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Öğe Antimicrobial and antioxidant activities of the various extracts of Verbascum pinetorum Boiss. O. Kuntze (Scrophulariaceae)(Verduci Publisher, 2011) Ozcan, B.; Esen, M.; Caliskan, M.; Mothana, R. A.; Cihan, A. C.; Yolcu, H.Background and Objectives: The present study was performed to evaluate the in vitro antimicrobial and antioxidant properties of various extracts of Verbascum (V.) pinetorum, a member of Scrophulariaceae family. While the antimicrobial activity of various extracts of V. pinetorum was determined with agar-well diffusion method, the antioxidant activity was examined with two complementary test systems, namely 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and beta-carotene/linoleic acid test systems. Results: The hexane extract exhibits antimicrobial activity against few microorganisms. However, dichloromethane, direct methanol and methanol/chloroform extracts are effective on a broad range of microorganisms. Among the tested bacteria Haemophilus influenzae was found to be the most sensitive bacterium. The 50% (IC50) inhibition activity of the methanolic extract of V. pinetorum on the free radical DPPH was determined as 13.04 mg/ml. In the case of the linoleic acid system, oxidation of linoleic acid was inhibited by methanolic extract of V. pinetorum, which showed 89.39% inhibition that is quite close to the value of the synthetic antioxidant reagent butylhydroxytoluene (BHT), 92.46%. Iridoid glycosides, flavonoids and saponins were determined as the major natural compounds in the methanolic extracts. The total phenolic components of V. pinetorum were found as 42.45 mg/g gallic acid equivalent. Conclusion: The results provide evidence that the extracts of V. pinetorum contained iridoid glycosides, flavonoids, saponins and phenolic compounds which may be responsible for the substantial antimicrobial and antioxidant activities.Öğe Characterization of extremely halophilic Archaea isolated from saline environment in different parts of Turkey(Maik Nauka/Interperiodica/Springer, 2006) Ozcan, B.; Cokmus, C.; Coleri, A.; Caliskan, M.Ninety-five extremely halophilic strains were isolated from six distinct saline regions of Turkey by using complex medium containing 25% NaCl. The selected regions are Tuz Golu (salt lake), Ankara; Aci Lake, Denizli; Salda Lake, Denizli; Seyfe Lake, Kyrsherhir; Tuzla Lake, Kayseri; and Bolluk Lake, Konya. The isolated strains were tested for motility, gram reaction, cell and colony morphologies, pigmentation, biochemical characteristics, and antibiotic sensitivities. According to membrane glycerol diether moieties and antibiotic susceptibilities, all isolated strains were found to belong to the domain Archaea. All isolates were examined for the presence of plasmids by agarose gel electrophoresis and it was established that most isolates contained plasmids that varied in number and whose molecular sizes ranged from 1 to 36.9 kbp. Whole-cell protein profiles from isolates were analyzed by SDS-PAGE and a similarity dendogram was constructed using the UPGMA method. Significant similarities and differences were observed among the isolates. The strains were clustered in eight groups and ten of our isolates were placed in the same group with the standard strains. The current study represents the first isolation and characterization of such a large collection of archeal strains from Turkey.Öğe Phylogenetic Analysis and Characterization of Lipolytic Activity of Halophilic Archaeal Isolates(Maik Nauka/Interperiodica/Springer, 2012) Ozcan, B.; Ozyilmaz, G.; Cihan, A.; Cokmus, C.; Caliskan, M.Five isolates designated as B45, D83A, A206A, A85 and E49 found to possess lipolytic activities were taxonomically classified on the basis of their phylogenetic, phenotypic and chemotaxonomic characteristics. The isolates were determined to be gram-negative, catalase and oxidase positive, hydrolyzing Tween 80 and 60 but not starch, need 3.5-4 M NaCl for optimal growth and lack of anaerobic growth with arginine or DMSO. All isolates had the highest lipolytic activity at pH 8.5. Lipase and esterase activities increased with salt concentration up to 3-4.5 M NaCl, and decreased at 5 M NaCl. Esterase and lipase showed their maximal activities at 50-55 degrees C and 60-65 degrees C, respectively. The phylogenetic tree constructed by the neighbor-joining method indicated that the strain B45 and A85 were closely related to the members of genera Halovivax and Natrinema, respectively. The closest relative of the strain A206A and D83A were found to be Haloterrigena saccharevitans. The strain E49 displayed a more distant relationship to known strains.Öğe Phylogenetic analysis and characterization of lipolytic activity of halophilic archaeal isolates.(2012) Ozcan, B.; Ozyilmaz, G.; Cihan, A.; Cokmus, C.; Caliskan, M.Five isolates designated as B45, D83A, A206A, A85 and E49 and found to possess a activity were taxonomically classified on the basis of their phylogenetic, phenotypic and chemotaxonomic characteristics. The isolates were determined to be Gram-negative, catalase and oxidase positive, hydrolyzing Tween 80 and 60 but not starch, need 3.5-4 M NaCl for optimal growth and lack of anaerobic growth with arginine or DMSO. All isolates had the highest lipolytic activity at pH 8.5. Lipase and esterase activities increased with salt concentration up to 3-4.5 M NaCl, and decreased at 5 M NaCl. Esterase and lipase showed their maximal activities at 50-55 degrees C and 60-65 degrees C, respectively. The phylogenetic tree constructed by the neighbor-joining method indicated that the strain B45 and A85 were closely related to the members of genera Halovivax and Natrinema, respectively. The closest relative of the strain A206A and D83A were found to be Haloterrigena saccharevitans. The strain E49 displayed a more distant relationship to known strains.Öğe Salt stress causes a shift in the localization pattern of germin gene expression(Funpec-Editora, 2009) Caliskan, M.The response of plants to biotic and abiotic stress factors involves biochemical, physiological, morphological, and developmental changes. Salt stress has been the subject of extensive studies due to the low salt tolerance of many crop plants. Germin and germin-like gene products are known to be involved in various aspects of plant development, such as defense, embryonic development and response to biotic as well as abiotic stress, including salt. The responses of germin and germin-like genes to salt stress vary in different plants. RT-PCR and in situ RNA hybridization methods were employed to analyze quantitative changes and to detect the localization pattern of germin gene products in salt-stressed and water-grown wheat embryos. Salt stress caused no quantitative changes in the synthesis of germin gene products. However, in situ RNA hybridization revealed changes in the expression site of germin gene products. Coleorhiza cells were found to be the site of germin accumulation in water-grown embryos; however, in salt-stressed embryos, germin mRNA accumulated in coleoptile cells instead of coleorhiza tissue.
