JOURNAL OF BIOTECHNOLOGY
Year:2018 | Volume:9 | Issue:2 |Papers Count:20

Aims: IP3 is a key regulator molecule in the message transmission pathway, and releases calcium into the cytoplasm by binding intracellular IP3R receptors on the surface of the internal calcium stores. The aim of this study was expression, purification, and characterization of IP3-binding domain from human type 2. Materials & Methods: In this experimental study, the pET-28a plasmid of the carrier of the IP3BD gene was transferred to the E. coli expression strain BL21 (DE3) by chemical method. In order to optimize the expression in the bacterial system, the expression was studied in different conditions, and various temperatures such as 16, 18, 20, and 24° C, the different times after incubation, type of inducer, and its different concentrations were investigated. The induced bacteria were purified on the basis of thermal shock through nickel column for chromatography and the purity of the protein was measured through SDSPAGE. The fluorescence emission of IP3-binding domain was measured in the presence and absence of an IP3 ligand at wavelength of 295nm. Findings: Protein did not have a significant expression in LB, TB, and 2xYT environments, and no changes were observed at different times. Expression of bacterial protein at 20° C based on thermal shock of 42° C was higher than in all cases. The purification of the induced bacteria was difficultly repeated due to thermal shock, and the purified samples did not have high concentrations. The fluorescence emission of the protein decreased in the presence of the IP3 ligand. Conclusion: The bacterial expression of IP3-binding domain from human type 2 is weak, but the expression of protein increases with the induction of shock of 42° C.

Aims: Chromium has destructive effects on the environment and various chemical methods have been investigated for removal of Cr (VI), but high cost and environmental problems have led to using biological methods to remove chromium. The aim of this study was to optimize adsorption process of Cr from aqueous solution, using biosynthesized palladium nanoparticles by Spirulina Platensis. Materials & Methods: In this experimental study, palladium nanoparticles were synthesized, using Spirulina Platensis and examined by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) methods. During the process of adsorption of chromium, pH, contact time, initial Cr concentration, and adsorbent dosage to optimization were optimized. Adsorption isotherms for Chromium were also determined on palladium nanoparticles based on Langmuir and Freundlich isotherm models. Findings: The extract of Spirulina Platensis had the ability to synthesize palladium nanoparticles. The maximum removal was obtained at pH=2, initial chromium concentration=0. 1mg/l, contact time=20 minutes, and adsorbent dosage=0. 5g/l, and the removal percentage varied from 68. 9% to 98. 1%. RL for palladium nanoparticles was in the range of 0. 17 to 0. 95, showing that Langmuir model was suitable for adsorbent. Conclusion: Biosynthesized palladium nanoparticles by Spirulina Platensis high efficiency in removing chromium in aqueous solutions.

Aims: In recent years, magnetotactic bacteria and their magnetic nanoparticles (magnetosomes) were considered in different fields of science, including medicine, biotechnology, and nanobiotechnology due to their novel and unique magnetic properties. The present study was performed with the aim of evaluating the effect of temperature and reducing agent on labeling of magnetosomes with 188Re and biodistribution of labeled magnetic nanoparticles. Materials & Methods: In this experimental study, Alphaproteobacterium MTBKTN90 and sonication extraction method were used for the extraction of magnetic nanoparticles. After bacterial lysis, the magnetic nanoparticles produced by electron microscope were investigated and tin (II) chloride, as reducing agent, was used to check the labeling efficiency and rats were used to examine the biodistribution of the labeled magnetosomes. Findings: The highest efficiency in magnetosome labeling experiments was 11100kBq in the initial activity, which decreased with increasing activity. The increase in temperature did not have much effect on increasing the labeling efficiency. The labeling value in the absence of a reducing agent was 721. 5kBq, while at a concentration of 2mg of this agent, the labeling value increased to 10745. 91kBq. After the injection of magnetosomes through the sublingual vein of the rat, the magnetosomes accumulated in the liver. Conclusion: Magnetosomes extracted from Alphaproteobacterium MTB-KTN90 have a high potential for labeling by 188Re. Increasing temperature does not affect the labeling efficiency, but tin (II) chloride is a very important factor in optimizing the labeling efficiency, and the highest accumulation of magnetosomes labeled with 188Re after injection is in the liver of the rat.

Aims: Computation of the field distribution and the penetration of electromagnetic fields induced in the body and biological tissues are one of the major issues discussed in the bioelectromagnetic field; with access to the geometry of the cell and its organelles, the contribution of each component to the field's reception and the field distribution as well as the computation of impedance can accurately be estimated. The aim of this study was to create 3D geometric models of cells and organelles for bioelectromagnetic simulations. Materials & Methods: The present study is a computational research study. In this study a complete electrical model for several cell types of the epidermis layer of human skin with its organelles was created by SAVI 1 software and innovative new algorithms. In this geometric model, organelles such as mitochondria, Golgi body, melanin pigments, ribosome, lysosome, and intracellular nucleus were considered. The microscopic 2D image was used to create organelles. Findings: The geometric model was created for the organelles and the cellular sample was created for all layers of the epidermis in accordance with reality. The cells of basal cortex were nucleated in cubic form, the cells of spinosum cortex were polygonal and nucleated, the cells of granular cortex were flat and nucleated, and the stratum corneum had complete flat cells without nucleus. Conclusion: Creating 3D geometric model of cells and organelles within it is possible for bioelectromagnetic simulations. This 3D model can be saved in mat, stl, and vox formats and retrieved in SAVI, CST studio, and MATLAB software.

Aims: The production of biofuels has been one of the promising efforts in biotechnology in the past decades. Unicellular cyanobacteria are widespread phototrophic microorganisms that can be suitable chassis for production of valuable organic materials like biofuels. The aim of this study was the reconstruction and modeling of integrated metabolic network of a cyanobacterium to increase the production of biofuels. Materials & Methods: In the present computational study, a software for integrating reconstructed metabolic networks was developed to optimize and increase their efficiency and was named as iMet. First, iMet was used to integrate the 3 pre-reconstructed metabolic networks of Synechocystis PCC6803. In the next step, the reconstructed network was modeled to produce 4 types of biofuels, including ethanol, propanol, butanol, and isobutanol. Findings: The new merged model had 808 reactions and 560 metabolites. The amount of flux or flow in the integrated model was calculated to be 0. 0295 hours per hour. This showed a remarkable increase compared to the previous three models. The cells were divided once every 24 hours. The amount of flux of 4 types of alcohol and their maximum theoretical efficiency increased in the integrated model compared to the previous 3 models. The flux of ethanol production was greater in all models than flux of 3 other alcohols, and the ethanol production reactions were closer to the flow or the central flux of carbon. Conclusion: The analyses of flow equilibrium in the metabolic network coverage show an increase in the production of biofuels and a decrease in the number of blocked reactions in the new model, thereby the efficiency of the developed iMet software is proved.

Aims: Among different nanosystems, polymeric nanoparticles are highly regarded because of their potential to be used as drug carrier. poly(ethylene glycol)-block-lactide-glycolide (PEG-PLGA) is an amphiphilic copolymer that can be used to carry water-soluble drugs and drugs and molecules insoluble in water. PEG-PLGA polymeric nanoparticles can reduce renal filtration and drug toxicity; they are also biodegradable and biocompatible. The aim of this study was to optimize preparation of PEG-PLGA nanoparticles by solvent evaporation method. Materials & Methods: In the present experimental study, PEG-PLGA nanoparticles with a diameter of 150nm and a zeta potential of-10 were prepared by solvent evaporation method. Then, the physicochemical properties of nanoparticles were carefully examined. Findings: By increasing the polymer concentration and the percentage of polyvinyl alcohol, particle size increased. The production of nanoparticles with a concentration of 5mg/ml copolymer, a 2% w/v polyvinyl alcohol concentration, and in a 12: 1 volume ratio showed the best size and superficial load. Morphologically, the nanoparticles were structurally similar and spherical. According to the FTIR spectrum, the peak in 2900-13000cm region was in accordance with the tensile bond C-H in CH3. A strong peak in 1760cm-1 was related to the tensile-CO that showed the copolymer formation. Conclusion: The production of PEG-PLGA nanoparticles in a concentration of 5mg/ml copolymer, 2% w/v of polyvinyl alcohol concentration, and in a 12: 1 volume ratio shows the best size and superficial load; also, the nanoparticles are structurally similar and spherical.

Aims: Adaptation of native bacterial strains in every climate is considerable. Evaluation of native thermotolerant acetic acid bacteria effectively influence their optimal and beneficial use. The aim of this study was to evaluate the characteristics of productive thermotolerant acetic acid bacteria with focusing on Acetobacter sp. A10. Materials & Methods: In the present experimental study, the native thermotolerant strain of Acetobacter sp. A10 was used. For preparation of fresh culture and maintenance of thermotolerant strain glucose yeast extract calcium carbonate was used, which contained 50g glucose, 10g yeast extract, 30g calcium carbonate, and 25g agar per liter. In order to produce acetic acid by the strain of Acetobacter sp. A10, ethanol yeast extract broth culture was used. Effect of initial concentrations of ethanol and acetic acid on the production of acetic acid by Acetobacter sp. A10 was investigated, using a culture meda containing 2% to 9% ethanol and 2% to 9% acetic acid. Findings: This strain could produce 40g/l acetic acid from 4% (WV) ethanol in baffled shake-flasks in 24h under optimized conditions of pH 4, at 33° C, and 150rpm. The strain at 37 ° C was able to produce acetic acid in the presence of a 4% and 8% initial concentration of acetic acid a. The rate of fermentation was 2. 5 times more than mesophilic ones. Conclusion: Acetobacter sp. A10 is active in a different temperature range compared to mesophilic strains and it is able to withstand ethanol and acetic acid to more concentrations. In addition, it has higher efficiency, as well as greater rate and power of fermentation.

Aims: In recent years, according the benefits of chloroplast transformation, the cultivation of transplastomic plants and their products have been increased. Due to their biosafety concerns, their identification and labeling have become more widely considered. The aim of this study was to present an optimal method based on polymerase chain reaction (PCR) and nanobiosensor for detection of transplastomic tobacco plants and compare their sensitivity. Materials & Methods: In the present experimental research, aadA gene as a chloroplast selectable marker was considered to design specific primer and probe. In PCR method, after optimization of aadA gene amplification, its sensitivity was evaluated with different percentages of transplastomic DNA. In nanobiosensor method at first, the labeled aadA probe was immobilized on graphene oxide (GO) and, then, hybridization reaction was optimized to identify target DNA sequence. Findings: The amplification of 800 bp DNA related to aadA gene was observed. The PCR reaction allowed up to 5% DNA transplostomy tobacco to reproduce the aadA gene. In results of nanobiosensor after immobilization of aadA probe on GO, fluorescence emission was quenched and by adding the trasplastomic tobacco, DNA was observed again. In this method, up to 1% transplastomic tobacco DNA, fluorescence emission was significant in comparison with control tobacco plant. Conclusion: The PCR method can detect a transplastomic tobacco plant with 5% DNA sensitivity and detect biomarker sensitivity with 1% DNA sensitivity. The PCR method can detect a transplastomic tobacco plant with 5% DNA sensitivity and nanobiosensor can detect with 1% DNA sensitivity. Therefore, nanobiosensor method is not only a reliable diagnostic method, in addition to the PCR method for detecting transplastomic plants, but also has a higher sensitivity.

Aims: Alchemilla L. genus (Rosaceae) has various biological activities such as anti-inflammatory, anticarcinogenic, antioxidant and antimicrobial. The aim of the present study was to investigate antioxidant activity and free radical scavenging of the extract obtained from Alchemilla persica by percolation, polyphenol fraction, and ultrasonic methods. Materials & Methods: In the present experimental research, Alchemilla persica was used and percolation, polyphenol, and ultrasonics methods were used for extraction and the antioxidant activities of the extracts were determined by different tests, including 1, 1-Diphenyl-2-picrylhydrazyl (DPPH), nitric oxide scavenging activity, Iron chelating activity, and reducing power. Total phenolic and flavonoid content were measured by the Folin Ciocalteu and AlCl3 methods, respectively. The data were analyzed by SPSS 22 software, using one-way ANOVA and tukey test. Findings: In DPPH radical scavenging activity, the polyphenol extract had a significant different with other extracts (p=0. 001). Polyphenolic extract showed higher reducing power than other extacts and Vitamin C (p=0. 001). Percolation extract had higher amounts of total phenolic and flavonoid content than other extracts. Conclusion: Polyphenolic extracts have the highest DPPH, nitric oxide scavenging activity, Iron chelating activity, and reducing power compared to ultrasonic and percolation methods. Aerial parts of Alchemilla persica extracts have high levels of antioxidant activity including phenols and flavonoids.

Aims: In irreversible electroporation process, the membrane of cancer cells is damaged irreversibly by electric pulses of high-intensity field, which in turn leads to cell death. Factors influencing the field distribution include voltage, pulse width, and electric conductivity of tissue. The present study was conducted with the aim of evaluating conductivity changes of liver tissue during irreversible electroporation and calculation of the electric field distribution. Materials & Methods: In the present experimental study, using simulation, the relationship between pulse width and voltage intensity of each pulse was investigated in conductivity changes during irreversible electroporation, and the electric field distribution was calculated. In this simulation, in order to solve the equations, the software COMSOL 5 was used. Needle electrodes were used, and the liver tissue was considered as the target tissue. Eight pulses with the stimulated frequency of 1Hz, pulse width of 100μ s and 2ms, and the intensity of the electric fields ranging from 1000 to 3000v/cm were used as electric pulses. Findings: Conductivity of tissue increased during sending the electrical pulses. The conductivity changes in the tip of the electrodes were more than the area between the two rows of electrodes. As the intensity of the pulsed electric field increased, the tissue conductivity also increased. When the conductivity of the tissue was constant and variable, the maximum electric field intensity was obtained 3879 and 3448v/cm. Conclusion: While electric pulse transmission, tissue conductivity increases. The electric field distribution depends on the conductivity at the desired point and by changing this conductivity due to the electroporation, the electric field distribution also changes and the maximum intensity of the electric field decreases.

Aims: Saffron is one of the plants, whose allelopathic effect of various organs have been reported to affect seed germination of some weed species. The present research was conducted with the aim of evaluating the allelopathic effect of extraction solution of leaves and corms of saffron (Crocus sativus) in phenological stages on seed germination of jimson weed (Datura stramonium). Materials & Methods: In this experimental study, an experiment was conducted to study the allelopathic effects of saffron on jimson weed seed germination at research farm, Tarbiat Modares University Faculty of Agriculture in autumn 2014. The experiment was arranged as factorial split plot in a completely randomized design with 3 replications. The treatments included factorial combination of 2 extract types (water and alcohol), 3 tissue compositions of saffron organs, different concentrations of aqueous, and alcoholic extracts as the main plots and 3 different phonological stages of saffron were considered as sub-plots. One-way analysis of variance was performed through generalized linear model (GLM), using SAS 9. 1 software, and drawing charts was done, using Excel2013 software. Findings: The concentration and phonological stage of saffron had a significant effect on the germination percentage of Datura stramonium, but the main effect of organ type on this trait was not significant. The aqueous extract of saffron did not have significant effect on the germination of Datura stramonium germination at the phonological stage of the daughter corms at a concentration of 2g/l in comparison with other phonological stages, but at a concentration of 4g, it significantly decreased the seed germination. Conclusion: Extract of saffron has an allelopathic potential, and germination traits, including germination percentage and plumule and radicle length of Datura stramonium in different phonological stages of saffron are affected by the aqueous and alcoholic extracts of different organs.

Aims: Heavy metal pollution is a worrisome environmental problem around the world. This study aimed at evaluating the efficiency of spirogyra to remove heavy metals such as chromium (Cr), copper (Cu), and zinc (Zn) from the aquatic environments. Materials & Methods: The present experimental research was carried out on spirogyra of aqueducts in Birjand. The experimental method was considered one-factor-at-a-time. Effect of pH parameters, adsorbent dosage, contact time, initial concentration of Cr, Cu, and Zn at adsorption of heavy metals by spirogyra and Kinetic models, and Langmuir adsorption isotherms, Freundlich, and Temkin were examined. Findings: The highest percentage of Cr (84. 48%) and Cu (76. 85%) removal occurred at pH 3 and 5, respectively with initial concentration of 20mg/l Cr and Cu at 15 and 40 minutes, respectively, in 3g algae biomass. Also, the highest Zn removal efficiency (89. 26%) occurred at pH=5, initial concentration of 20mg/l, and adsorbent dosage of 2g/l over a 20 minutes period. Adsorption of Cr, Cu, and Zn were followed by Langmuir model with correlation coefficient 0. 9983, 0. 9924, and 0. 9977, respectively. According to the kinetics results, the adsorption of Cr, Cu, and Zn were followed by pseudo second model with coefficients of 0. 9922, 0. 9767, and 0. 9953, respectively. Conclusion: Spirogyra has a high ability to remove chromium, copper, and zinc from aquatic environments.

Introduction: Sometimes materials that do not have the ability to penetrate into the membrane will need to be widely entered into the cell. Therapeutic methods are among the methods that sometimes feel this change in permeability when using different drugs and genes. Electroporation (EP) is a new technique that increases the permeability of cell membranes when cells exposed to an external electric field more than a threshold voltage and is used to introduce different non-permanent molecules. The major application of EP in the treatment of cancer combined with chemotherapy drugs such as Bleomycin and Cisplatin is electrochemotherapy. The aim of this study was to review the electroporation of cells, using electric and magnetic fields with approach of cancer treatment. Conclusion: In pre-clinical studies, this method has first been optimized on the animal and cell, and after clinical trials, today, the standard and clinical protocol of electrochemotherapy has been proposed as a safe and effective method for some tumors. This is a simple method with minimal side effects, but in new preclinical studies, with the use of high frequency electrons, low electromagnetic fields, and the use of pulsed magnetic fields, it has been tried to overcome the limitations of this standard method.

Aims: One of the most important areas in medical research is the identification of disease-causing genes, which helps the identification of mechanisms underlying disease and as a result helps the early diagnosis of disease and the better treatment. In recent years, microarray technology has assisted biologists to gain a better understanding of cellular processes. To this end, the application of efficient methods in microarray data analysis is very important. The aim of this study was the introduction of GRAP Gene as Alzheimer’ s disease candidate gene using microarray data analysis. Materials & Methods: In the present bioinformatic study, which was conducted on an Alzheimer's microarray data set containing 12990 genes, 15 patients, and 16 healthy subjects, by combining Fisher, Significance Analysis of Microarray (SAM), and Particle Swarm Optimization (PSO) methods as well as Classification and Regression Tree (CART), a new method was presented for analyzing microarray gene expression data to identify genes involved in Alzheimer's incidence. Findings: The accuracy level of the proposed method was 90. 32% and the interpretation of the results from a biological point of view indicated that the proposed method has worked well; finally, the proposed method introduced 4 genes, of which, until now, 3 genes (75%) have been reported in biological studies as genes that cause Alzheimer’ s disease. Conclusion: In addition to proposing a new feature selection method for the analysis of microarray data, this study has introduced a new gene (GRAP) as a candidate gene related to Alzheimer’ s disease.

Aims: Bordetella pertussis is a gram negative and obligated aerobic bacterium that causes pertussis disease and it is a specific pathogen in human. Pertussis is an acute respiratory infection and leads to death in infants. The aim of this study was to analyze housekeeping genes in Bordetella pertussis vaccine strains by multilocus sequence typing (MLST). Materials & Methods: In the present experimental study, 4 samples of 134 and 509 bacterial strains and 2 standard samples of Tohama I, and 18323 were collected. After biochemical tests, the samples were cultured and separated and the genomic purification of DNA was done by Phenol– chloroform technique and analyzed by MLST. After genome sequencing, the analysis was performed by standard software such as Clustalw 2, MEGA 5. 04, and DNASIS Max 3. Sequence similarity of 16S rDNA gene nucleotides was performed, using BLAST software with sequences recorded in the GenBank genome database to compare and determine the sequences similarity. Findings: Regarding the created bands and the sequence of the game, the housekeeping genes in Bordetella pertussis vaccine strains were approved. The results of the PCR reaction for Pgm, Icd, Gly A, and Tyr B genes showed that all specimens have homogenous genes with a molecular weight of 500bp. Conclusion: Evaluating the housekeeping genes in Bordetella pertussis vaccine strains by MLST vaccine strains (Razi Institute; Iran) correspond with international standard series and no change or deviation has occurred in the studied genes.

Aims: Antioxidants in sesame oil, including tocopherols and sesamin have greatly increased the shelf life of it against heat. Following the increase in the expression of the cytochrome P450 enzyme encoder (CYP81Q1), the content of sesame is increased in different stages of development of sesame seeds. The aim of this study was cloning, sequencing, and bioinformatics study of CYP81Q1 gene of Iranian sesame (Seamum indicum L. ) cultivar. Materials & Methods: In the present experimental research, DNA was extracted from leaves and stems of Karaj1 sesame cultivar and the target gene was amplified by PCR. Gene was cloned in binary vector pBI121 and confirmed by 3 methods, including enzymatic digestion, PCR, and sequencing. Then bioinformatics characterization of this gene was studied and the Ramachandran plot was drawn on the three-dimensional structure of the gene. Findings: Cloning was confirmed. DNA sequencing results confirmed the cloned segment. Molecular weight and predicted isoelectric point of the protein were 57021. 3 Dalton and 8. 46, respectively. The three-dimensional structure of the protein had a good stroke chain. The sequencing result of this gene showed a difference in the 23 nucleotides of this gene in sesame seeds of Karaj 1 (access number KP771974. 1) with a reported sequence in the NCBI gene bank (access number AB194714. 1), which resulted in the sequencing of the CYP81Q1 gene in Iranian sesame (Karaj 1) at this database. Conclusion: Based on nucleotide sequencing, the target gene has 1521 base pairs, and differs from 23 nucleotides with the sample registered at the NCBI World Bank. This gene encodes a protein length of 506 amino acids. This protein is very similar with the registered protein in NCBI.

Aims Sclerotinia is an important fungal disease of sunflower in Iran that affects its yield. The present study was conducted with the aim of evaluating proline content, total protein, and protein electrophoresis pattern in sunflower (Helianthus annuus L. ) in response to sclerotinia (Sclerotinia sclerotiorum) disease. Materials & Methods In this experimental study, proline content, total protein, and protein electrophoresis pattern in sunflower lines (C39 and C100) were compared with control group during different times after inoculation of the lines with the Sclerotinia fungal isolates (SSU107 and SSKH41) under controlled conditions and as a factorial based on completely randomized design (CRD). Separation and isolation of total proteins extracted by sodium dodecyl sulfate– polyacrylamide gel electrophoresis (SDS-PAGE). The date were analyzed by SPSS 22 software, using multivariate analysis of variance and Tukey test. Findings Resistant line C39 in all of the time periods after being infected had higher proline compared with control and other groups. The total protein of all control plants was higher than that of infected plants with both fungal isolates. Fungal infection accumulated low molecular weight proteins in both lines, so that some proteins in the resistant and some proteins in susceptible lines were produced and removed, respectively. Conclusion Resistant line C39 in sunflower infected with fungal isolate SSU107 Sclerotinia sclerotiorum has the highest proline content. Fungal infection, especially in resistant lines, leads to a reduction in total protein levels and the accumulation of low molecular weight proteins in resistant and susceptible lines.

Aims Wheat is one of the most important crops products in Iran. Considering the role of nanotechnology in the production of crops, the study of the effect of nanoparticles on its growth processes is very important. The aim of this study was to investigate the effect of silver nanoparticles on germination characteristics of wheat in in vitro situation. Materials & Methods In this experimental study, germination characteristics of 10 wheat cultivars were performed in 4 concentrations including silver nanoparticles, 10000, 5000, 1000, and zero (Control) with 4 replications in factorial design based on completely randomized design. Root and shoots length, root to shoot ratio, germination rate, percentage of germination, time average and index of germination, daily mean germination, seedling emergence and, vigor index were measured. Analysis of variance and Pearson correlation as well as SPSS 18 and Excel 2013 were used to analyze the data. Findings All traits had a significant correlation with each other (p<0. 01). There was a significant difference between cultivars and also between different concentrations of nanosilver for all traits (p<0. 01). Major decomposition and cluster analysis showed the highest level of germination at the control and further at 1000 ppm level. Also, with increasing nanoparticle concentration, the germination characteristics also showed a significant decrease (p<0. 01). Orom and Parsi were the best cultivars because of the highest value of germination characteristics. Conclusion High concentrations of silver nanoparticles have an effect on germinating characteristics and reducing their amounts. There are variations between the wheat cultivars for the studied characteristics. Orom and Parsi cultivars are superior to other cultivars.

Aims Today, crude oil is one of the main sources of energy. The combustion of sulfur-containing compounds in fossil fuels leads to the production of sulfur oxides that has adverse effects to human health and the environment. At the moment, the current method for removal of sulfur is Hydrodesulfurization. The aim of this study was to investigate the effect of magnetic nanoparticles and modified carbon nanotubes as nano-adsorbent on improving the biodesulfurization activity of microorganisms (Rhodococcus erythropolis IGTS8). Materials & Methods In the current experimental study, the nanoparticles were synthesized by chemical co-precipitation and the carbon nanotubes were initially carboxylated. Multi-layer carbon nanotubes were mixed with 95% sulfuric acid and 52% nitric acid (volume ratio 1: 3) and, then, modified by polyethylene glycol. In order to characterize nanoparticles and carbon nanotubes, scanning transmission electron microscopy (STEM), X-ray diffraction, magnetic surveys, analysis of arch Raman, and fourier-transform infrared spectroscopy (FTIR) were conducted. Findings The size of nanoparticles was estimated to be 7-8nm and modified carbon nanotubes showed the highest solubility as well as stability in deionized water for two weeks. The growth of microorganisms in the presence of magnetic nanoparticles and carbon nanotubes compared to their absence increased by 40% and 8%, respectively. Moreover the desulfurization activity of microorganisms in the presence of magnetic nanoparticles and carbon nanotubes showed a significant increase compared to their absence. Conclusion Nanoparticles with adsorption of sulfur compounds increase their availability for microorganisms.

Aims: The effect of crude oil pollutants on water and soil pollution and ecological changes has resulted in several studies on the identification and removal of these pollutants. The biological methods have been highly regarded for controlling this type of pollution due to their optimal performance. The aim of this study was the comparative assessment of crude oil biodegradation by Acinetobacter Calcoaceticus RAG-1 in the presence and absence of biofunctional magnetic nanoparticles. Materials & Methods: In this laboratory research, the amount of degradation of N-decane and Hexadecane were studied, as indices of normal paraffins in crude oil pollutions, by Acinetobacter Calcoaceticus RAG-1 in the optimal conditions, which Emulsan produced. Also, the effect of magnetic nanoparticles of iron oxide coated with two layers of Decanoic acid on the degradation was investigated separately. The independent t-test was performed to examine the significance of the model parameters and the two-way ANOVA was used to examine the goodness of fit. The experiment was done with a fractional factorial design. For statistical analysis of the results, Minitab V. 16 software was used. Findings: The biodegradation of N-decane and Hexadecane were obtained 85% and 86%, respectively, after 60 days. The presence of nanoparticles also led to an improvement in the biodegradation process and an increase of 91% and 89%, respectively. Conclusion: Acinetobacter Calcoaceticus RAG-succeeds in eliminating paraffinic compounds from crude oil with medium chain length. The effect of presence of nanoparticle in the biodegradation of N-decane is greater than that of Hexadecane.