Improvement of delta-endotoxin production from local Bacillus thuringiensis Se13 using Taguchi’s orthogonal array methodology

2018 ◽  
Vol 43 (6) ◽  
pp. 662-670 ◽  
Author(s):  
Ardahan Eski ◽  
Zihni Demirbağ ◽  
İsmail Demir
Keyword(s):  
Bacillus Thuringiensis ◽  
Incubation Period ◽  
Orthogonal Array ◽  
Incubation Temperature ◽  
Taguchi Methods ◽  
Optimum Level ◽  
Optimum Conditions ◽  
Delta Endotoxin ◽  
Initial Ph ◽  
Four Levels

Abstract Objective The insecticidal activity of Bacillus thuringiensis directly depends on the yield of delta-endotoxins. In this study, various nutritional and cultural parameters influencing delta-endotoxin synthesis by a local isolate of B. thuringiensis Se13 were investigated using Taguchi methods. Methods In the first experiment, four factors, incubation period, incubation temperature, initial pH and medium, each at four levels, were selected and an orthogonal array layout of L16 was carried out. In the second experiment, Taguchi’s orthogonal array method of L27 was used to evaluate the effects of the different concentration of medium components. Taguchi’s signal–noise ratio and variance analysis were applied to determine the effect of the factors. After each experiment, verification studies were carried out using determined optimum conditions. Results The optimum conditions for incubation period, incubation temperature, initial pH, and medium determined as 72 h, 30°C, pH 9, and M4 medium, respectively. In the second experiment, soybean flour (5%), glucose (5%), KH2PO4 (0.3%), K2HPO4 (0.1%), MgSO4 (0.4%) were determined as the optimum conditions. The delta-endotoxin yield was elevated to 1559.25 μg mL−1 when the factors were adjusted to optimum level. Conclusion Optimization using the Taguchi method appeared to be a good choice for the overproduction of delta-endotoxin.

scholarly journals Optimum Conditions for Phenol Oxidase (Laccase) Production from Azotobacter chroococcum by Submerged Fermentation

2017 ◽  
Vol 11 (1) ◽  
pp. 13-18
Author(s):  
Ali J. R. AL-Sa'ady ◽  
Lamees M.R. Abbas ◽  
Hutaf A.A. ALsalim
Keyword(s):  
Incubation Period ◽  
Incubation Temperature ◽  
Nitrogen Sources ◽  
Phenol Oxidase ◽  
Azotobacter Chroococcum ◽  
Laccase Production ◽  
Optimum Conditions ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Production Conditions

Phenol oxidases (laccase), copper-containing oxidase enzymes, are found in many plants, fungi and microorganisms. Many factors that influence laccase production from Azotobacter chroococcum are determined in this study, these factors are: carbon source, nitrogen source, pH, incubation temperature and incubation period. The results showed that the best carbon and nitrogen sources for laccase production are sucrose and yeast extract respectively, and the best factors for laccase production conditions are pH 7.0 with an incubation period of 6 days at temperature 30 Cᵒ.

scholarly journals Study of the Optimal Conditions of Levan Production from a Local Isolate of Bacillus subtilis subsp. subtilis w36

2019 ◽  
Vol 32 (2) ◽  
pp. 213-222
Author(s):  
Wafaa H. Khassaf ◽  
Alaa K. Niamah ◽  
Alaa J. A. Al-Manhel
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Incubation Period ◽  
Growth Media ◽  
Optimal Conditions ◽  
Production Medium ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Inoculum Volume ◽  
Subtilis Subsp

The present study was aimed to test optimum conditions for the levan production from local isolation Bacillus subtilis subsp. subtilis w36, which was isolated from Basrah city soil by using production medium containing (40 g of sucrose as carbon source 10g pepton, 1g (NH4) 2SO4, 1g KH2PO4, 1g MgSO4.7H2O). The amount of levan produced was 4.9 g.ml-1. Molasses and date juice were used as substitutes for sucrose in growth media and substitute percentages were (25%, 50%, 75% and100%). The results showed the highest production of levan was recorded when sucrose was substituted with 25% molasses, which was 5.2 g.ml-1.Therefore, this medium was used to study optimum conditions included incubation period, inoculation volume, temperature ,initial pH. The highest production of levan was 6.8 g .100 ml-1 within 40 hours' incubation, 1 ml inoculum volume, pH 6.5 and 32 ºC.

Degradation of chlorpyriphos in water by advanced oxidation processes

2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro
Keyword(s):  
Reaction Time ◽  
Light Source ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
The Other ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Other Hand ◽  
Initial Ph

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.

scholarly journals Analysis of the molecular basis of insecticidal specificity of Bacillus thuringiensis crystal δ-endotoxin

1987 ◽  
Vol 248 (1) ◽  
pp. 197-201 ◽  
Author(s):  
M Z Haider ◽  
D J Ellar
Keyword(s):  
Bacillus Thuringiensis ◽  
Membrane Proteins ◽  
Insect Cell ◽  
Receptor Interaction ◽  
Dual Specificity ◽  
Delta Endotoxin ◽  
Cell Membrane Proteins ◽  
Toxin Receptor ◽  
Osmotic Lysis ◽  
Initial Interaction

The mechanism of action and receptor binding of a dual-specificity Bacillus thuringiensis var. aizawai ICl delta-endotoxin was studied using insect cell culture. The native protoxin was labelled with 125I, proteolytically activated and the affinity of the resulting preparations for insect cell-membrane proteins was studied by blotting. The active preparations obtained by various treatments had characteristic specificity associated with unique polypeptides, and showed affinity for different membrane proteins. The lepidopteran-specific preparation (trypsin-treated protoxin containing 58 and 55 kDa polypeptides) bound to two membrane proteins in the lepidopteran cells but none in the dipteran cells. The dipteran-specific preparation (protoxin treated sequentially with trypsin and Aedes aegypti gut proteases, containing a 53 kDa polypeptide) bound to a 90 kDa membrane protein in the dipteran (A. aegypti) cells but bound to none in the lepidopteran cells or Drosophila melanogaster cells. The toxicity of trypsin-activated delta-endotoxin was completely inhibited by preincubation with D-glucose, suggesting a role for this carbohydrate in toxin-receptor interaction. The toxicity was also decreased by osmotic protectants to an extent proportional to their viscometric radius. These results support a proposal that initial interaction of toxin with a unique receptor determines the specificity of the toxin, following which cell death occurs by a mechanism of colloid osmotic lysis.

Screening and Desilication of a Silicate Bacteria

2011 ◽  
Vol 236-238 ◽  
pp. 253-257
Author(s):  
Xian Zhen Zhang ◽  
De Si Sun ◽  
Hai Lin
Keyword(s):  
Particle Size ◽  
Incubation Time ◽  
Ph Value ◽  
Solution Temperature ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Silicate Bacteria ◽  
Bauxite Ore

The strain Jgj-1 was isolated from Gaoan bauxite ore. The relations of desilication of the strain Jgj-1 and the pH of solution, temperature, shaking speed, incubation time, particle size were investigated. The results shows the optimum conditions of bioleaching are as following: at 28°C, initial pH value is 7.2, particle size 0.056mm, 200rpm shaking speed, incubation 5-7 days.

Decolorization of Reactive Black 5 using Peroxymonosulfate in Fentonlike Process

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Gülin Ersöz ◽  
Süheyda Atalay
Keyword(s):  
Advanced Oxidation Processes ◽  
Catalytic Effect ◽  
Industrial Effluents ◽  
Operating Parameters ◽  
Reactive Black 5 ◽  
Process Performance ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Wide Availability ◽  
Initial Ph

AbstractOne of the advanced oxidation processes, the Oxone process, was studied to determine its effects on the decolorization of Reactive Black 5 (RB5) in an aqueous solution. Ferrous ion was chosen as the transition metal due to its potential catalytic effect and wide availability in dye containing industrial effluents. The effects of the operating parameters such as Fe(II) and Oxone concentration, initial pH, and temperature on the process performance were investigated. The optimum conditions were determined as: 0.5 mM of Oxone concentration, 0.5 mM of Fe

scholarly journals Enzyme optimization to reduce the viscosity of pitanga (Eugenia uniflora L.) juice

2016 ◽  
Vol 19 (0) ◽  
Author(s):  
Ricardo Schmitz Ongaratto ◽  
Luiz Antonio Viotto
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Incubation Time ◽  
Regression Models ◽  
Incubation Temperature ◽  
Correlation Coefficients ◽  
Enzyme Concentration ◽  
Optimum Conditions ◽  
Activity Time ◽  
Independent Variables

Summary The aim of this work was to separately evaluate the effects of pectinase and cellulase on the viscosity of pitanga juice, and determine the optimum conditions for their use employing response surface methodology. The independent variables were pectinase concentration (0-2.0 mg.g–1) and cellulase concentration (0-1.0 mg.g–1), activity time (10-110 min) and incubation temperature (23.2-56.8 °C). The use of pectinase and cellulase reduced the viscosity by about 15% and 25%, respectively. The results showed that enzyme concentration was the most important factor followed by activity time, and for the application of cellulase the incubation temperature had a significant effect too. The regression models showed correlation coefficients (R2) near to 0.90. The pectinase application conditions that led to the lowest viscosity were: concentration of 1.7 mg.g–1, incubation temperature of 37.6 °C and incubation time of 80 minutes, while for cellulase the values were: concentration of 1.0 mg.g-1, temperature range of 25 °C to 35 °C and incubation time of 110 minutes.

scholarly journals Biogas Production from Combined Irish Potato and Poultry Wastes: Optimization and Kinetic Studies

2018 ◽  
Vol 7 (3.36) ◽  
pp. 170
Author(s):  
Umar M. Ibrahim ◽  
Saeed I. Ahmed ◽  
Babagana Gutti ◽  
Idris M. Muhammad ◽  
Usman D. Hamza ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Parameters ◽  
Ph Value ◽  
Biogas Production ◽  
Irish Potato ◽  
Coefficient Of Determination ◽  
Optimum Conditions ◽  
Biogas Yield ◽  
Potato Waste ◽  
Initial Ph

The combination of Irish potato waste (IPW) and poultry waste (PW) can form a synergy resulting into an effective substrate for a better biogas production due to some materials they contain. In this work, optimization and kinetic study of biogas production from anaerobic digestion of IPW and PW was investigated. Response surface methodology (RSM) was applied to optimize conditions such as initial pH, solids concentrations and waste ratios. The anaerobic digestion of the two wastes was carried out in the mesophilic condition and Box-Behnken design (BBD) was used to develop and analyze a predictive model which describes the biogas yield. The results revealed that there is a good fit between the experimental and the predicted biogas yield as revealed by the coefficient of determination (R2) value of 97.93%. Optimization using quadratic RSM predicts biogas yield of 19.75% at the optimal conditions of initial pH value 7.28, solids concentration (w/v) 9.85% and waste ratio (IPW:PW) 45:55%. The reaction was observed to have followed a first order kinetics having R2 and relative squared error (RSE) values of 90.61 and 9.63% respectively. Kinetic parameters, such as rate constant and half-life of the biogas yield were evaluated at optimum conditions to be 0.0392 day-1 and 17.68 days respectively. The optimum conditions and kinetic parameters generated from this research can be used to design real bio-digesters, monitor substrate concentrations, simulate biochemical processes and predict performance of bio-digesters using IPW and PW as substrate.  

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