Optimization of Bacillus aerius strain JS-786 cell dry mass and its antifungal activity against Botrytis cinerea using response surface methodology

The optimization of fermentation conditions is necessary for field application of biological control agents. The present study was designed to optimize the fermentation conditions for the Bacillus aerius strain, JS-786 in terms of cell dry mass and its antifungal activity against Botrytis cinerea with response surface methodology. A strain of bacteria with strong antifungal activity was isolated from the phyllosphere of tomato plant and identified as B. aerius JS-786 based on the sequence homology of its 16S rRNA gene. After the success of preliminary antifungal activity tests, response surface methodology was used to optimize the fermentation conditions (medium pH, gelatin percentage, incubation period, rotatory speed and incubation temperature) to maximize the cell dry mass and antifungal activity against B. cinerea. A 25 factorial central composite design was employed and multiple response optimization was used to determine the desirability of the operation. The results of regression analysis showed that at the individual level, all of the experimental parameters were significant for cell dry mass; significant results were obtained for antifungal activity pH, incubation period, rotatory speed and incubation temperature. The interactive effect of the incubation period, rotatory speed and incubation temperature was significant. Maximum cell dry mass (8.7 g/L) and inhibition zone (30.4 mm) were obtained at pH 6.4, gelatin 3.2%, incubation period 36.92 h, rotatory speed 163 rpm, and temperature 33.5?C. This study should help to formulate a more rational and cost-effective biological product both in terms of bacterial growth and antifungal activity.

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Modeling and Statistical Optimization of Culture Conditions for Improvement of Antifungal Compounds Production by Streptomyces albidoflavus S19 Strain of Wastewater Origin

Anti-Infective Agents ◽

10.2174/2211352516666180813102424 ◽

2018 ◽

Vol 17 (1) ◽

pp. 39-49 ◽

Cited By ~ 3

Author(s):

S. Souagui ◽

W. Djoudi ◽

H. Boudries ◽

M. Béchet ◽

V. Leclére ◽

...

Keyword(s):

Response Surface Methodology ◽

Antifungal Activity ◽

Response Surface ◽

Ph Value ◽

16S Rrna Gene Sequencing ◽

Culture Conditions ◽

Rrna Gene ◽

Sequencing Analysis ◽

Promising Alternative ◽

Antifungal Metabolites

Background: The actinomycetes strains isolated from unexplored ecosystems are a promising alternative for the biosynthesis of novel antimicrobial compounds. Depending on the interesting antifungal activity of the studied strain S19, the statistical method seems to be an effective tool for optimizing the production of anticandidal molecules. Introduction: This study was conducted in order to optimize the culture parameters (medium nutrients concentrations and initial pH value) affecting the production of antifungal metabolites from S. albidoflavus strain S19 (obtained from wastewater collected in Bejaia region, Algeria) using Response Surface Methodology (RSM). The best conditions for anti-Candida albicans compounds biosynthesis were determined. Methods and Results: The antimicrobial producer strain S. albidoflavus S19 was identified on the basis of morphological, chemicals characters and physiological characteristics along with 16S rRNA gene sequencing analysis. Response Surface Methodology by Central Composite Design (CCD) was employed to improve the anti- C. albicans agents production through the optimization of medium parameters. The highest antifungal activity was obtained by using a mixture of 2g l-1 starch, 4g l-1 yeast extract, 2g l-1 peptone at pH 11. Conclusion: The strain S19 isolated from wastewater showed a significant anti-C. albicans activity and this study revealed the effectiveness of RSM and CCD for increasing bioactive compounds production, rising the diameter of inhibition zones from 13 to 34 mm.

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Response surface methodology approach for the optimisation of adsorption of hydrolysed polyacrylamide from polymer-flooding wastewater onto steel slag: a good option of waste mitigation

Water Science & Technology ◽

10.2166/wst.2017.245 ◽

2017 ◽

Vol 76 (4) ◽

pp. 776-784 ◽

Cited By ~ 2

Author(s):

Mijia Zhu ◽

Jun Yao ◽

Zhonghai Qin ◽

Luning Lian ◽

Chi Zhang

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Removal Efficiency ◽

Contact Time ◽

Interactive Effect ◽

Steel Slag ◽

Oxygen Demand ◽

Polymer Flooding ◽

High Concentration ◽

Adsorbent Dosage

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.

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

BRAZILIAN JOURNAL OF FOOD TECHNOLOGY ◽

10.1590/1981-6723.4115 ◽

2016 ◽

Vol 19 (0) ◽

Cited By ~ 3

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.

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