate. Cyclodextrin produced by the immobilized enzyme was then confirmed using high performance thin layer chromatography, and its encapsulation efficiency was investigated. The clove oil/β-cyclodextrin inclusion complexes were prepared using the coprecipitation method, and incorporated into chitosan films, and subjected to antimicrobial testing. Results revealed that β-cyclodextrin was produced as a major product of the enzymatic reaction. In addition, the incorporation of clove oil/β-cyclodextrin inclusion complexes significantly increased the antimicrobial activity of chitosan films against Staphylococcus aureus, Staphylococcus epidermidis, Salmonella Typhimurium, Escherichia coli, and Candida albicans. In conclusion, B. brevis AMI-2 is a promising source for CGTase to synthesize β-cyclodextrin with considerable encapsulation efficiency. Further, the obtained results suggest that chitosan films containing clove oils encapsulated in β-cyclodextrin could serve as edible antimicrobial food-packaging materials to combat microbial contamination.

Predictive model based on Adaptive Neuro-Fuzzy Inference System for estimation of Cephalexin adsorption on the Octenyl Succinic Anhydride starch

The purpose of this study was to investigate the potential of an amphiphilic biopolymer to remove organic contaminants from aqueous solutions. The removal of Cephalexin antibiotic as model compound by adsorption using the Octenyl Succinic Anhydride starch (OSA starch) as amphiphilic polysaccharide was studied. The effects of various parameters such as contact time, pH, temperature and OSA starch dosage were investigated. Different adsorption isotherm models were tested, and it was found that, the best fit with the experimental data is provided by Langmuir and Redlich-Peterson models (R2 = 0.9638 and R2 = 0.9661 respectively). The maximum adsorption capacity was obtained is 0,9236 mg/g in optimal conditions (pH = 6, T = 25 °C and OSA starch initial concentration of 5 g/L). Pseudo-second order model has perfectly represented the kinetic data (R2 = 0.9932). On the other hand, an Adaptive Neuro-Fuzzy Inference System (ANFIS) was optimized for modeling the adsorption process by predicting the OSA starch adsorption capacity as well as the effect of the different parameters. The predicted values are very similar to the experimental results with coefficient of determination (R2) of 0.999 and Root Mean Square Error (RMSE) equal to 3.9 × 10−3. Furthermore, thermodynamic study showed the exothermic nature of Cephalexin adsorption on OSA starch.

AFM and DFT study of depression of hematite in oleate-starch-hematite flotation system

The depression of hematite in the reverse flotation system of oleate-starch-hematite was investigated at the atomic level by atomic force microscopy (AFM) combined with density functional theory (DFT). AFM imaging and cross-sectional imaging show that the adsorption configurations of oleate and starch on hematite were in shuttle and flake patterns, respectively, resulting in a greater adsorption thickness and adsorption area for starch than for oleate on the hematite surface. After functioned by starch, hematite was almost fully covered by starch so that there was no sufficient space for the adsorption of oleate. Corn starch was also detected aggregating fine hematite particles just like a flocculant. In the DFT study of the system, convergence tests were conducted to get the optimized hematite crystal geometry. The calculated interaction energies and Mulliken populations verified the favorable adsorption of oleate and starch on the hematite surface. Results indicated that covalent bonds formed between oleate and hematite, as well as between starch and hematite. However, in the oleate-starch-hematite system, the calculations showed that the distance between oleate and hematite in the presence of starch was too long to allow the adsorption of oleate. As for the water effect on the depression of hematite, the water molecules acted as a bridge between starch and the hematite surface by hydrogen bonds and were accompanied by chemical bonds between hematite surfaces and starch, which led to the depression of hematite. Therefore, in reverse flotation, oleate is hindered from adsorbing on the starch-covered hematite surface. The work presented here has profound implications for future studies of the depression of hematite, and may help solve the problem of screening and design of depressant of hematite.

Purification and biochemical characterization of extracellular glucoamylase from Paenibacillus amylolyticus strain.

In the present study, glucoamylase produced from a soil bacterium Paenibacillus amylolyticus NEO03 was cultured under submerged fermentation conditions. The extracellular enzyme was purified by starch adsorption chromatography and further by gel filtration, with 2.73-fold and recovery of 40.02%. The protein exhibited molecular mass of ∼66,000 Da as estimated by SDS-PAGE and depicted to be a monomer. The enzyme demonstrated optimum activity at pH range 6.0-7.0 and temperature range 30-40 °C. Glucoamylase was mostly activated by Mn2+ metal ions and depicted no dependency on Ca2+ ions. The enzyme preferentially hydrolyzed all the starch substrates. High substrate specificity was demonstrated towards soluble starch and kinetic values Km and Vmax were 2.84 mg/ml and 239.2 U/ml, respectively. The products of hydrolysis of soluble starch were detected by thin layer chromatography which showed only D -glucose, indicating a true glucoamylase. The secreted glucoamylase from P. amylolyticus strain possesses properties suitable for saccharification processes such as biofuel production.