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

2018 ◽  
Vol 17 (1) ◽  
pp. 39-49 ◽  
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.

scholarly journals Application of Response Surface Methodology for Optimization of Siderophore Production

2021 ◽  
Author(s):  
R.U. Raje Nimbalkar ◽  
N.S. Barge ◽  
R.J. Marathe ◽  
Y.B. Phatake ◽  
R.B. Deshmukh ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
16S Rrna Gene Sequencing ◽  
Culture Conditions ◽  
Siderophore Production ◽  
Rrna Gene ◽  
Rhizospheric Soil ◽  
Factors Affecting ◽  
Cas Assay ◽  
Rrna Gene Sequencing

Background: In the present study a statistical model (Response Surface Methodology) was proposed for optimization of siderophore production by using Enterobacter hormaechei.Methods: The rhizospheric soil was used for isolation and isolates were screened for siderophore production by chrome-azurol S (CAS) assay. One potent isolate producing maximum siderophore was selected and characterized by 16S rRNA gene sequencing. The culture conditions were optimized for maximum siderophore production by using Central Composite Design. The response surface curves were used to predict the optimum levels of the factors affecting the yield of siderophore. Result: By using rhizospheric soil,eight isolates were obtained and one potent organism was identified as Enterobacter hormaechei subsp. oharae (Accession No. MT 775835) by BLAST. The maximum siderophore production (98%) was obtained in succinate medium and the optimum values of variables were found as pH 7, time 60 hrs, temp. 28°C and succinic acid conc. 0.40%. RSM was used to analyze the data by developing 3D surface plots and the residuals plots. ANOVA was used to determine regression coefficients.

scholarly journals Isolation, Identification and Characterization of Bioflocculant-Producing Bacteria from Activated Sludge of Vulindlela Wastewater Treatment Plant

2021 ◽  
Vol 1 (3) ◽  
pp. 586-606
Author(s):  
Nkanyiso Celukuthula Nkosi ◽  
Albertus K. Basson ◽  
Zuzingcebo G. Ntombela ◽  
Tsolanku S. Maliehe ◽  
Rajasekhar V. S. R. Pullabhotla
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
16S Rrna Gene Sequencing ◽  
Industrial Applications ◽  
Culture Conditions ◽  
Inoculum Size ◽  
Medium Composition ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Optimal Medium

The low microbial flocculant yields and efficiencies limit their industrial applications. There is a need to identify bacteria with high bioflocculant production. The aim of this study was to isolate and identify a bioflocculant-producing bacterium from activated sludge wastewater and characterise its bioflocculant activity. The identification of the isolated bacterium was performed by 16S rRNA gene sequencing analysis. The optimal medium composition (carbon and nitrogen sources, cations and inoculum size) and culture conditions (temperature, pH, shaking speed and time) were evaluated by the one-factor-at-a-time method. The morphology, functional groups, crystallinity and pyrolysis profile of the bioflocculant were analysed using scanning electron microscope (SEM), Fourier transform infrared (FTIR) and thermogravimetric (TGA) analysis. The bacterium was identified as Proteus mirabilis AB 932526.1. Its optimal medium and culture conditions were: sucrose (20 g/L), yeast extract (1.2 g/L), MnCl2 (1 g/L), pH 6, 30 °C, inoculation volume (3%), shaking speed (120 rpm) for 72 h of cultivation. SEM micrograph revealed the bioflocculant to be amorphous. FTIR analysis indicated the presence of hydroxyl, carboxyl and amino groups. The bioflocculant was completely pyrolyzed at temperatures above 800 °C. The bacterium has potential to produce bioflocculant of industrial importance.

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

2017 ◽  
Vol 69 (3) ◽  
pp. 469-480 ◽  
Author(s):  
Jamil Shafi ◽  
Ji Mingshan ◽  
Qi Zhiqiu ◽  
Li Xiuwei ◽  
Gu Zumin ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Antifungal Activity ◽  
Response Surface ◽  
Botrytis Cinerea ◽  
Incubation Period ◽  
Incubation Temperature ◽  
Interactive Effect ◽  
Dry Mass ◽  
Rrna Gene ◽  
Fermentation Conditions

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.

scholarly journals First case of an invasive Bacteroides dorei infection detected in a patient with a mycotic aortic aneurysm—raising a rebellion of major indigenous bacteria in humans: a case report and review

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Takayuki Matsuoka ◽  
Takuya Shimizu ◽  
Tadanori Minagawa ◽  
Wakiko Hiranuma ◽  
Miki Takeda ◽  
...  
Keyword(s):  
Aortic Aneurysm ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Resected Specimen ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
First Case ◽  
Rrna Gene Sequencing

Abstract Background Bacteroides dorei is an anaerobic gram-negative bacterium first described in 2006. Because of the high similarity in mass spectra between B. dorei and Bacteroides vulgatus, discriminating between these species is arduous in clinical practice. In recent decades, 16S rRNA gene sequencing has been a complementary method for distinguishing taxonomically close bacteria, including B. dorei and B. vulgatus, at the genus and species levels. Consequently, B. dorei has been shown to contribute to some diseases, including type 1 autoimmune diabetes mellitus and atherosclerotic diseases. However, there are no reports on invasive infectious diseases caused by B. dorei. This report describes the first case of direct invasion and colonisation of human tissue by B. dorei, thus providing a warning regarding the previously proposed application of B. dorei as a live biotherapeutic for atherosclerotic diseases. Case presentation A 78-year-old Japanese man complained of intermittent chest/back pain and was diagnosed with a mycotic thoracic aortic aneurysm by enhanced computed tomography on admission. Despite strict blood pressure control and empirical antibiotic therapy, the patient’s condition worsened. To prevent aneurysmal rupture and eliminate infectious foci, the patient underwent surgical treatment. The resected specimen was subjected to tissue culture and 16S rRNA gene sequencing analysis to identify pathogenic bacteria. A few days after the surgery, culture and sequencing results revealed that the pathogen was B. dorei/B. vulgatus and B. dorei, respectively. The patient was successfully treated with appropriate antibacterial therapy and after improvement, was transferred to another hospital for rehabilitation on postoperative day 34. There was no recurrence of infection or aneurysm after the patient transfer. Conclusions This report describes the first case of invasive infectious disease caused by B. dorei, casting a shadow over its utilisation as a probiotic for atherosclerotic diseases.

scholarly journals Determination of important enzymes and antimicrobial resistances of gram-positive haloalkaliphilic bacteria isolated from Salda Lake

2021 ◽  
Vol 38 (3) ◽  
pp. 375-382
Author(s):  
Pınar Çağlayan
Keyword(s):  
Bacillus Subtilis ◽  
Soda Lakes ◽  
Soda Lake ◽  
16S Rrna Gene Sequencing ◽  
Extreme Environment ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Haloalkaliphilic Bacteria ◽  
Rrna Gene Sequencing

As an extreme environment, soda lakes harbor various haloalkaliphilic microorganisms. Salda Lake is one of the natural soda lake (pH˃9) in Turkey. Haloalkaliphiles are unique microorganisms in their ability to live in high alkaline and high saline conditions, and play an important role in biodegradation and bioremediation of hydrocarbons. Hence, the aims of this study were to isolate haloalkaliphilic bacteria from water sample of Salda Lake, to identify these isolates by both conventional and molecular methods, to screen their industrially important enzymes, and to investigate their antimicrobial resistance profiles. Six isolates were identified as Bacillus horneckiae, Bacillus subtilis, Bacillus paramycoides, Bacillus pumilus, Staphylococcus epidermidis, Bacillus haynesii according to 16S rRNA gene sequencing analysis. The industrially important enzymes (amylase, cellulase, pullulanase, lipase, urease, protease, caseinase, oxidase, catalase) were produced by haloalkaliphilic isolates. These enzymes maybe used in alkaline and saline industrial processes. Although Bacillus subtilis was susceptible to all antibiotics, other isolates showed resistance to at least one antibiotic. The resistance against antibiotics were found as ampicillin/sulbactam 83%, amoxycillin/clavulanic acid 83%, ampicillin 67%, mupirocin 67%, chloramphenicol 50%, tetracycline 50%, imipenem 50%, meropenem 50%, cefadroxil 17%. These bacteria may have develope resistance to antibiotics that entering their natural environment in different ways.

scholarly journals Application of electrochemical peroxidation (ECP) process for waste-activated sludge stabilization and system optimization using response surface methodology (RSM)

2018 ◽  
Vol 77 (6) ◽  
pp. 1765-1776 ◽  
Author(s):  
Gagik Badalians Gholikandi ◽  
Khashayar Kazemirad
Keyword(s):  
Response Surface Methodology ◽  
Activated Sludge ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
System Optimization ◽  
Waste Activated Sludge ◽  
Operational Conditions ◽  
Sludge Stabilization ◽  
Rsm Optimization

Abstract In this study, the performance of the electrochemical peroxidation (ECP) process for removing the volatile suspended solids (VSS) content of waste-activated sludge was evaluated. The Fe2+ ions required by the process were obtained directly from iron electrodes in the system. The performance of the ECP process was investigated in various operational conditions employing a laboratory-scale pilot setup and optimized by response surface methodology (RSM). According to the results, the ECP process showed its best performance when the pH value, current density, H2O2 concentration and the retention time were 3, 3.2 mA/cm2, 1,535 mg/L and 240 min, respectively. In these conditions, the introduced Fe2+ concentration was approximately 500 (mg/L) and the VSS removal efficiency about 74%. Moreover, the results of the microbial characteristics of the raw and the stabilized sludge demonstrated that the ECP process is able to remove close to 99.9% of the coliforms in the raw sludge during the stabilization process. The energy consumption evaluation showed that the required energy of the ECP reactor (about 1.8–2.5 kWh (kg VSS removed)−1) is considerably lower than for aerobic digestion, the conventional waste-activated sludge stabilization method (about 2–3 kWh (kg VSS removed)−1). The RSM optimization process showed that the best operational conditions of the ECP process comply with the experimental results, and the actual and the predicted results are in good conformity with each other. This feature makes it possible to predict the introduced Fe2+ concentrations into the system and the VSS removal efficiency of the process precisely.

Bioremediation Condition Optimization of Hydrocarbon in Soil Using Response Surface Methodology by Microbial Consortium KL9-1

2012 ◽  
Vol 518-523 ◽  
pp. 2073-2078 ◽  
Author(s):  
Qi You Liu ◽  
Yun Bo Zhang ◽  
Dong Feng Zhao ◽  
Chao Cheng Zhao
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Microbial Consortium ◽  
Ph Value ◽  
Removal Rate ◽  
Desirability Function ◽  
Nitrogen And Phosphorus ◽  
Predictive Values ◽  
Independent Variables ◽  
Condition Optimization

A response surface methodology was applied to optimize the bioremediation condition of hydrocarbon in soil by microbial consortium KL9-1. A four-level Box-Behnken factorial design was employed to study the relationship of independent variables and dependent variable by applying pH value, inoculation amount of microbial consortium KL9-1, ratio of nitrogen and phosphorus (N/P ) and surfactant (SDBS) concentration as independent variables (factors) and crude oil removal rate as dependent variable (response). Then the statistically significant model was obtained and numerical optimization based on desirability function was carried out for pH 7.0, inoculation amount 50.0 mL, N/P 2: 1 and SDBS concentration 4.0 g, and the hydrocarbon removal rate reached as high as 52.58%. The predictive values showed good agreement with the experimental values under the optimization conditions, by standard variance <1.3%. It showed that the optimal result was reliable.

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