Biotechnology
Morahem Ashengroph; Somayeh Fattahi
Abstract
Introduction: Silver nanoparticles (AgNPs) are used in a variety of industries, including coatings, disinfectants, water purification, and medicine, due to their small size and unique physical and chemical properties. To avoid the use of chemicals, extracellular biosynthesis of AgNPs using fungal systems ...
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Introduction: Silver nanoparticles (AgNPs) are used in a variety of industries, including coatings, disinfectants, water purification, and medicine, due to their small size and unique physical and chemical properties. To avoid the use of chemicals, extracellular biosynthesis of AgNPs using fungal systems is an appropriate method. In this study, the extracellular biosynthesis of AgNPs by the resting cell of the fungus Aspergillus niger ZRS14 was investigated, and the synthesis process was optimized using Taguchi's statistical method. Methods: The effect of biomass parameters, incubation time, pH and silver nitrate concentration in three levels was performed using Qualitek-4 software. The characteristics of the synthesized AgNPs were determined by spectroscopic analysis including UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM). Results and discussion: The results showed that the selected strain under optimal conditions including 2 mM silver nitrate, pH 6, temperature 32 ◦C, and after 72 h incubation, spherical silver nanoparticles with an average size of 24 to 38 nm in extracellular form synthesized under resting cell strategy. Because of the coating of fungi-secreted proteins, synthetic spherical elemental AgNPs have a crystalline nature, a small size, and high stability.
Herbal
Masoud Haidarizadeh; Fatemeh Alijani; Morahem Ashengroph; sajjadd atashi
Abstract
Introduction: Identifying and introducing new natural antimicrobial compounds against pathogenic agents is of concern to researchers. The present study was conducted with the aim of comparing the chemical compounds, antimicrobial and antioxidant effects of black and green tea. Methods: Aqueous and methanolic ...
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Introduction: Identifying and introducing new natural antimicrobial compounds against pathogenic agents is of concern to researchers. The present study was conducted with the aim of comparing the chemical compounds, antimicrobial and antioxidant effects of black and green tea. Methods: Aqueous and methanolic extracts of black and green tea leaves were prepared and the compounds of the methanolic extracts were identified by GC-Mass, antibacterial effects were measured by the disk diffusion method, the minimum inhibitory concentration (MIC) the antioxidant property by the DPPH method. Results and discussion: Caffeine is the main component of green and black tea extracts, and its amount is 82.97% and 86.25% in these extracts, respectively. The minimum inhibitory concentration of green tea extract against Escherichia coli, Staphylococcus aureus, and Pseudomonas syringae is significantly three times higher than that of black tea extract. The inhibitory capacity of green tea extract against Xanthomonas campestris and the inhibitory capacity of black tea extract against Pseudomonas syringae is significantly higher than the other bacteria. Many of the effects related to green and black tea can be considered related to the relatively high capacity of inhibiting free radicals. The results of this research showed that the free radical and antioxidant capacity of green tea is significantly one and a half times higher than black tea. The inhibitory ability of the extract against plant pathogens is relatively and significantly higher than human pathogens. Different products and perhaps the waste of black tea and green tea can be used to control harmful microorganisms.
Morahem Ashengroph; Sina Daj
Abstract
Introduction: This study aimed to isolate and identify the silver-resistant bacteria and investigation on their potential in the biological synthesis of silver sulfide nanoparticles (Ag2SNPs). Methods: Preliminary characterization of the Ag2SNPs was carried out using visual observations and UV–Visible ...
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Introduction: This study aimed to isolate and identify the silver-resistant bacteria and investigation on their potential in the biological synthesis of silver sulfide nanoparticles (Ag2SNPs). Methods: Preliminary characterization of the Ag2SNPs was carried out using visual observations and UV–Visible spectroscopy. Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) was used to determine size, morphology, and elemental analysis of the nanoparticles. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to determine the functional groups that are involved in the bioreduction of silver sulfate into Ag2SNPs. Results and discussion: Based on the results, Bacillus safensis strain GMS10 with highest tolerance to silver sulfate (50 mM) was able to synthesize spherical shape of Ag2SNPs with an average size diameter of 22.2 nm under optimized conditions (1 mM silver sulfate, 15 g/L biomass) after 36 hours incubation. This study is the first report on the synthesis of Ag2SNPs using B. safensis.
Herbal
Masoud Haidarizadeh; Mahdieh Hemati; Morahem Ashengroph
Abstract
Introduction: Rosemary (Rosmarinus officinalis L.) is a valuable medicinal plant. This study aimed to compare the chemical composition and antimicrobial effects of rosemary metabolic extract and essential oil against plant and human pathogens. Methods: The compounds of methanolic extract and rosemary ...
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Introduction: Rosemary (Rosmarinus officinalis L.) is a valuable medicinal plant. This study aimed to compare the chemical composition and antimicrobial effects of rosemary metabolic extract and essential oil against plant and human pathogens. Methods: The compounds of methanolic extract and rosemary leaf essential oil were identified by GC-Mass and the antibacterial effects of essential oil and extract were measured by disk diffusion method and the minimum inhibitory concentration (MIC) of rosemary essential oil and extract was measured. Analysis of variance and Duncan's test were used for statistical evaluation of data.Results and discussion: Alpha-Pinene, Verbonone, Bornyl acetate, Camphor, Limonene, Caryophyllene, beta-pinene, beta-Myrcene, L-borneol, Camphene are the main constituents of extract and alpha-pinene, camphor, bornyl acetate and eucalyptol, Camphene, Caryophyllene, Limonene, beta-pinene were the main essential oil of rosemary leaf. Rosemary extract showed the highest and lowest inhibitory effect against Escherichia coli and Xanthomonas compestris. In the case of Staphylococcus aureus, Pseudomonas syringe, and Xanthomonas compestris, the results show that the essential oil has the same inhibitory ability against these three strains, and the ability of the extract to inhibit human pathogens is significantly higher than that of plant pathogens. Rosemary extract and essential oil can be used as a solution to eliminating plant and human diseases.
Marahem Ashengarf; Eraj Nahvi; Jahanshir Amini
Abstract
In the recent years, the use of microbial biotransformation processes to achieve specific properties of vanillin and access to the natural vanillin origin has been a lot of attention. In the present study, Taguchi method was employed for optimizing the biotransformation of isoeugenol to vanillin under ...
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In the recent years, the use of microbial biotransformation processes to achieve specific properties of vanillin and access to the natural vanillin origin has been a lot of attention. In the present study, Taguchi method was employed for optimizing the biotransformation of isoeugenol to vanillin under resting cells of native isolate Psychrobacter sp. strain CSW4. Five factors, i.e. initial isoeugenol concentration, initial dry biomass, co-substrates (glycerol, yeast extract and tryptone), initial NaCl concentration and metal ions (Cu, Zn and Co, were selected and experiments based on an orthogonal array layout of L18 were performed. Vanillin produced in the biotransformation reaction mixture was analyzed by HPLC method. Optimization of the process by Taguchi method showed that highest impact factors with importance priority of NaCl concentration, initial isoeugenol concentration, glycerol as substrate, cobalt ion and initial dry biomass were determined as optimum conditions for the biotransformation isoeugenol into vanillin, respectively. Under these optimized conditions, the highest vanillin concentration (1.016 g/L) obtained after 24-h reaction biotransformation. The molar yield of vanillin produced from isoeugenol was 43.8 %. Results of this study indicate that if optimization of medium composition is performed to balance the cell growth and vanillin amount, reasonable yields of vanillin have been achieved, without addition of any toxic organic solvent or other chemicals which increase the cost of production.
