مقالات رزومه دکتر سلمان احمدی

Thymus vulgaris and silver Nanoparticles has been demonstrated. Each of these agents for maximum impact requires a high concentration of substances affecting microorganisms. Assuming an anti-microbial agent with low concentration and in combination with other anti-microbial agents as the initial impact or more, A study to evaluate the effect of ethanol extract of propolis interference, Thymus vulgaris essential oil and silver nanoparticles on gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae, Listeria monocytogenes) and Gram-negative bacteria (Proteus mirabilis, Klebsiella pneumonia and Pseudomonas aeruginosa) and on Candida albicans was performed. Microbial used in this study are taken from Iranian Research Organization for Science and Technology. Propolis is collected from different area of west Azerbaijan beehives. The ethanolic extract of propolis have prepared after 3 days. The interfering effects of these agents are evaluated by Micro-broth dilution method on Muller Hinton Broth in the presence of gentamicin as positive control for bacteria and Nistatin against Candida albicans. Acquired Minimum Inhibitory Concentration (MIC) show the effective interfering of these agents. The results of the Minimum Inhibitory Concentration (MIC) of propolis extract with silver nano particle on Klebsiella pneumonia was 25 µgr/ml, on Streptococcus pneumonia, Pseudomonas aeruginosa and Candida albicans was 50µgr/ml and on Staphylococcus aureus, Listeria monocytogenes and Proteus mirabilis was 100 micrograms per milliliter. MIC of Thymus essential oil with silver nanoparticles on Klebsiella pneumonia and Pseudomonas aeruginosa was 50µgr/ml, on Staphylococcus aureus, Streptococcus pneumonia and Candida albicans was 100 µgr/ml and on Listeria monocytogenes and proteus mirabilis was 200 micrograms per milliliter.

The basis of this research is based on sampling of different parts of Badab Surt Sari spring, including water, soil and sludge. The effect of parameters such as pH, contact time, amount of bacterial biomass and initial concentration of nickel metal ion on the sorption rate was investigated. The final equilibrium time in this experiment was eight hours, but in the first half hour the maximum absorption was made and the number eight is related to the optimal pH. The ion removal isotherm follows the Langmuir model equation and the maximum adsorption capacity of the metal ion was 0.51 mmol/g, Langmuir constant is 49.01, R2 was about 0.994. The use of bacterial biomass without and with metal by means of FT-IR showed that the groups involved, including carboxyl, hydroxyl and the amine. The results indicate that this isolate of rod-shaped bacterium, medium gram-positive filament, containing catalase, methyl red positive, has no motility and belongs to the genus Virgibacillus based on 16 S rDNA gene analysis. The adsorption capacity of nickel metal is very significant in the initial minutes and therefore, the use of the studied bacteria is appropriate in industry and biotechnological processes. The ions studied were adsorbed in the early stages when they were inactive, then in the secondary stage they were actively adsorbed slowly. Therefore, this bacterium has the ability to absorb metal in both live and dead forms.

The synthetic dyes pollution has turned out to be one of the most important environmental problems. Approximately 10000 different dyes and pigments are used industrially and over 0.7 million tons of synthetic dyes are produced annually, worldwide. Synthetic dyes are extensively in the textile dyeing, leather tanning, paper, food and medicine industries. The majority of these dyes are either toxic to flora and fauna or mutagenic and carcinogenic. The disposal of these wastes into receiving waters cause damage to the environment. Therefore, removing them from environment is imperative various methods for physical and chemical decolorization of dyes in wastewater but these methods are rather costly and sometimes product hazardous by-products. In recent years, biodegradation approach of its cost-effectiveness and safe method. In this method, microorganisms, particularly bacteria are used for removing dyes. The goal of microbial treatment is to decolorize and detoxify the dye-contaminated effluents.

In this study, bacillus albus bacteria were isolated Mazandaran industrial wastewater used as an example of gram-positive bacteria. Decolorization by these bacteria was investigated by a system which contained both medium and dye. The effects of operational parameters of indigo carmine including time, initial dye concentration, temperature, pH, shaking/non shaking, aerobic/anaerobic were tested. Ethics code: IR.UMZ.REC.1397.106

The results demonstrated that over a period of 54 h, at 50° C, 100 mg/l of concentration and pH=10, maximum decolorization of 95 percent was performed.

The present study confirms high effectiveness of bacillus strains in dye removal. The main experiment was focused on decolorization of indigo carmine in aeration conditions.

Environmental pollution with toxic and heavy metals has been a major problem in recent decades. Therefore, the removal of these pollutants from the environment is very important.

In this study, the biosorption of hexavalent chromium (Cr+ 6) was investigated by brown alga Sargassum ilicifolium. The absorbance of Cr+6 solutions at 540 nm was obtained by UV-VIS. Also, the effective parameters in absorption such as initial metal concentration, amount of algae, pH, temperature, and contact time were investigated. The Langmuir and Freundlich isotherms were used to study the equilibrium studies.

In these conditions, the maximum adsorption capacity was 203 mg/g of Sargassum ilicifolium. Laboratory data with the pseudo-second-order kinetics were described better. Using Response Surface Methodology (RSM), optimum conditions of maximum adsorption capacity were determined at pH 2, adsorbent content of 0.2 g/l, initial metal concentration of 200 mg/L at 25 °C, and the equilibration time of 7 h.

The results showed that the Freundlich isotherm was more suitable for describing the system. Thermodynamic studies have also shown that the process was exothermic and spontaneous and increased with time due to disorder. Due to the functional groups present in the algal cell wall, part of Cr+6 was reduced to Cr+3 and Cr+3 that were remained in solution. Fourier transform infrared spectroscopy of (FT-IR) showed that amino, carboxyl, sulfonic acid, and hydroxyl groups played a major role in the process of chromium uptake by Sargassum ilicifolium.

Because of the increasing resistance of pathogenic bacteria to common antibiotics, the new generation of researchers sought antimicrobial agents with plant origin as alternative medicine. Oregano is from Lamiaceae family and coriander is from Apiaceae family and has antimicrobial properties. This study aimed to investigate and compare the inhibitory effects of alcoholic extracts of coriander and oregano plants on Staphylococcus aureus, Klebsiella and Salmonella. 1000 ml of alcohol poured round-bottom flask, then the target plant (200-300 g of dried powder of plant) put into envelopes of filter paper and envelopes was placed in a distillation device. After 24-48 hours the obtained alcoholic extract was placed in the oven. DMSO was used to provide different concentrations of ethanol extract. The concentrations of 31/25 and 62/5 mg / ml of alcoholic extract of oregano and concentrations of 62.5 and 125 mg / ml coriander were able to inhibit and kill Staphylococcus aureus and weren`t able to inhibit and kill Salmonella and Klebsiella respectively . Although the clinical application of plant extracts and essences seems valuable due to fewer side effects compared to conventional therapeutic agents, in order to clinical application of plant extracts of oregano and coriander, more research about the mechanism of action of effective components of this plant on the microbial agents is needed.

The aim of this study was to investigate the effects of lavender and rosemary essential oil has antibacterial. Essential oil sample after drying in the shade, to hydrodistillation using a Clevenger apparatus were isolated. The antibacterial effects of Han dilution preparation were evaluated by disc diffusion method. In order to standardize the method of antibiotic disks and ATCC bacteria were used. Results showed that the interactions between plants and diluted in a dilution of 1, 2/1 and 4/1 deterrent effect of lavender plants on five different bacteria than the rosemary plant more meaningful. As the diameter of growth inhibition compared the interactions between bacteria and dilution of the plant showed the highest inhibitory effect on oil dilution 1 is P.mirabilis Comparison of the effects of essential oils of lavender and rosemary together on five different bacteria showed that dilution of 1, 2/1 and 4/1 lavender oil P.mirabilis maximum inhibitory effect on bacteria other than its deterrent effect Rosemary plant was the most significant. Determination of MIC and MBC of lavender and rosemary essential oils showed a bacteriostatic effect on bacteria than similar E.fecalis .The bactericidal effects on all bacteria, but bacteria S.epidermis essence is the same. Evaluation of disk diffusion method in comparison with antibiotic discs, the effect of the plant compared to gentamicin disk Streptomycin against five strains of five different bacteria showed. The results of this study and other studies show that the essence of medicinal plants can be used instead of chemical drugs to treat the infection.

  Today, the ability to produce hydrolases enzyme that are active in high salt concentrations is considered a new approach to the use of halophilic bacteria in biotechnology. The aim of this study was the screening and isolation of extracellular lipase producing halophilic bacteria Marinobacter sp. S-14 isolated from Badab-e Surt Hypersaline spring. In this experimental study, 42 pure bacterial colonies were isolated from different samples of water, soil, sediment, and sludge from a hypersaline spring with a screening technique on the specific culture medium of halophilic bacteria. The isolate S-14, which showed the highest lipase activity, was selected for the identification by biochemical methods and 16S rRNA gene analysis. In order to optimize the growth conditions of the isolate, considering the maximum time of bacterial growth (72 hours), temperature, salt concentration, pH, carbohydrate, and amino acid intake were examined. The results were edited by Chromas pro 2.1.1 software, and compared with EzTaxon database. Strains that were more similar to the isolate were identified. Sequence analysis of 16S rRNA were performed by BioEdit 7.1.9, Clustal-2X 2.1, and MEGA 6, and the phylogenetic tree was drawn by the neighbor joining algorithm. The isolate S-14 had 99% similarity to Marinobacter flavimaris and Marinobacter adhaerens. The isolate had optimum growth in 5% NaCl concentration, 35°C, and 7.0 acidity. The isolate S-14 can be an appropriate candidate to produce extracellular lipase enzyme and can utilize Fructose and Phenylalanine as a sole source of carbon and energy.

The use of medicinal plants to treat infections is an old method¡ having antimicrobial properties that can be common problems in the use of antibiotics to restore. Thus the aim of this study¡ antibacterial effects of essential oils of rosemary plant was on five different bacteria in vitro. Essential oil samples after drying in the shade plant¡ using steam distillation and were isolated using distillation.
An antibacterial effect of this plant by successive dilution and disk diffusion methods was evaluated. In order to control and standardized methods of antibiotic discs and standard bacterial strains were used.
Findings: Based on the results¡ P. mirabilis and E.fecalis the most sensitive and most resistant bacteria to the dilution ratio of 1¡ ½ and ¼ were essential but the most sensitive E.fecalis and E.coli bacteria to dilution of 1/8 ¡ 1/16¡ 1/32 and 1/64 had. The evaluation results o disk diffusion method with antibiotic disks¡ the effect of the plant compared with Gentamicin disks and streptomycin¡ showed against five strains of S.aureus ATCC1885¡ S.epidermidis ATCC2405¡ E.fecalis QTCC2321¡ E.coli ATCC1652¡ and P.mirabilis ATCC 2601.
Discussion & The results of this study show that plant oils can replace for chemical drugs to treat infections. Of course all of this oil should be carefully evaluated in vivo and in vitro.

Toxic metal pollution is effluents from hospitals and factories. Remove them from the environment is important. Iranian Research Organization for Science and Technology of yeast Saccharomyces carlsbergensis PTCC 5051, and received as a lyophilized culture YEDPA environment and then the proliferation of malt extract broth is used. In this study, the effects of parameters such as pH, temperature, kinetics and adsorption isotherm nickel and zinc were determined by Saccharomyces. Maximum amount of nickel and zinc uptake in the pH range 5/5, and 6 was respectively. Kinetic studies showed that the biological uptake of nickel by biomass on Saccharomyces was quickly removed and most of the first test was done in less than 30 minutes. Adsorption of nickel and zinc were determined by Saccharomyces active and in active. Uptake by yeast is more active. Nickel and zinc uptake by Saccharomyces inactivated by autoclaving or sodium azide and di-nitro phenol has been investigated. Maximum amount of nickel and zinc absorption were 0.65 and 0.47 mmol g. Remove toxic heavy metals from wastewater by the yeast Saccharomyces hospitals is high performance.

Today the cells immobilization is a suitable method for reusing microorganisms and protecting them from direct changes in the physico-chemical factors in the environment. In this study, Bacillus cells were immobilized on calcium alginate. Among the methods immobilization ways, entrapment was used and on the other hand the drop method was used from the immobilization ways. Also, after producing fine Bacillus containing alginate, a packed bed reactor, was used to remove the metal nickel. This study showed that uptake of Nickel by Bacillus fixing calcium alginate was more compared with free Bacillus cell and bacteria-free calcium alginate. The percentage of the nickel uptake from the solution by calcium alginate, free bacillus and calcium alginate containing Bacillus are respectively 17.5, 29.5 and 47.5 percent. Discussion and By accepting that active groups of Bacillus have a major role in the uptake of toxic metals and most notably are the alginate carboxylic groups and the organisms containing these groups or used directly free of macromolecules containing these groups can be used.

Amongst the environmental problems, environmental pollution by heavy metal can be pointed. The aim of this work is to investigate adsorbing Cadmium (II) a brown alga Fucus serratus and its uptake by gram-positive bacteria Bacillus sp. Biological methods in comparison with conventional chemical and physical methods have higher efficiency. In this study, isotherm and kinetics of cadmium (II) uptake by bacteria and algae in batch reactor is studied. Langmuir equation based on the maximum rate of uptake of cadmium (II) in bacteria and algae is achieved. The bacillus sp selected in Tehran, and algae brown Fucus serratus harvested from Ponic city in ocean Atlantic in France. This study has shown cadmium (II) uptakes, equilibrium time for algae is about 240 minutes and for bacteria is about 10 minutes respectively. The adsorption equilibrium date was well described by Langmuir equation. The maximum capacity has been extrapolated to 0/45, 0/85 mmol /g for bacillus and F. serratus respectively. All these observation indicate that, this biomass (alga) could be a suitable sorbent for the removal of cadmium from wastewaters.

The heavy metal pollution has become one of the most important environmental problems. Heavy metals are the most important environmental pollutants، especially for human health and aquatic systems are a serious threat. Iranian Research Organization for Science and Technology of yeast Saccharomyces carlsbergensis PTCC 5051، and received as a lyophilized culture YEDPA environment and then the proliferation of malt extract broth is used. The effects of pH، temperature، kinetics and isotherm of lead on metal uptake were evaluated by the SC. Absorption maximum at about pH 5; the optimum temperature was 25 degrees Celsius. A kinetic study showed that batch biosorption of lead to rapid removal by the biomass of Saccharomyces was the first test was done in less than 30 minutes. Method using FT-IR، surface functional groups of fungi were identified. With active and passive absorption of lead by Saccharomyces has revealed more attracted by the yeast is active. With yeast and control yeast on the autoclave، the pre-treated with sodium azide and 2 and 4 DNP nitro phenol showed that claims of capturing، respectively، 0/68، 0/12، 0/44 and 0/48 mmol g was obtained. Results showed that، even using the passive yeast are suitable for the absorption of lead.

The aim of this work was to investigate Pseudomonas sp. as biosorbent, for the fixation of nickel ions in batch reactor. Pollution of the environment by toxic metals is a major environmental problem. In a first step, biosorption kinetics and isotherms have been performed at pH 5.0. The equilibrium time was about 5 min and the adsorption equilibrium data were well described by the Langmuir`s equation. The maximum capacity has been extrapolated to 6.44 mg.g-1. The release of nickel ions, from Pseudomonas sp. by desorption agent such as nitric acid, has been studied. Finally the effects of biomass form, effect of pH values, were studied. These results indicate that Pseudomonas sp. is an excellent candidate for use in reactor to remove nickel ions from polluted aqueous effluents.

The heavy metal pollution has turned out to be one of the most important environmental problems. Due to their high stability in the presence of large amounts of wastewater factory، water treatment is necessary. In this study، Pseudomonas bacteria were isolated Ilam Town industrial waste water used as an example of Gram-negative bacteria. And Bacillus was isolated from desert dust Maranjab Kashan، as representative of Gram-positive bacteria Then، they were investigated in the biological uptake of nickel from aqueous solution in batch reactors. In this research، factors such as the rate of absorption of nickel، the effect of pH solution، metal reproducibility، metal uptake by Pseudomonas and Bacillus، were studied. Adsorption equilibrium time was approximately 10 minutes by Bacillus and the maximum metal uptake by the bacteria was 0. 71 mmol/g dry weight of cells. Discussion and Nickel uptake by Pseudomonas was about 0. 12 mmol/g dry weight cell mass and the equilibrium time was about 5 minutes. Best nickel release factors were Bacillus and Pseudomonas، respectively، of EDTA and nitric acid. The results showed that gram-positive bacterium Bacillus was a better choice for the removal of nickel from contaminated solutions.

The main aim of this work was to investigate Bacillus sp. strain MGL-75 as biosorbent, for the fixation of Cesium ions in batch reactor. Pollution of the environment by toxic metals is a major environmental problem. Biosorption kinetics and isotherms have been performed at pH= 7. The equilibrium time was about 5 min and the adsorption equilibrium data were well followed by the Langmuir`s equation. The maximum capacity has been extrapolated to 48 mg/g. The release of Cs ions, from Bacillus sp bye desorption agents such as EDTA, HNO3, KCl, CaCl2, CH3COOH, KCL, was studied. The effects of culture age of Bacillus and pH values on Cs ions uptake were studied. The effect of Na-Azid as an inhibitor and uncoupling agents such as 2, 4 Dinitrophenol and autoclave on cesium ions uptake also were examined. Results indicated that the Bacillus sp. strain MGL-75 can be an excellent candidate to remove Cesium ions from aqueous solution.