نشریه زیست شناسی کاربردی
سال بیست و سوم شماره 2 (پاییز و زمستان 1389)

Skin coloration patterns in fish are of great physiological, behavioral and ecological importance, can be considered as an index of animal welfare in aquaculture and as an important quality factor for the retail value. In the present study the effect of different doses (0, 300, 400 and 1000 mg/kg of diet) of commercial methyltestosterone on three-dimensional characteristics of skin color appearance (lightness — L*, hue — H ◦ab and chroma —C◦ab) with a new index named Entire Color Index (ECI) were investigated. For data analyzing, because of the nature of the color factors, circular distribution was used. The lightness of the caudal fin was significantly (p<0.05) higher than body in all the doses except 1000 mg/kg. The lightness of the body area primarily decreased and then increased in 1000 mg/kg. With increasing the doses, the tendency to the redness Hue was increased. In addition we had significant difference in Hue values between body and caudal fin area. As a result, with increasing the dose of hormone, red pigments, and therefore attractiveness of the male were increased and this differences in color factors could be resulted to the increasing the retail values.

DNA extraction is the first stage of gene structure and function study, and finding an effective protocol for isolation DNA in genetic engineering and microbiology studies is essential. There are many different methods for DNA extraction which are interchangeable depending on the wall and membrane structure in the bacterium. The aim of this study was the assessment of different methods for DNA extraction from gram-negative bacterium (Pseudomonas aeruginosa) and the selection of effective protocol. In this study three different methods of DNA extraction from gram-negative bacterium (Pseudomonas aeruginosa) is compared to determine the quantity and the quality of the DNA. These methods include lysis buffer containing proteinase K, DNGTM-plus kit and boiling. In each method, ten samples were selected in a completely random plan and the concentration of DNA was measured using spectrophotometer, Nanodrop and agarose gel electrophoresis. Variance analysis illustrated a meaning difference between three methods. Also average comparison using Duncan test illustrated meaning difference. Finally, boiling method was considered as the most suitable method with the highest extraction efficiency.

22 strain of alkalophilic bacteria isolated from Guilan alkali soils were screened on milk agar medium for their ability to produce alkaline protease. Among isolated bacteria, bacillus spp. was show the highest enzyme production ability. Maximum enzyme production was achieved with sugar 1.5% w/v (as sole carbon source), ammonium sulfate 1% (as sole nitrogen source), pH= 9.5 and 40˚C over a 24 hrs. incubation.

The genus Malva L. with 8 species and 8 varieties in Iran has a wide spread distribution. For studying the cladistic analysis of the species, 18 characters were studied. The characters have entered to the matrix as multistate character. For rooting the shortest tree, we have used three species: Alcea flavovirens, Althaea officinalis, Lavatera thuringiaca as out groups. By using parsimony analysis based on Fitch method the shortest tree with 8.67024 steps has resulted (RI=0.82, CI=0.64). The majority rules consensus tree has selected. The most parsimony cladogram didnt support monophyly of Malva species. The species in our analysis didnt occur in one clade. Also Bootstrap analysis didnt show the monophyly of Malva species.

Hyoscyamus is one of the medicinal plants, rich of tropane alkaloids. In this research the effects of nitrate and ammonium on secondary metabolite and other physiological parameters, were investigated.he results indicated that when nitrate and ammonium both were present in nutrient solution and ammonium concentration was lower than nitrate, dry and fresh weight of root and shoot increase but by increasing ammonium concentration, plant growth decrease. R/S ratio and root and shoot soluble carbohydrate, significantly decrease in plants treated with higher ammonium concentration. Shoot and root chlorophyll content and protein content were increased. Assay of nitrate reductase activity (NRA) showed that in presence of low ammonium concentration, as well as nitrate, NRA increased. By increasing of ammonium concentration, it will be decreased.Alkaloid content was increased in both nitrate and ammonium fed plant, on condition that, ammonium concentration was lower than nitrate.

During the years 2001 – 2002 marine chemical pharmacology research experienced a global phase. In recent years, compounds extracted from marine organisms have shown anti-inflammatory and Anti-Bacterial effects. Pennatulaceas are a particular group of Anthozoa, animals stuck to the bed of water living in all regions of the world usually regions above 6100 meters of tide. To assess inflammation, Gezylin were applied to the ear of mice. Male NMRI mice were categorized into three groups including positive control (dexamethasone15 mg. kg), negative control (saline) and experimental one. The mice of the experimental group were injected with doses of 10 mg/kg, 20 mg/kg and 40 mg/ kg of lipid extract of chloroform and hexane as a separate group within the prescribed characters. Statistical analysis was performed on the results which indicated that anti-inflammatory effect of all doses of 10-40 mg/kg are significant to the control group but there was no significant difference to dexamethasone so that chloroform and hexane extracts of sea pen has a strong anti-inflammatory effects even at low doses which is probably due to 54. 2% arshidonic acid in the compounds. Anti-bacterial and anti fungul effect of hexan and choloroform extract with disk diffusion method, By examition of ِMIC and MBC detering showed choloroform extract has the best activity against Staphylococcus areus on 125µg/ml doze in MIC method and for MBC in same bactery on 250 µg/ml.

Xylan the major portion of the hemicellulose of plant cell wall is a heterogeneous polysaccharide. Xylanases (EC:3.2.1.8) are enzymes obtained from different species of microorganisms that degrade the xylosidic linkages of xylan’s backbone producing xylose plus other monoresidues. In this study xylanase of Bacillus stearothermophilus (ATCC 12980) was purified from culture broth supernatant using ammonium sulfate precipitation, gel filtration on sephadex G-100 followed by ion exchange chromatography on DEAE-cellulose and hydrolysis effect of purified xylanse on two kinds of xylan (birch wood and oat spelts) was studied. In DEAE-cellulose column chromatography, three protein peaks F-1a, F-1b and F-1c were appeared. Among these peaks, only F-1b showed xylanase activity and the degree of purification attained 63.09 fold. The specific activity and purification fold of the purified xylanase was 87.7 U/mg of protein and 17.45, respectively. Hydrolysis of birch wood and oat spelts by purified xylanase was 100% and 56.8% in 24 h, respectively. In conclusion, these data suggested that purified xylanase can be suitable for industrial applications in that birch wood was used.