scholarly journals Optimization of Culture Conditions for Some Identified Fungal Species and Stability Profile of α-Galactosidase Produced

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
A. S. Chauhan ◽  
N. Srivastava ◽  
H. K. Kehri ◽  
B. Sharma
Keyword(s):  
Enzyme Activity ◽  
Guar Gum ◽  
Enzyme Stability ◽  
Culture Conditions ◽  
Fungal Species ◽  
Agricultural Products ◽  
Rhizospheric Soil ◽  
Carbon Substrates ◽  
The Stability ◽  
Stability Results

Microbial α-galactosidase preparations have implications in medicine and in the modification of various agricultural products as well. In this paper, four isolated fungal strains such as AL-3, WF-3, WP-4 and CL-4 from rhizospheric soil identified as Penicillium glabrum (AL-3), Trichoderma evansii (WF-3), Lasiodiplodia theobromae (WP-4) and Penicillium flavus (CL-4) based on their morphology and microscopic examinations, are screened for their potential towards α-galactosidases production. The culture conditions have been optimized and supplemented with specific carbon substrates (1%, w/v) by using galactose-containing polysaccharides like guar gum (GG), soya casein (SC) and wheat straw (WS). All strains significantly released galactose from GG, showing maximum production of enzyme at 7th day of incubation in rotary shaker (120 rpm) that is 190.3, 174.5, 93.9 and 28.8 U/mL, respectively, followed by SC and WS. The enzyme activity was stable up to 7days at −20°C, then after it declines. This investigation reveals that AL-3 show optimum enzyme activity in guar gum media, whereas WF-3 exhibited greater enzyme stability. Results indicated that the secretion of proteins, enzyme and the stability of enzyme activity varied not only from one strain to another but also differed in their preferences of utilization of different substrates.

scholarly journals Studies on the production of glucose isomerase by Bacillus licheniformis

2015 ◽  
Vol 17 (3) ◽  
pp. 84-88 ◽  
Author(s):  
Ogbonnaya Nwokoro
Keyword(s):  
Enzyme Activity ◽  
Bacillus Licheniformis ◽  
Organic Nitrogen ◽  
Specific Activity ◽  
Inorganic Nitrogen ◽  
Glucose Isomerase ◽  
Culture Conditions ◽  
Enzyme Productivity ◽  
Carbon Substrates ◽  
Optimum Ph

Abstract This work reports the effects of some culture conditions on the production of glucose isomerase by Bacillus licheniformis. The bacterium was selected based on the release of 3.62 mg/mL fructose from the fermentation of glucose. Enzyme was produced using a variety of carbon substrates but the highest enzyme activity was detected in a medium containing 0.5% xylose and 1% glycerol (specific activity = 6.88 U/mg protein). Media containing only xylose or glucose gave lower enzyme productivies (specific activities= 4.60 and 2.35 U/mg protein respectively). The effects of nitrogen substrates on glucose isomerase production showed that yeast extract supported maximum enzyme activity (specific activity = 5.24 U/mg protein). Lowest enzyme activity was observed with sodium trioxonitrate (specific activity = 2.44 U/mg protein). In general, organic nitrogen substrates supported higher enzyme productivity than inorganic nitrogen substrates. Best enzyme activity was observed in the presence of Mg2+ (specific activity = 6.85 U/mg protein) while Hg2+ was inhibitory (specific activity = 1.02 U/mg protein). The optimum pH for best enzyme activity was 6.0 while optimum temperature for enzyme production was 50ºC.

scholarly journals A Novel Promising Strain ofTrichoderma evansii(WF-3) for Extracellularα-Galactosidase Production by Utilizing Different Carbon Sources under Optimized Culture Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Aishwarya Chauhan ◽  
Nikhat Jamal Siddiqi ◽  
Bechan Sharma
Keyword(s):  
Enzyme Activity ◽  
Wheat Straw ◽  
Guar Gum ◽  
Carbon Sources ◽  
Culture Conditions ◽  
Enzyme Synthesis ◽  
Basic Medium ◽  
Growth Media ◽  
Bean Meal ◽  
Soya Bean Meal

A potential fungal strain ofTrichodermasp. (WF-3) was isolated and selected for the production ofα-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Basal media selected for the growth of fungal isolate containing different carbon sources like guar gum (GG), soya bean meal (SM), and wheat straw (WS) and combinations of these carbon substrates with basic sugars like galactose and sucrose were used to monitor their effects onα-galactosidase production. The results of this study indicated that galactose and sucrose enhanced the enzyme activity in guar gum (GG) and wheat straw (WS). Maximumα-galactosidase production (213.63 UmL−1) was obtained when the basic medium containing GG is supplemented with galactose (5 mg/mL). However, the presence of galactose and sucrose alone in the growth media shows no effect. Soya meal alone was able to supportT. evansiito produce maximum enzyme activity (170.36 UmL−1). The incubation time, temperature, and pH for the maximum enzyme synthesis were found to be 120 h (5 days), 28°C, and 4.5–5.5, respectively. All the carbon sources tested exhibited maximum enzyme production at 10 mg/mL concentration. Among the metal ions tested, Hg was found to be the strongest inhibitor of the enzyme. Among the chelators, EDTA acted as stronger inhibitor than succinic acid.

scholarly journals Evaluation of pancreatin stability through enzyme activity determination

2016 ◽  
Vol 66 (3) ◽  
pp. 423-431 ◽  
Author(s):  
Gleysson De Paula Terra ◽  
Marcus Vinícius De Farias ◽  
Marcello Garcia Trevisan ◽  
Jerusa Simone Garcia
Keyword(s):  
Enzyme Activity ◽  
Stress Testing ◽  
Enzyme Stability ◽  
Uv Light ◽  
Influencing Factor ◽  
Storage Conditions ◽  
Porcine Pancreas ◽  
Pancreatic Diseases ◽  
Biotechnological Product ◽  
The Stability

Abstract Pancreatin is a biotechnological product containing an enzyme complex, obtained from porcine pancreas, that is employed in treating pancreatic diseases. Experiments regarding the stability of the pharmaceutical formulation containing pancreatin were performed using standard binary mixtures with 6 excipients in a 1:1 ratio (m/m) and a commercial formulation. To accomplish these goals, samples were stored for 1, 3 and 6 months at 40 ± 1 °C and 75 ± 5 % relative humidity (RH) and 40 ± 1 °C and 0 % RH. Stress testing was also performed. All samples were analyzed to evaluate the α-amylase, lipase and protease activities through UV/Vis spectrophotometry. The results revealed that the excipient proprieties and the storage conditions affected enzyme stability. Humidity was a strong influencing factor in the reduction of α-amylase and protease activities. Stress testing indicated that pH 9.0 and UV light did not induce substantial alterations in enzyme activity.

-CHYMOTRYPSIN IMMOBILIZED ENZYME: PHYSICAL, ACTIVITY & STABILITY PROPERTIES

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Mohd Hakimi Nazir ◽  
Norzita Ngadi
Keyword(s):  
Physical Properties ◽  
Immobilized Enzyme ◽  
Enzyme Stability ◽  
Sample Solution ◽  
Bet Surface Area ◽  
Adsorption Activity ◽  
Hy Zeolite ◽  
Isotherm Adsorption ◽  
The Stability ◽  
Stability Results

In this study, α-chymotrypsin enzyme was used as a substrate while micropore Y-zeolite, which is HY, USY and NaY as a support. The purpose of this study was to compare the physical properties of zeolite and immobilization of enzyme with zeolite.  The characteristics such as BET surface area, isotherm adsorption, BJH adsorption, pore size, t-plot and pore volume have been studied. Furthermore, a comparison has been conducted between immobilized and mobile enzyme for their ability to adsorb hydrolysate at λ=410 nm.  The stability of the immobilized enzyme was also determined by varying the parameters of phosphate and tris-chloride buffer and loading of sample solution. Based on the result obtained, HY zeolite has the best physical properties compared to USY and NaY zeolite.  Besides that, immobilized enzyme gave higher hydrolysate adsorption activity than the free enzyme. Stability results showed that pH of phosphate and tris-chloride buffer and amount of sample solution play an important role in obtaining the stable immobilized enzyme.   

Unprecedented Role of The N73-F124 Pair in The Staphylococcus equorum MnSOD Activity

2020 ◽  
Vol 16 ◽  
Author(s):  
Debbie Soefie Retnoningrum ◽  
Hiromi Yoshida ◽  
Muthia Dzaky Razani ◽  
Vincencius Felix Meidianto ◽  
Andrian Hartanto ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Active Site ◽  
Manganese Superoxide Dismutase ◽  
Enzyme Stability ◽  
The Other ◽  
Site Directed Mutagenesis ◽  
X Ray Crystallography ◽  
Staphylococcus Equorum ◽  
The Stability

Background:: Bacterial manganese superoxide dismutase (MnSOD) occurs as a dimer, which is responsible for its activity and stability. Thereby, increasing the dimeric strength would increase the enzyme stability while maintaining its activity. Objective:: An N73F substitution was introduced to strengthen interactions between the monomers at the dimer interface. This substitution would introduce a π-stacking interaction between F73 of one monomer to F124 from the other monomer. Method:: Site-directed mutagenesis was carried out to substitute N73 with phenylalanine. The activity of the mutant was qualitative- and quantitatively checked while the stability was evaluated with a fluorescence-based thermal-shift assay. Finally, the structure of the mutant was elucidated by means of X-ray crystallography. Results:: The N73F mutant activity was only ~40% of the wildtype. The N73F mutant showed one TM at 60+1oC while the wildtype has two (at 52-55oC and 63-67oC). The crystal structure of the mutant showed the interactions between F73 from one monomer to F124 from the other monomer. The N73F structure presents an enigma because of no change in the enzyme structure including the active site. Furthermore, N73 and F124 position and interaction are conserved in human MnSOD but with a different location in the amino acid sequence. N73 has a role in the enzyme activity that is likely related to its interaction with F124, which resides in the active site region but has not been considered to participate in the reaction. Conclusion:: The N73F substitution has revealed the unprecedented role of the N73-F124 pair in the enzyme activity.

Epitaxial Growth in Dislocation-Free Strained Alloy Films

2002 ◽  
Vol 715 ◽  
Author(s):  
Zhi-Feng Huang ◽  
Rashmi C. Desai
Keyword(s):  
Deposition Rate ◽  
Elastic Moduli ◽  
Composition Dependence ◽  
Critical Thickness ◽  
Lattice Misfit ◽  
Misfit Strain ◽  
Joint Stability ◽  
Alloy Films ◽  
The Stability ◽  
Stability Results

AbstractThe morphological and compositional instabilities in the heteroepitaxial strained alloy films have attracted intense interest from both experimentalists and theorists. To understand the mechanisms and properties for the generation of instabilities, we have developed a nonequilibrium, continuum model for the dislocation-free and coherent film systems. The early evolution processes of surface pro.les for both growing and postdeposition (non-growing) thin alloy films are studied through a linear stability analysis. We consider the coupling between top surface of the film and the underlying bulk, as well as the combination and interplay of different elastic effects. These e.ects are caused by filmsubstrate lattice misfit, composition dependence of film lattice constant (compositional stress), and composition dependence of both Young's and shear elastic moduli. The interplay of these factors as well as the growth temperature and deposition rate leads to rich and complicated stability results. For both the growing.lm and non-growing alloy free surface, we determine the stability conditions and diagrams for the system. These show the joint stability or instability for film morphology and compositional pro.les, as well as the asymmetry between tensile and compressive layers. The kinetic critical thickness for the onset of instability during.lm growth is also calculated, and its scaling behavior with respect to misfit strain and deposition rate determined. Our results have implications for real alloy growth systems such as SiGe and InGaAs, which agree with qualitative trends seen in recent experimental observations.

scholarly journals Maculansins, Cryptic Phytotoxins from Blackleg Fungi

2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600
Author(s):  
M. Soledade C. Pedras ◽  
Paulos B. Chumala
Keyword(s):  
Leptosphaeria Maculans ◽  
Culture Conditions ◽  
Fungal Species ◽  
Metabolic Characteristics ◽  
The Common

The phytotoxins and other metabolites produced by isolates L2/M2 of the fungal species Leptosphaeria maculans under different culture conditions, together with those of two new, but related isolates are disclosed. The common metabolic characteristics suggest a phylogenetic similarity between these isolates with potential to become widespread in mustard growing areas.

scholarly journals Extracellular α-Galactosidase from Trichoderma sp. (WF-3): Optimization of Enzyme Production and Biochemical Characterization

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Aishwarya Singh Chauhan ◽  
Arunesh Kumar ◽  
Nikhat J. Siddiqi ◽  
B. Sharma
Keyword(s):  
Enzyme Activity ◽  
Enzyme Assay ◽  
Biochemical Characterization ◽  
Catalytic Efficiency ◽  
Culture Conditions ◽  
Significant Loss ◽  
Trichoderma Sp ◽  
Rate Of Reaction ◽  
Higher Temperature ◽  
Substrate Concentrations

Trichoderma spp. have been reported earlier for their excellent capacity of secreting extracellular α-galactosidase. This communication focuses on the optimization of culture conditions for optimal production of enzyme and its characterization. The evaluation of the effects of different enzyme assay parameters such as stability, pH, temperature, substrate concentrations, and incubation time on enzyme activity has been made. The most suitable buffer for enzyme assay was found to be citrate phosphate buffer (50 mM, pH 6.0) for optimal enzyme activity. This enzyme was fairly stable at higher temperature as it exhibited 72% activity at 60°C. The enzyme when incubated at room temperature up to two hours did not show any significant loss in activity. It followed Michaelis-Menten curve and showed direct relationship with varying substrate concentrations. Higher substrate concentration was not inhibitory to enzyme activity. The apparent Michaelis-Menten constant (Km), maximum rate of reaction (Vmax), Kcat, and catalytic efficiency values for this enzyme were calculated from the Lineweaver-Burk double reciprocal plot and were found to be 0.5 mM, 10 mM/s, 1.30 U mg−1, and 2.33 U mg−1 mM−1, respectively. This information would be helpful in understanding the biophysical and biochemical characteristics of extracellular α-galactosidase from other microbial sources.

Effect of temperature and pH on the production, activity, and stability of α-amylase from Bacillus subtilis V37

2021 ◽  
Vol 66 (1) ◽  
pp. 72-79
Author(s):  
Thuoc Doan Van ◽  
Hung Nguyen Phuc
Keyword(s):  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Animal Feed ◽  
Culture Conditions ◽  
Effect Of Temperature ◽  
Physical Parameters ◽  
Original Activity ◽  
Optimum Ph ◽  
Production Activity ◽  
Ph Range

The effect of physical parameters such as temperature and pH on the production, activity, and stability of α-amylase from Bacillus subtilis V37 was investigated. The results indicated that the optimum culture conditions for enzyme activity were pH 7.0 and 35 oC. The optimum pH and temperature for enzyme activity were 6.0 and 70 oC. The crude enzyme was found to be stable in the pH range of 5.0 to 7.0. The enzyme was stable for 1 h at a temperature from 30 to 80 oC; nearly 100% of enzyme activity remained at temperatures of 30 - 40 oC, and about 34% of original activity remained at a temperature of 80 oC. These features demonstrated that α-amylase from B. subtilis V37 can be applied in many areas such as the food, fermentation, and animal feed industries.

scholarly journals Analysis of dengue model with fractal-fractional Caputo–Fabrizio operator

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Fatmawati ◽  
Muhammad Altaf Khan ◽  
Cicik Alfiniyah ◽  
Ebraheem Alzahrani
Keyword(s):  
Statistical Data ◽  
Dengue Infection ◽  
Fractional Operator ◽  
Novel Approach ◽  
Reduction Number ◽  
Best Fitting ◽  
The Stability ◽  
Parameter Values ◽  
Graphical Illustration ◽  
Stability Results

AbstractIn this work, we study the dengue dynamics with fractal-factional Caputo–Fabrizio operator. We employ real statistical data of dengue infection cases of East Java, Indonesia, from 2018 and parameterize the dengue model. The estimated basic reduction number for this dataset is $\mathcal{R}_{0}\approx2.2020$ R 0 ≈ 2.2020 . We briefly show the stability results of the model for the case when the basic reproduction number is $\mathcal{R}_{0} <1$ R 0 < 1 . We apply the fractal-fractional operator in the framework of Caputo–Fabrizio to the model and present its numerical solution by using a novel approach. The parameter values estimated for the model are used to compare with fractal-fractional operator, and we suggest that the fractal-fractional operator provides the best fitting for real cases of dengue infection when varying the values of both operators’ orders. We suggest some more graphical illustration for the model variables with various orders of fractal and fractional.

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