scholarly journals Optimization of the medium composition for production of antimicrobial substances by bacillus subtilis ATCC 6633

2017 ◽  
pp. 245-259
Author(s):  
Zorana Roncevic ◽  
Jovana Djuran ◽  
Jovana Grahovac ◽  
Sinisa Dodic ◽  
Aleksandra Ranitovic ◽  
...  

In the effort to overcome the increase in antimicrobial resistance of different pathogens, natural products from microbial sources appear to be the most favorable alternative to current antibiotics. Production of antimicrobial compounds is highly dependent on the nutritional conditions. Hence, in order to achieve high product yields, selection of the media constituents and optimization of their concentrations are required. In this research, the possibility of antimicrobial substances production using Bacillus subtilis ATCC 6633 was investigated. Also, optimization of the cultivation medium composition in terms of contents of glycerol, sodium nitrite and phosphates was done. Response surface methodology and the method of desirability function were applied for determination of optimal values of the examined factors. The developed model predicts that the maximum inhibition zone diameters for Bacillus cereus ATCC 10876 (33.50 mm) and Pseudomonas aeruginosa ATCC 27853 (12.00 mm) are achieved when the initial contents of glycerol, sodium nitrite and phosphates were 43.72 g/L, 1.93 g/L and 5.64 g/L, respectively. The results of these experiments suggest that further research should include the utilization of crude glycerol as a carbon source and optimization of composition of such media and cultivation conditions in order to improve production of antimicrobial substances using Bacillus subtilis ATCC 6633.

2018 ◽  
Vol 33 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Zorana Roncevic ◽  
Ivana Pajcin ◽  
Dragoljub Cvetkovic ◽  
Sinisa Dodic ◽  
Jovana Grahovac ◽  
...  

Biological control is one of the best alternatives to pesticides as it avoids their weak points in plant disease control. In this study, the composition of cultivation medium for production of bioactive compounds by Bacillus subtilis ATCC 6633 was optimized. The produced bioactive compounds were tested against a phytopathogenic Penicillium sp. known for infesting different agricultural products and causing substantial crop losses. Antimicrobial activity assaying was carried out using the diffusion-disc method, and inhibition zone diameters were measured as direct indicators of antifungal activity. The response surface methodology (RSM) was used to evaluate the effects of different contents of initial nutrients (glycerol, NaNO2 and K2HPO4) in cultivation medium on inhibition zone diameter. Optimization was carried out using the desirability function method in order to maximize bioactive compounds yield and to minimize residual nutrients contents. The optimized concentrations of the selected nutrients in cultivation medium for production of bioactive compounds were: glycerol 20 g/l, NaNO2 1 g/l and K2HPO4 15 g/l.


2014 ◽  
pp. 247-258 ◽  
Author(s):  
Zorana Roncevic ◽  
Jovana Grahovac ◽  
Damjan Vucurovic ◽  
Sinisa Dodic ◽  
Bojana Bajic ◽  
...  

The biocontrol agents are a very promising alternative to synthetic pesticides that are presently used to control plant diseases caused by phytopathogenic microorganisms. Members of the Bacillus genera are soil bacteria that produce significant quantities of agriculturally important bioactive compounds. Production of these compounds can be improved by changing the nutritional and environmental conditions. The aim of this study was the optimization of medium composition, using response surface methodology, for the production of compounds effective against Xanthomonas campestris ATCC 13951 by Bacillus subtilis ATCC 6633. To study the production of antimicrobial compounds by selected Bacillus strain, the producing microorganisms were cultivated on nutrient broth. The inhibition zone diameter of 18.0 mm obtained by the diffusion-disc method indicated that the used Bacillus subtilis strain produces compounds with antimicrobial activity against Xanthomonas campestris ATCC 13951. To optimize the composition of the cultivation medium in terms of glycerol, sodium nitrite and phosphates content, experiments were carried out in accordance with Box-Behnken design, and optimization of multiple responses was performed using the concept of desirability function. The developed model predicted that the maximum inhibition zone diameter (26.23 mm) against tested phytopathogen is achieved when the initial content of glycerol, sodium nitrite and phosphate were 50.00 g/L, 2.85 g/L and 11.00 g/L, respectively. To minimize the consumption of medium components and costs of effluents processing, additional optimization set was made. The techno-economic analysis of the obtained results has to be done to select optimal medium composition for industrial production of antimicrobial compounds.


2021 ◽  
Vol 50 (2) ◽  
pp. 219-226
Author(s):  
Abdul Haq ◽  
Alam Khan ◽  
Zulfiqar Ali Malik ◽  
Mushtaq Ahmed ◽  
Samiullah Khan ◽  
...  

Antimicrobial activities of deoiled seed kernel (mechanically pressed), fruit coat and seed coat of Jatropha curcas Linn. collected from two regions (Bannu and Peshawar) of Pakistan were investigated. The antimicrobial activities were carried out against Klebsiella pneumoniae (ATCC 43816), Escherichia coli (ATCC 10536), Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633) and two clinical fungal isolates Aspergillus fumigatus and Candida albicans using agar well diffusion method. The antibacterial activities of Peshawar sample were found to be higher than Bannu, against selected strains. While antifungal activities of both samples were similar. Highest zone of inhibition 31.5 ± 0.7 mm was exhibited by n-hexane extract of deoiled seed kernel of Peshawar sample against Bacillus subtilis (ATCC 6633). The minimum inhibitory concentration of ethanolic extracts of deoiled seed kernel and seed coat of Peshawar sample was 31.25 - 25 mg/ml. Whereas, minimum inhibitory concentration of ethanolic and n-hexane extracts of Bannu sample was 62.5 - 125 mg/ml. The results suggested that antimicrobial potential of J. curcas Linn. varied with geographical distribution. The investigation of different varieties of medicinal plants belonging to the same species will greatly enhance the chances of best pharmaceuticals discovery. Bangladesh J. Bot. 50(2): 219-226, 2021 (June)


Author(s):  
Mihaela DUMITRU ◽  
Mihaela HĂBEANU ◽  
Cristina TABUC ◽  
Ștefana JURCOANE

This study aimed to evaluate some probiotic properties of Bacillus subtilis ATCC 6051a. The phenotypic profile, resistance to pH by simulated gastric juice (pH 2 and 3), bile salts by simulated intestinal fluid, survivability (%), heat and antibiotics tolerance were investigated. The strain is a Gram-positive, rod-shaped bacteria, arranged in short chains or in small irregular pairs with the ability to produce spores. Good viability at pH 2 and 3, with a survival of more than ≥80%, was found. In the presence of bile salts 0.3%, over 4 h, the strain exhibited a survival ≥85%. At 80°C, for 120 min., the strain showed good growth (9.04 log CFU/ml). Results were sensitive to most antibiotics, with a highly susceptible (between 16 – 25 mm) to erythromycin, clindamycin, amoxicillin, chloramphenicol, ciprofloxacin, amikacin and kanamycin. The strain was found to be sensitive to vancomycin, gentamicin, and tetracycline. The present research demonstrated that Bacillus subtilis ATCC 6051a can survive under gastrointestinal conditions, which involves them to future in vitro and in vivo probiotic studies.


2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Karen Tatiana Chávez Arteaga ◽  
Jefferson Javier Guato Molina ◽  
Jorge Luis Rodríguez Acosta ◽  
Ángel Virgilio Cedeño Moreira ◽  
Ricardo Fernando Romero Meza ◽  
...  

El empleo de bio-controladores en la agricultura beneficia los aspectos fisiológicos en plantas, a diferencia de la constante aplicación de pesticidas en el cultivo del banano ha ocasionado la pérdida de la sensibilidad en M. fijiensis, reduciendo la microbiota del suelo. El objetivo se enfocó en caracterizar el potencial antagónico de las PGPR en inhibición de germinación de ascósporas y desarrollo micelial de M. fijiensis. Se realizaron cultivos monospóricos de M. fijiensis e identificado por PCR. Se evaluaron los extractos celulares de Pseudomonas putida PB3-6, Klebsiella variicola BO3-4, Enterobacter asburiae BA4-19, Serratia marcescens PM3-8, Enterobacter asburiae PM3-14, Pseudomonas protegens CHA0, Pseudomonas fluorescens WCS417, Pseudomonas veronii R4 y Bacillus subtilis ATCC 5540 para sus evaluaciones antagonistas: a) Inhibición del tubo germinativo de las ascósporas al 2% y b) Desarrollo micelial al (2 y 10 %). La PCR empleado en la identificación de M. fijiensis se confirma el producto de amplificación de 1018 pb. El factor antagónico de los extractos celulares al 2 % de PM3-14 y CHA0 inhibe sobre el 80 % al desarrollo de los tubos germinativos. La inhibición al desarrollo micelial del extracto celular al 2 %, de CHA0 logró una efectividad del 54 % y las cepas (PM3-8, PM3-14 y BA4-19) con (32, 26 y 26 %). Al 10 % del extracto de la cepa PM3-8 inhibe el desarrollo micelial con niveles de turbidez de 0,47 (OD600nm). El empleo de estos bio-controladores en la agricultura ofrecerá una alternativa para beneficiar en la reducción del uso de agroquímicos


2021 ◽  
Vol 49 (2) ◽  
pp. 174-180
Author(s):  
Yinuo Fei ◽  
Yan Shao ◽  
Weiwei Wang ◽  
Yatian Cheng ◽  
Boyang Yu ◽  
...  

2010 ◽  
Vol 165 (3) ◽  
pp. 183-189 ◽  
Author(s):  
Prakash M. Halami ◽  
Torsten Stein ◽  
Arun Chandrashekar ◽  
Karl-Dieter Entian

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