scholarly journals Effects of Arsenic on Laccase Enzyme Activity in Strains of Bacillus Subtilis in Vitro

2019 ◽  
Vol 26 (6) ◽  
pp. 79-85
Author(s):  
Amir Hoseyn Momen ◽  
Saied Shalbaf ◽  
Safora Salahi ◽  
◽  
◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Laccase Enzyme

scholarly journals Potential of some bacteria for biological control of postharvest citrus green mould caused by Penicillium digitatum

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 134-143 ◽  
Author(s):  
Mohammadi Parisa ◽  
Tozlu Elif ◽  
Kotan Recep ◽  
Kotan Merve Şenol
Keyword(s):  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Antifungal Activity ◽  
Mycelial Growth ◽  
Spore Production ◽  
Penicillium Digitatum ◽  
Broth Culture ◽  
Agrobacterium Radiobacter ◽  
Green Mould

Ten bacteria isolate (4 Bacillus subtilis, 2 Bacillus pumilus, 2 Bacillus cereus, 1 Bacillus megaterium, and 1 Agrobacterium radiobacter) were tested in vitro for antagonistic properties against Penicillium digitatum, the causal agent of citrus green mould. The effect of these bacteria was also observed on mycelial growth, spore germination, and spore production of the pathogenic fungus in broth culture. Extracellular enzyme activities of the bacteria were determined. According to the results of in vitro antagonistic tests and enzymes activities, the most promising bacteria were Bacillus subtilis and Agrobacterium radiobacter. These bacteria were tested for disease suppression on lemon fruits. In addition, these bacterial isolates also showed remarkable antifungal activity against the pathogen on lemon fruits. The results of this study showed that Bacillus subtilis and Agrobacterium radiobacter showed remarkable antifungal activity against the pathogen. Chitinase and glucanase enzyme activity of all the tested bacteria was positive. Protease enzyme activity was positive in all tested bacteria with the exception of Agrobacterium radiobacter. In addition, all bacteria inhibited mycelial growth and spore germination (except Agrobacterium radiobacter) of the fungus. Bacillus subtilis, Bacillus cereus, and Agrobacterium radiobacter inhibited spore production in broth culture. Bacillus subtilis and Agrobacterium radiobacter were tested on lemon fruits significantly reduced disease severity. Consequently, these isolates can be used as new biocontrol agents in controlling the post-harvest decay of citrus fruits caused by Penicillium digitatum.

scholarly journals Switchable deep eutectic solvent driven micellar extractive fermentation of ultrapure fibrin digesting enzyme from Bacillus subtilis

2021 ◽  
Author(s):  
Ramya Muniasamy ◽  
Senthilkumar Rathnasamy
Keyword(s):  
Hydrogen Bond ◽  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Gel Filtration ◽  
Deep Eutectic Solvent ◽  
Temperature Response ◽  
Extractive Fermentation ◽  
Two Phase ◽  
Anion Exchange Column

Abstract Fibrinolytic protease (FLP) is a therapeutic enzyme used in the treatment of thrombolytic diseases. The present study proposed the concept of pH-driven swappable micellar two-phase extraction for the concurrent production and purification of FLP from Bacillus subtilis at cloud point extraction. Extractive fermentation was carried out with a pH swap mechanism, and FLP was extracted to the top phase by surfactant deep eutectic solvents (SADES). Shrimp waste was chosen as a sustainable low-cost substrate that yielded a maximum protease of 185 U/mg. Six SDESs were synthesized with nonionic surfactants as hydrogen bond donors and quaternary ammonium salts as hydrogen bond acceptors, and their association was confirmed by H1 NMR. Thermophysical investigation of the synthetic SADES was accomplished as a function of temperature. Response surface methodology for extractive fermentation was performed with the concentration of SADES (35% w/v), Na2SO4 (15% w/v) and pH (6.3) as variables and the enzyme activity (248 IU/mg) as a response. Furthermore, purification using gel filtration chromatography was used to quantify the amount of enzyme obtained in the extraction phase (849 IU/ml). After final purification with an anion exchange column, the maximum purity fold (22.32) with enzyme activity (1172 IU/ml) was achieved. The in vitro fibrinolytic activity was confirmed using a fibrin plate assay.

scholarly journals THE IDENTIFICATION, PRODUCTION AND CHARACTERIZATION OF NATTOKINASE, BACTERIOCIN FROM BACTERIAL SPECIES

2019 ◽  
Vol 2 (4) ◽  
pp. 91
Author(s):  
Lal Krishna
Keyword(s):  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Blood Clot ◽  
Bacterial Species ◽  
Antagonistic Activity ◽  
Bacterial Strains ◽  
Wide Range

The study was aimed at identification, production and characterization of nattokinase, bacteriocin from bacterial species. Nattokinase and bacteriocins finds a wide range of applications in Pharmaceutical industry, health care and medicine. Nattokinase is a highly active fibrinolytic enzyme secreted by Bacillus subtilis and bacteriocins are proteinaceous toxins produced by Lactobacillus to inhibit the growth of closely related bacterial strains. Bacillus subtilis and Lactobacillus isolates shown positive results to microscopic, biochemical analysis.  The nattokinase and bacteriocins were produced by optimizing the media. The enzymes were purified by ammonium sulfate precipitation and HPLC. The enzyme activity for nattokinase was found at 7 mg/ml, pH 8.0 and temperature 48 ºC and the enzyme activity for bacteriocin was found at 3.9 mg/ml, pH 6.5 and temperature 30 °C. Bacteriocins from Lactobacillus showed good antagonistic activity against pathogenic bacteria. Nattokinase from Bacillus subtilis played a significant role in thrombolytic and anti-coagulation at in vitro. The results indicated that the pure enzyme has a potential in dissolving blood clot.

Improved Production of Two Anti-Candida Lipopeptide Homologues Co- Produced by the Wild-Type Bacillus subtilis RLID 12.1 under Optimized Conditions

2020 ◽  
Vol 21 (5) ◽  
pp. 438-450
Author(s):  
Ramya Ramchandran ◽  
Swetha Ramesh ◽  
Anviksha A ◽  
RamLal Thakur ◽  
Arunaloke Chakrabarti ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Pathogenic Fungi ◽  
Fold Increase ◽  
Production Yield ◽  
Yield Enhancement ◽  
Bioactive Metabolites ◽  
Candida Auris ◽  
Media Formulation ◽  
Static Conditions

Background:: Antifungal cyclic lipopeptides, bioactive metabolites produced by many species of the genus Bacillus, are promising alternatives to synthetic fungicides and antibiotics for the biocontrol of human pathogenic fungi. In a previous study, the co- production of five antifungal lipopeptides homologues (designated as AF1, AF2, AF3, AF4 and AF5) by the producer strain Bacillus subtilis RLID 12.1 using unoptimized medium was reported; though the two homologues AF3 and AF5 differed by 14 Da and in fatty acid chain length were found effective in antifungal action, the production/ yield rate of these two lipopeptides determined by High-Performance Liquid Chromatography was less in the unoptimized media. Methods:: In this study, the production/yield enhancement of the two compounds AF3 and AF5 was specifically targeted. Following the statistical optimization (Plackett-Burman and Box-Behnken designs) of media formulation, temperature and growth conditions, the production of AF3 and AF5 was improved by about 25.8- and 7.4-folds, respectively under static conditions. Results:: To boost the production of these two homologous lipopeptides in the optimized media, heat-inactivated Candida albicans cells were used as a supplement resulting in 34- and 14-fold increase of AF3 and AF5, respectively. Four clinical Candida auris isolates had AF3 and AF5 MICs (100 % inhibition) ranging between 4 and 16 μg/ml indicating the lipopeptide’s clinical potential. To determine the in vitro pharmacodynamic potential of AF3 and AF5, time-kill assays were conducted which showed that AF3 (at 4X and 8X concentrations) at 48h exhibited mean log reductions of 2.31 and 3.14 CFU/ml of C. albicans SC 5314, respectively whereas AF5 at 8X concentration showed a mean log reduction of 2.14 CFU/ml. Conclusion:: With the increasing threat of multidrug-resistant yeasts and fungi, these antifungal lipopeptides produced by optimized method promise to aid in the development of novel antifungal that targets disease-causing fungi with improved efficacy.

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