scholarly journals Optimization of L-asparaginase production from Escherichia coli using response surface methodology

2020 ◽  
Vol 16 (4) ◽  
pp. 767-775
Author(s):  
Nguyen Thi Hien Trang ◽  
Le Thanh Hoang ◽  
Do Thi Tuyen
Keyword(s):  
Escherichia Coli ◽  
Response Surface Methodology ◽  
Recombinant Protein ◽  
Response Surface ◽  
Lymphoblastic Leukemia ◽  
Quadratic Model ◽  
Shake Flask Culture ◽  
Cultivation Conditions ◽  
Maldi Tof ◽  
Optimized Conditions

Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. In previous study, the L-asparaginase from Erwinia chrysanthermy was expressed in Escherichia coli BL21(DE3). The recombinant L-asparaginase was produced from recombinant E.coli BL21(DE3) under different cultivation conditions (inducer concentration, inoculum concentration and KH2PO4 concentration). The optimized conditions by response surface methodology using face centered central composite design. The analysis of variance coupled with larger value of R2 (0.9) showed that the quadratic model used for the prediction was highly significant (p < 0.05). Under the optimized conditions, the model produced L-asparaginase activity of 123.74 U/ml at 1.03 mM IPTG, 3% (v/v) inoculum and 0.5% (w/v) KH2PO4. Recombinant protein was purified by two step using gel filtration and DEAE chromatography. The purified L-asparaginase had a molecular mass of 37 kDa with specific activity of 462 U/mg and identified by MALDI-TOF mass spectrometry. Results of MALDI-TOF analysis confirmed that recombinant protein was L-asparaginase II. Recombinant L-asparaginase has antiproliferative activity with K562 cell line. In conclusion, this study has innovatively developed cultivation conditions for better production of recombinant L-asparaginase in shake flask culture.

Optimization of photo-Fenton process of RO concentrated coking wastewater using response surface methodology

2012 ◽  
Vol 66 (4) ◽  
pp. 816-823 ◽  
Author(s):  
Zhang Huiqing ◽  
Ye Chunsong ◽  
Zhang Xian ◽  
Yang Fan ◽  
Yang Jun ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Ph Value ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Coking Wastewater ◽  
Fenton Process ◽  
Predicted Values ◽  
Optimized Conditions

The objective of this study was aimed at investigating the removal of chemical oxygen demand (COD) from reverse osmosis (RO) concentrated coking wastewater by the photo-Fenton process. The optimum extraction conditions for the photo-Fenton process by Box–Behnken design (BBD) and response surface methodology (RSM) to establish a predictive polynomial quadratic model were discussed based on a single factor test. Optimized parameters validated by the analysis of variances (ANOVA) were found to be H2O2 concentration of 345.2 mg/L, pH value of 4.1 and reaction time of 103.5 minutes under ultraviolet irradiation. The experimental results of the COD removal under the optimized conditions presented better agreement with the predicted values with deviation error of 3.2%. The results confirmed that RSM based on BBD was a suitable method to optimize the operating conditions of RO concentrated coking wastewater.

EXTRACTION OPTIMIZATION AND ANTIOXIDANT ACTIVITY OF PHENOLIC COMPOUNDS FROM AVOCADO PEEL

2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Antioxidant Capacity ◽  
Response Surface ◽  
Total Antioxidant Capacity ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Quadratic Model ◽  
Total Phenolic ◽  
Total Antioxidant

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel

Enzyme-assisted Extraction for Optimized Recovery of Phenolic Bioactives from Peganum hermala Leaves Using Response Surface Methodology

2018 ◽  
Vol 17 (4) ◽  
pp. 349-354
Author(s):  
Qadir Rahman ◽  
Anwar Farooq ◽  
Amjad Gilani Mazhar ◽  
Nadeem Yaqoob Muhammad ◽  
Ahmad Mukhtar
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Enzyme Concentration ◽  
Coumaric Acid ◽  
Assisted Extraction ◽  
Pre Treatment ◽  
Optimized Conditions ◽  
Enzyme Complexes ◽  
Hydrolysis Of ◽  
Central Composite

This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuzyme) on recovery of phenolics from Peganum hermala (harmal) leaves, under optimized conditions using response surface methodology. As compared to the other enzyme complexes, the yield (34 g/100g) obtained through Zympex-014-assisted extraction was higher under optimized conditions such as time (75 min), temperature (70°C), pH (6.5) and enzyme concentration (5 g/100 g) using central composite design (CCD). Effectiveness of Zympex-014 towards hydrolysis of P. hermala leaves cell wall was examined by analyzing the control and enzyme-treated leave residues using scanning electron microscope (SEM). GC/MS characterization authenticated the presence of quercetin (1.44), gallic acid (0.23), caffeic acid (0.04), cinnamic acid (0.05), m-coumaric acid (0.23) and p-coumaric acid (0.37 μg/g) as the potent phenolics in Zympex-014 based extract. It can be concluded from the findings of the current work that pre-treatment of P. hermala leaves with Zympex-014 significantly enhanced the recovery of phenolics that supports its potential uses in the nutra-pharamaceutical industry.

scholarly journals Optimization of Lignin Extraction Variables by Response Surface Methodology from Pine Saw Dust, and Quantification of Major Structural Units in Isolated Lignin Fraction

2021 ◽  
Vol 11 (4) ◽  
pp. 1739
Author(s):  
Muhammad Ajaz Ahmed ◽  
Jae Hoon Lee ◽  
Joon Weon Choi
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Quantum Coherence ◽  
Resonance Spectrum ◽  
Quadratic Model ◽  
Molecular Weights ◽  
Solids Loading ◽  
A Value ◽  
Lignin Extraction ◽  
Lignin Fraction

A synergistic combination of dioxane, acetic acid, and HCl was investigated for lignin extraction from pine wood biomass. After initial screening of reagent combination, response surface methodology (RSM) was used to optimize the lignin yield with respect to the variables of time 24–72 h, solids loading 5–15%, and catalyst dose 5–15 mL. A quadratic model predicted 8.33% of the lignin yield, and it was further confirmed experimentally and through the analysis of variance (ANOVA). Lignin at optimum combination exhibited features in terms of derivatization followed by reductive cleavage (DFRC) with a value of (305 µmol/gm), average molecular weights of 4358 and polydispersity of 1.65, and 2D heteronuclear single quantum coherence nuclear magnetic resonance spectrum (2D-HSQC NMR) analysis showing relative β-O-4 linkages (37.80%). From here it can be suggested that this fractionation can be one option for high quality lignin extraction from lignocellulosic biomass.

scholarly journals Optimizing Adsorption of 17α-Ethinylestradiol from Water by Magnetic MXene Using Response Surface Methodology and Adsorption Kinetics, Isotherm, and Thermodynamics Studies

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3150
Author(s):  
Mengwei Xu ◽  
Chao Huang ◽  
Jing Lu ◽  
Zihan Wu ◽  
Xianxin Zhu ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Quadratic Model ◽  
Adsorption Efficiency ◽  
Process Variables ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Independent Variables ◽  
The Impact ◽  
Adsorbent Dose

Magnetic MXene composite Fe3O4@Ti3C2 was successfully prepared and employed as 17α-ethinylestradiol (EE2) adsorbent from water solution. The response surface methodology was employed to investigate the interactive effects of adsorption parameters (adsorption time, pH of the solution, initial concentration, and the adsorbent dose) and optimize these parameters for obtaining maximum adsorption efficiency of EE2. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. Optimization of the process variables for maximum adsorption of EE2 by Fe3O4@Ti3C2 was performed using the quadratic model. The model predicted maximum adsorption of 97.08% under the optimum conditions of the independent variables (adsorption time 6.7 h, pH of the solution 6.4, initial EE2 concentration 0.98 mg L−1, and the adsorbent dose 88.9 mg L−1) was very close to the experimental value (95.34%). pH showed the highest level of significance with the percent contribution (63.86%) as compared to other factors. The interactive influences of pH and initial concentration on EE2 adsorption efficiency were significant (p < 0.05). The goodness of fit of the model was checked by the coefficient of determination (R2) between the experimental and predicted values of the response variable. The response surface methodology successfully reflects the impact of various factors and optimized the process variables for EE2 adsorption. The kinetic adsorption data for EE2 fitted well with a pseudo-second-order model, while the equilibrium data followed Langmuir isotherms. Thermodynamic analysis indicated that the adsorption was a spontaneous and endothermic process. Therefore, Fe3O4@Ti3C2 composite present the outstanding capacity to be employed in the remediation of EE2 contaminated wastewaters.

Optimization on Influencing Factors of Fracture Toughness of Corundum-Mullite Toughened by In Situ Synthesized Mullite Whiskers by Response Surface Methodology

2012 ◽  
Vol 581-582 ◽  
pp. 819-822 ◽  
Author(s):  
Bin Meng ◽  
Jin Hui Peng
Keyword(s):  
Fracture Toughness ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Response Surface Method ◽  
Sintering Temperature ◽  
Surface Method ◽  
Mullite Whiskers ◽  
Optimized Conditions ◽  
Addition Amount

The corundum-mullite was toughened by in-situ synthesized mullite whiskers and the process parameters influencing the fracture toughness of corundum-mullite, such as sintering temperature, addition amount of AlF3 and V2O5, were optimized by means of response surface method. Corundum-mullite with fracture toughness of 9.44 MPa.m-1/2 could be obtained under the optimized conditions, i.e. sintering temperature of 1400°C, 4.8 wt.% of AlF3 and 5.8 wt.% of V2O5. The results showed that it was feasible to prepare corundum-mullite toughened by in-situ synthesized mullite whiskers by the optimized parameters. In addition, an accurate model based on response surface method was proposed to predict the experimental results.

scholarly journals Rheological properties of emulsions stabilized by green banana (Musa cavendishii) pulp fitted by power law model

2009 ◽  
Vol 52 (6) ◽  
pp. 1541-1553 ◽  
Author(s):  
Dayane Rosalyn Izidoro ◽  
Agnes de Paula Scheer ◽  
Maria-Rita Sierakowsk
Keyword(s):  
Response Surface Methodology ◽  
Rheological Properties ◽  
Response Surface ◽  
Power Law ◽  
Cone Angle ◽  
Rheological Behaviour ◽  
Quadratic Model ◽  
Soy Oil ◽  
Power Law Model ◽  
Green Banana

In this work, the rheological behaviour of emulsions (mayonnaises) stabilized by green banana pulp using the response surface methodology was studied. In addition, the emulsions stability was investigated. Five formulations were developed, according to design for constrained surfaces and mixtures, with the proportion, respectively: water/soy oil/green banana pulp: F1 (0.10/0.20/0.70), F2 (0.20/0.20/0.60), F3 (0.10/0.25/0.65), F4 (0.20/0.25/0.55) and F5 (0.15/0.225/0.625) .Emulsions rheological properties were performed with a rotational Haake Rheostress 600 rheometer and a cone and plate geometry sensor (60-mm diameter, 2º cone angle), using a gap distance of 1mm. The emulsions showed pseudoplastic behaviour and were adequately described by the Power Law model. The rheological responses were influenced by the difference in green banana pulp proportions and also by the temperatures (10 and 25ºC). The formulations with high pulp content (F1 and F3) presented higher shear stress and apparent viscosity. Response surface methodology, described by the quadratic model,showed that the consistency coefficient (K) increased with the interaction between green banana pulp and soy oil concentration and the water fraction contributed to the flow behaviour index increase for all emulsions samples. Analysis of variance showed that the second-order model had not significant lack-of-fit and a significant F-value, indicating that quadratic model fitted well into the experimental data. The emulsions that presented better stability were the formulations F4 (0.20/0.25/0.55) and F5 (0.15/0.225/0.625).

scholarly journals Optimizing Physiochemical and Sensory Properties of Infrared-Hot Air Roasted Sunflower Kernels Using Response Surface Methodology

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Mahdis Mosayebi ◽  
Mahdi Kashaninejad ◽  
Leila Najafian
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Color Change ◽  
Specific Energy Consumption ◽  
Chemical Properties ◽  
Sensory Properties ◽  
Quadratic Model ◽  
Total Phenolic ◽  
Phenolic Contents ◽  
Hot Air

Roasting sunflower kernels is a key process in production of nuts. In this study, the effect of roasting conditions, including hot air temperature (120–160°C), infrared (IR) power (400–600 W) and roasting time (3–10 min) on energy and specific energy consumption, color parameters (L∗, a∗, b∗, ΔE, BI, SI, WI, and h°), texture, moisture content, chemical properties (pH and total phenolic contents, peroxide value (PV), and sensory properties of sunflower kernel were investigated. In addition, the best models for the responses were obtained, and the proper roasting conditions were determined using response surface methodology (RSM). A quadratic model was proposed for color change (L∗, ΔE, SI, and WI), moisture and total phenol contents, linear relation for a∗, b∗, h°, and 2FI for BI, texture, PV, and pH. Roasting at 425.7 W IR power and 124.3°C for 3.7 min was found to be convenient or proper roasting conditions.

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