BIOLOGICAL SCIENCES (DANISH-I ZISTI-I IRAN)
Year:2008 | Volume:3 | Issue:1|Papers Count:7

The main purpose in this research is, collection and recognition bacteria that use oil as the source of energy and carbon, degrade it to recyclable material, find biosurfactatnt producing bacteria, know their applied potential in oil industry, remove oily contaminated elements and clean the nature soil and water environment. For separating bacteria from contaminated soil and water, was cultured with serial dilution method in Plate Count Agar medium, then the number of bacteria and the rate of isolation was increased by culturing the bacteria in enrichment medium (MS1) that was suitable for oil degrading bacteria, then they was cultured in synthetic medium that contains Agar+1% sterile crude oil as the source of carbon and energy, and 40 strains was selected. Then blood agar medium was used for haemolytic activity and MSS+1%Yeast Extract medium for measurement of surface tension, as the point of early separating and separating biosurfactant producing bacteria, respectively. 12 different strains was collected with beta haemolitic activities, at last 3 strains that could reduce surface tension less than 40 mN/m was chosen. By using additional tests such as, toxicity test of crude oil by using of MS2 medium, measurement of growth and produce biosurfactant in different salt concentration, biosurfactant producing from non-oily sources and measuring emulsifying activity in Cooper medium, one strain was selected, as the best biosurfactant producing strain that has highest results in experiments. Selected strain was a Gram-negative Coccobacillus that can produce biosurfactant in wide range of pH (2-14), and using glucose and paraffin as the source of carbon and reduce surface tension less than 40 mN/m. Produced biosurfactant was recognized as glycolipids in nature that was stable during exposure to high salinity (up to10% NaCl) and elevated temperatures (100-120oC for 15 minutes) by TLC method. At last by 16S rRNA sequencing, the real bacterial genus and strain was recognized as: Pseudomonas aeruginosa.

In order to study on effect Azospirillum on sunflower cultivar seeds that produced under low water stress, an experiment was conducted in form of factorial completely randomized design with three replications. Treatments are include water stress [Irrigation plants after 60 (Normal irrigation), 120 (Mild stress), 180 (Severe stress) mm evaporate from pan class A, with five Cultivar and Seed inoculation [Inoculation with Azospirillum, No inoculation]. Results showed that water stress decreased abnormal seedling, rust seed, vigor and seedling weight. Azospirillum increased root, stem and seedling length respectively 5, 20 and 11 percent and root, stem, seedling fresh weight respectively 25, 18, 19 percent than no inoculation. Seeds produced under water stress had 13 percent higher than normal irrigation. Increased 4 percent seed viability of seeds produced under severe stress. Seeds produced under water stress had lower rust seed amount and Azospirillum decreased than no inoculation. With attention to negative effect of water stress, Azospirillum increased seed viability, length, weight and vigor seedling.

Horsetail genus (Equisetum L.) belongs to Equisetaceae. There are 25 living species in the world that are identified and these species are distributed worldwide, except Australia and New Zealand.5 species are reported from Iran which are: E. telmateia Ehrh., Hannov. Mag., E. ramosissimum Desf., E. arvense L., E. fluviatile L. and E. palustre L.3 new records have been reported from the north of Iran for the first time for Iranian sphenoflora: E. variegatum Schleicher ex Weber & Mohr., E. pratense Ehrh. and E. hyemale L. Plants specimen were collected from humid and semi-humid regions of Golestan, Guilan, Mazandaran, Ardabil, Qazvin & Tehran province. For identifying every record, morphological characters such as stem length, the number of sheets, the number of grooves, were used.

The Purpose of this study was to determine norm frame of VO2 max for female students of Islamic Azad University at Varamin branch. Accordingly, 500 female students with the height mean equal to 160±2.4 cm and weight mean equal to 58±3.7 kg were selected from different field studies. Then, measurement of height and weight were done and physical activity rates (PA-R) were determined. Afterward, measurements of VO2 max and body fat percentage were estimated by related equations for every subject. After this stage, the norm of VO2 max, was framed. On the whole, the analysis of data with taking advantage of software presents that: VO2 max mean of female students of Islamic Azad University at Varamin branch is 35.24 ml.kg-1. min-1. On the whole, this study shows that aerobic fitness of female students of Islamic Azad University at Varamin Branch is at an acceptable level.

The Expression level of recombinant proteins in Escherichia coli can be affected by several factors. It has been observed that codon replacement at Translation Initiation Region (TIR), critically changes the heterologous expression in E. coli. This study aims to evaluate the effect of replacing rare codons with optimal codons in TIR on the expression level of human basic Fibriblast Growth Factor (hbFGF) in E.coli. For this purpose a long primer with 5 altered codons for the relative amino acid were designed to construct the TIR in a different way. The altered gene was then cloned in an expression vector and new construct was transformed into 3 different strains of E.coli. The induction of protein expression in these strains exhibited a significant change in expression levels which reemphasized the role of TIR codons in the efficiency of protein expression in E.coli. In conclusion the results suggest that nucleotide sequence in TIR has a key role in the level of hbFGF expression in E. coli.

Urinary tract infections (UTIs) are a significant cause of morbidity in people of all ages. Sexually active young women, elderly people and those undergoing catheterization or genitourinary instrumentation are at risk. Enterobacter species are rod-shaped bacteria which belong to family Enterobacteriaceae. They are found in the environment and in the human intestinal tract. Some species (E. cloacae and E. aerogenes) are the most pathogenic species which can cause opportunistic infections in immunocompromised patients. The urinary and respiratory tracts are the most common sites of infection with Enterobacter species, but bloodstream infection may occur on occasion. Aminoglycosides and fluoroquinolone are two groups of practical broad-spectrum antibiotics in UTIs treatment. Fluoroquinolones interfere with the enzyme DNA gyrase which is needed for synthesis of bacterial DNA, and aminoglycosides work by binding to the bacterial 30S ribosomal subunit (some work by binding to the 50S subunit). They kill bacteria by inhibiting protein synthesis as they bind to the 16S rRNA and by disrupting the integrity of bacterial cell membrane. Susceptibility of clinical isolates of Enterobacter species (40 isolates from laboratories specimens in Tehran) to aminoglycosides (gentamicin and amikacin) and to fluoroquinolones (ciprofloxacin and ofloxacin) was determined by two methods: Disk Diffusion susceptibility and broth dilution. Results of two methods agreed with each other most of the time. There was variable range of MIC for each groups of antibiotic against Enterobacter species. Results of MIC as measured in broth and Disk Diffusion were generally comparable, it means every antimicrobial agent which produced a greater zone diameter had less MIC amount. At concentration of 128mg/ml, all antibiotics inhibited 100% of strains. Average of inhibitory concentrations of four antibiotics for all strains were: ciprofloxacin 0.925 mg/ml, ofloxacin 4.1626 mg/ml, gentamicin 7.5781mg/ml and amikacin 7.5375 mg/ml. The numbers of resistant strains to ciprofloxacin were less than the others. The MBC amounts for 4 groups of antibiotics are at most 16-fold more than MIC. In general, resistant strains to four groups of antibiotics were insufficient. The surveys indicated that they are still promising antibacterial agents for treatment of Enterobacter strains.

Urolithiasis is a worldwide problem, sparing no geographical, cultural, or racial groups. Kidney stones are composed of inorganic and organic crystals amalgamated with proteins. Crystallisation and subsequent lithogenesis can happen with many solutes in the urine. Calcareous stones are still by far the most common nephroliths accounting for more than 80% of stones. In Iranian folk medicine, many plants are used for treatment of kidney stones. In the present study, effect of ethanolic extract of Zea mays tuft on calcium oxalate crystallization in vitro was studied. At first, ethanolic extract of plant at doses of 0.25, 0.5, 1, 2 and 4 mg/ml were prepared. Calcium oxalate crystallization was induced by adding sodium oxalate to urine samples of 6 men. Calcium oxalate crystallization in absence or presence of plant extract was compared. The present results showed that the plant increased number of crystals in comparison to control samples. On the other hand, the plants increased small crystals, while decreased big crystals in experimental samples. Also, the plant increased mono-hydrate calcium oxalate crystals in comparison to di-hydrate calcium oxalate crystals. So, Zea mays is a good candidate for prevention of calcium oxalate crystallization.