نشریه زیست فناوری دانشگاه تربیت مدرس
سال ششم شماره 1 (پیاپی 9، بهار و تابستان 1394)

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.

Nanotechnology involves technological research and development in spaces at the range of 1 to 100 nanometers, and in this technology, very small and atomic scale particles are created and handled. Plant extracts can be used as a green method for the synthesis of silver nanoparticles. In this study, the biosynthesis of silver nanoparticles was performed using extracts of sesame (Sesamum indicum) seeds. Silver nitrate was added to the seed extract, and then it was incubated at 30 ° C. The effects of three concentrations (1mM, 2mM and 3mM) of silver nitrate on the synthesis of silver nanoparticles were studied. The analyses of absorption spectroscopy UV-Visible, Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD) and Inductively Coupled Plasma (ICP) were conducted to assess the production of nanoparticles. UV-Visible spectroscopy analysis and the peak at 420 nm indicated the occurrence of nanoparticles in the extract. TEM image determined that the nanoparticles were spherical with average size of about 14 nm. XRD analysis showed the nano-crystals synthesized by the extract, and Inductively coupled Plasma (ICP) determined the conversion percentage of silver ion into silver nanoparticle as approximately 99.61 percent.

In this study,we investigated the biosurfactant -producing microorganisms. Samples of the oil wells, , stable and Ilam were collected and transferred to the Scientific and Industrial Research Organisation biotechnology collaboration of 45 strains isolated from the IROST and the best combinations of isolates selected strains produced using different culture conditions were the order of 3M mineral salts medium containing glucose, molasses and Lindhard Taguchi method was used in these experiments, various factors were analyzed. The best conditions are obtained to produce rhamnolipid with medium Lindhard in vitro rate of 8/8 g rhamnolipid and ability emulsification of crude oil, 88 percent of the dry weight of cell 2/2 g, therefore, the intended environment for the production the fermenter was used in the state parameters shaking, C/N ratio and aeration efficiency and maximum production of rhamnolipid 2/14 grams per liter of capacity emulsification of crude oil 2/98 and the dry cell 4/3 g of was 23 % and the highest oil recovery of crude oil saturation in the core when the system is equal to 42% was achieved.

A high population of the sea anemone inhabit in the intertidal zone of the Hormoz Island. The tidal zones generally are characterized by severe environment stresses (vis, UV and high temperature), that can increase the intracellular oxidation and free radicals as well. Oxidation and free radicals is paved by the animal defensive mechanisms, including accumulation of antioxidant compounds and enzymes. In this study, carpet anemones sampled from intertidal zone of the eastern city of Hormoz Island (IRAN). Extraction was performed by using of PBS and methanol 40% solvents: 2 g dry weight of the mucous, by 2 replications, and 10 g wet weight of the oral plate, by 6 replications, from 6 samples. Different concentrations of extracts were made for antioxidant tests. The antioxidant properties of extract were measured by DPPH and FRC methods. Results showed that a correlation is between the antioxidant activity and the concentration of extracts in two methods. In DPPH assay, IC50 values was 1.469±0.208, 1.85±0.016 for mucus extract by PBS and methanol 40%, respectively, and it was 0.733±0.06, 0.444±0.036 mg/ml, for oral plate extract by PBS and methanol 40%. Our results showed that the antioxidant activity of oral plate was significantly higher than mucous in this anemone.

In this study, a Bacillus species was identified from the Dosarri mineral spring in Jiroft microflora. This strain produce clear halo in casein agar media. It has been identified as Bacillus Pumilus (KHB3) based on biochemical tests and 16S rRNA gene sequencing. To enzyme production, this strain was cultured in specific medium for 48 h. Supernatant was partially purified after precipitation with ammonium sulphate (85 %), dialysis and ion exchange chromatography (Q-Sepharose). KHB3 protease was characterized in the presence of different pHs, ions and detergents. Results indicated that the enzyme showed maximum activity and stability in pH 8.0. This enzyme retained about 100 % of its activity in the presence of 1.0 and 1.5 M NaCl. KHB3 protease showed 33 and 10 % increase in protease activity in the presence of MnSO4 and FeSO4. KHB3 protease retained at least 45 % of its activity and stability in the presence of commercial detergents. In addition, it show 12 % increase in enzyme activity in the presence of Banoo detergent. Activity and stability in alkaline pH, organic solvents and detergent compounds show that this protease has high value capacity in detergent industry.

Plant growth promoting bacteria produce ACC deaminase (EC4.1.99.4) which regulates the biosynthesis of ethylene through cleavage of ACC (immediate precursor of Ethylene) into-ketobutyarate and ammonia. Therefore, it has an important role in plant growth promotion via lowering indigenous ethylene levels especially when the plants are exposed to an environmental stress. Therefore, this study aimed to investigate the cloning, expression, purification and determination of biochemical properties of ACC deaminase from Pseudomonas fluorescense. In this regard, the ACC deaminase encoding gene of Pseudomonas fluoresense FY32 was isolated and cloned in pET28 a (+) and the resultant pET28/acdS construct then was transformed into E. coli BL21(DE3). The expressed enzyme was purified by metal-affinity chromatography on Ni(2+)-TED-Sepharose column and then the optimum conditions and biochemical properties of the purified enzyme was examined. This enzyme showed the highest activity at 28 °C, pH 7 in the presence of 30 mM MgSO4. Also, the significant reduction of ACC deaminase activity was observed in 160 ppm of NaCl. The Km and Vmax of enzyme were calculated to be 9.66 mM and 0.11 nM mg-1 h-1, respectively (determined by the concentration of the produced α-ketobutyrate), which were relatively higher than those previously reported.

Magnetotactic bacteria can be affected by Earth's magnetic field orientation. They have been observed various forms of cocci, bacilli and spirilla. These bacteria make magnetosomes affected by the magnetic field and its orientation as part of the iron is stored. In this study, the presence of magnetotactic bacteria in different parts of Iran with features freshwater pearls saline containing iron mine in Zanjan, Persian Gulf, Mighan and Qom wetlands was investigated. Sediments and water collected were put under magnetic field. Results showed that all types of isolated bacteria were, Gram-negative and shapes to bacillus, spirillum and coccus. The magnetic field in the capillary tube containing a magnetotactic bacterium that responds was observed to magnetic field. Mighan and Qom wetlands and Zanjan's iron mine samples have more cases of magnetotactic bacteria,were studied in particular. Transmission electron microscopy images of iron nanoparticles were visible within it. Results molecular analysis, sequencing and BLAST in NCBI website showed in sample Znjan's iron mine there is Magnetospirillum magnetotacticum strain. Higher concentrations indicate of iron nanoparticles in the sample compared to the Mighan wetland with iron mine, that the abundance of iron ions alone did not increase the level of magnetic nanoparticles of Fe by bacteria.