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Öğe Antimicrobial and Antioxidant Activities of Various Extracts of Verbascum antiochium Boiss. (Scrophulariaceae)(Mary Ann Liebert, Inc, 2010) Ozcan, Birgul; Yilmaz, Miray; Caliskan, MahmutVerbascum antiochium Boiss., a member of the Scrophulariaceae family, is endemic to Turkey. The extracts obtained from V. antiochium by increased polarity and direct methanol extraction were tested by the agar well diffusion method against various Gram-positive and Gram-negative bacteria and one fungus. The methanol/water extract exhibited a larger inhibition zone against both the Gram-negative and Gram-positive bacteria than the other extracts. Haemophilus influenzae was found to be the most sensitive bacterium among the bacteria tested. The antioxidant activities of the methanolic extract of V. antiochium were examined by two complementary test systems. The 50% inhibition activity of the methanolic extract of V. antiochium against the free radical 2,2-diphenyl-1-picrylhydrazyl was determined as 4.80 mg/mL. In the case of the linoleic acid system, oxidation of linoleic acid was inhibited by the methanolic extract of V. antiochium with 79.92% inhibition, which is close to the value of the synthetic antioxidant reagent, tert-butylated hydroxytoluene. The total phenolic components of V. antiochium were determined to be 92.71 mg of gallic acid equivalents/g. Iridoid glycosides, flavonoids, and saponins were detected as the major chemical constituents in the extract.Öğe Characterization of extracellular esterase and lipase activities from five halophilic archaeal strains(Springer Heidelberg, 2009) Ozcan, Birgul; Ozyilmaz, Gul; Cokmus, Cumhur; Caliskan, MahmutA total of 118 halophilic archaeal collection of strains were screened for lipolytic activity and 18 of them were found positive on Rhodamine agar plates. The selected five isolates were further characterized to determine their optimum esterase and lipase activities at various ranges of salt, temperature and pH. The esterase and lipase activities were determined by the hydrolysis of pNPB and pNPP, respectively. The maximum hydrolytic activities were found in the supernatants of the isolates grown at complex medium with 25% NaCl and 1% gum Arabic. The highest esterase activity was obtained at pH 8-8.5, temperature 60-65A degrees C and NaCl 3-4.5 M. The same parameters for the highest lipase activities were found to be pH 8, temperature 45-65A degrees C and NaCl 3.5-4 M. These results indicate the presence of salt-dependent and temperature-tolerant lipolytic enzymes from halophilic archaeal strains. Kinetic parameters were determined according to Lineweaver-Burk plot. The KM and V (max) values were lower for pNPP hydrolysis than those for pNPB hydrolysis. The results point that the isolates have higher esterase activity comparing to lipase activity.Öğe Comparison of chemical composition of the essential oil of Laurus nobilis L. leaves and fruits from different regions of Hatay, Turkey(Triveni Enterprises, 2007) Sangun, Mustafa Kemal; Aydin, Ebru; Timur, Mahir; Karadeniz, Hatice; Caliskan, Mahmut; Ozkan, AydinThe essential oils of the leaves and fruits from bay (Laurus nobilis L.) grown in Antakya, Yayladagi and Samandagi were isolated by solvent extraction and analysed by capillary gas chromatography (GC), gas chromatography and mass spectrometry (GC/MS). In Antakya, Yayladagi and Samandagi the chemical compositions of the fruits and leaves were similar according to qualitative and quantitative analysis. Although in both fruits and leaves the major component was found to be 1.8-Cineole a concentration of about 50% compared with essential oils. The composition of the essential oil from the leaves has high content of 1.8-Cineole, Sabinene and alpha-Terpinyl acetate, but a low content of alpha-Pinene, alpha-Phellandrene and trans-beta-osimen. 1.8-Cineole was found major component of the leaves essential oil collected from Samandagi (59.94%) which is sea coast of region. Interestingly alpha-Pinene, beta-Pinene, alpha-Phellandrene, 1.8-Cineole and trans-beta-osimen were found the major components of fruits of Laurus nobilis L. harvested from Antakya, Yayladagi and Samandagi. Trans-beta-osimen was detected as the major component of fruits essential oil collected again from Samandagi (28.35%).Öğe Effective antibacterial and antioxidant properties of methanolic extract of Laurus nobilis seed oil(Triveni Enterprises, 2010) Ozcan, Birgul; Esen, Mari; Sangun, M. Kemal; Coleri, Arzu; Caliskan, MahmutThis study was carried out to determine the in vitro antimicrobial and antioxidant activities of the essential oil, seed oil, and methanolic extract of seed oil obtained from Laurus nobilis L. (Lauraceae). The methanolic extract of seed oil exhibited more effective antibacterial activity comparing to essential oil and seed oil. GC-MS analyses of the essential oil resulted in the identification of 25 compounds. 1.8-Cineol (44.72%), a-Terpinyl acetate (12.95%), Sabinene (12.82%) were the main components. The fatty acid composition was characterized with the high content of linoleic acid (40.79%) and lauric acid (38.08%). The 50% (IC50) inhibition activity of the essential oil on the free radical DPPH was determined as 94.655 mgml(-1), whereas IC50 value of methanolic extract of seed oil was found unstable. In the case of the linoleic acid system, oxidation of linoleic acid was inhibited by essential oil and methanolic extract of seed oil, which showed 64.28 and 88.76% inhibition, respectively The inhibition value of the methanolic extract of seed oil was quite close to the synthetic antioxidant BHT, 92.46% inhibition.Öğe Formation of wheat (Triticum aestivum L.) embryogenic callus involves peroxide-generating germin-like oxalate oxidase(2004) Caliskan, Mahmut; Turet, Müge; Cuming, Andrew C.In wheat (Triticum aestivum L.), embryogenic callus formation comprises suppression of precocious germination by the zygotic embryo and the initiation of dedifferentiated cellular proliferation within it. Embryogenic calli are induced by treating immature embryos with 2,4-dichlorophenoxyacetic acid (2,4-D). Upon withdrawal from 2,4-D, somatic embryos develop from the periphery of the callus. Prior to visible callus formation, there is a striking induction of "germin-like" oxalate oxidase ("gl-OXO": EC 1.2.3.4) gene expression. Accumulation of gl-OXO mRNA is rapidly stimulated upon auxin treatment, with a consequent development of apoplastic enzyme activity producing H2O2 within the cell wall. Within the dedifferentiated calli, gl-OXO enzyme activity becomes widespread over the surface of embryogenic calli. Differentiation of somatic embryos is initiated in regions of densely cytoplasmic, meristematic cells that are marked by highly localised expression of gl-OXO activity within these embryogenic cell masses. We suggest that this localised generation of H2O2 by gl-OXO promotes peroxidative cross-linking of cell wall components, thereby preventing cellular expansion and maintaining these cell masses in an embryogenically competent condition. © Springer-Verlag 2004.Öğe GENETIC DIVERSITY IN MICROORGANISMS Preface(Intech Europe, 2012) Caliskan, Mahmut[Abstract Not Available]Öğe Öğe Genetic variation of Atlantic horse mackerel (Trachurus trachurus) in the Turkish waters(Cahiers De Biologie Marine, 2009) Turan, Cemal; Ozturk, Bayram; Caliskan, Mahmut; Duzgunes, Ertug; Gurlek, Mevlut; Yaglioglu, Deniz; Hazar, DurulGeographic variations of Truchurus trachurus based on mitochondrial 16S rDNA gene from 8 locations, including the Black, Marmara, Aegean and north-eastern Mediterranean Seas, were investigated. Restriction fragment length polymorphism (RFLP) analyses revealed 14 different composite haplotypes for 307 individuals and diagnostic restriction sites for discriminating among populations. The distribution of haplotypic groups mostly followed the geographic origin of populations. Average haplotype diversity within populations was high (0.7311), and nucleotide diversity was low (0.0071). Mean nucleotide divergence among samples of T. trachurus was 0.00271. The highest value of pairwise inter-group nucleotide divergence was detected between the West and East Black Sea samples (0.01119), and the lowest (-0.00018) between the two North-eastern Mediterranean samples. In Monte Carlo pairwise comparisons of haplotype frequencies genetically different populations were detected. The distribution of haplotypes and the pairwise estimate of nucleotide divergence exposed high differentiation of the Black Sea (BS2) population with respect to the others. Mantel's test showed that the genetic distances between these Populations were not associated with their geographical distances (r = 0.326; P > 0.05).Öğe In vitro antimicrobial and antioxidant activities of various extracts of salvia microstegia (boiss.) et. bal. from antakya, Turkey(2009) Ozcan, Birgul; Esen, Mari; Coleri, Arzu; Yolcu, Hikmet; Caliskan, MahmutThe present study was performed to evaluate the in vitro antimicrobial and antioxidant properties of various extracts (hexane, dichloromethane, methanol/chloroform, methanol/water and direct methanol) from Salvia microstegia (Boiss.) Et. Bal., a member of Lamiaceae family. Direct methanol extracts of S. microstegia exhibited more effective antibacterial activities on the Gram-negative and Gram-positive bacteria. None of the extracts exhibited any antifungal activities on the Candida albicans ATCC 10231. The total phenolic components of S. microstegia was found 103.64 mg/g gallic acid equivalent. The antioxidant activity of the methanolic extract of S. microstegia was examined with two complementary test systems; 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ß-carotene-linoleic acid assays. The 50% (IC50) inhibition activity of the methanolic extract of S. microstegia on the free radical DPPH was determined as 7.63 mg/ml. In the case of the linoleic acid system, the methanolic extract of S. microstegia showed 79.92% inhibition, this value is quite close to the value of synthetic antioxidant reagent, 92.46%. © by PSP Volume 18-No 5a. 2009.Öğe IN VITRO ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES OF VARIOUS EXTRACTS OF Salvia microstegia (BOISS.) ET. BAL. FROM ANTAKYA, TURKEY(Parlar Scientific Publications (P S P), 2009) Ozcan, Birgul; Esen, Mari; Coleri, Arzu; Yolcu, Hikmet; Caliskan, MahmutThe present study was performed to evaluate the in vitro antimicrobial and antioxidant properties of various extracts (hexane, dichloromethane, methanol/chloroform, methanol/water and direct methanol) from Salvia microstegia (Boiss.) Et. Bal., a member of Lamiaceae family. Direct methanol extracts of S. microstegia exhibited more effective antibacterial activities on the Gram-negative and Gram-positive bacteria. None of the extracts exhibited any antifungal activities on the Candida albicans ATCC 10231. The total phenolic components of S. microstegia was found 103.64 mg/g gallic acid equivalent. The antioxidant activity of the methanolic extract of S. microstegia was examined with two complementary test systems; 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. The 50% (IC50) inhibition activity of the methanolic extract of S. microstegia on the free radical DPPH was determined as 7.63 mg/ml. In the case of the linoleic acid system, the methanolic extract of S. microstegia showed 79.92% inhibition, this value is quite close to the value of synthetic antioxidant reagent, 92.46%.Öğe Isolation, Characterization and Phylogenetic Analysis of Halophilic Archaea from a Salt Mine in Central Anatolia (Turkey)(Polskie Towarzystwo Mikrobiologow-Polish Society Of Microbiologists, 2012) Yildiz, Evrim; Ozcan, Birgul; Caliskan, MahmutThe haloarchaeal diversity of a salt mine, a natural cave in central Anatolia, was investigated using convential microbiological and molecular biology methods. Eight halophilic archaeal isolates selected based on their colony morphology and whole cell protein profiles were taxonomically classified on the basis of their morphological, physiological, biochemical properties, polar lipid and protein profiles and 16S rDNA sequences. From the 16S rDNA sequences comparisons it was established that the isolates CH2, CH3 and CHC resembled Halorubrum saccharovorum by 98.8%, 98.9% and 99.5%, respectively. There was a 99.7% similarity between the isolate CH11 and Halobacterium noricense and 99.2% between the isolate CHA1 and Haloarcula argentinensis. The isolate CH8K and CH8B revealed a similarity rate of 99.8% and 99.3% to Halococcus dombrowskii, respectively. It was concluded that the isolates named CH2, CH3 and CHC were clustered in the genus Halorubrum and that CHA1 and CH7 in the genus Haloarcula, CH8K and CH8B in the genus Halococcus and CH11 in the genus Halobacterium.Öğe A plasma membrane H+ATPase gene is germination-induced in wheat embryos(Academic Journals, 2010) Caliskan, Mahmut; Bashiardes, Stavros; Cuming, Andrew C.The expression pattern of a germination specific plasma membrane H+-ATPase was analyzed by RTPCR and in situ RNA hybridization methods. RT-PCR results revealed that germination specific plasma membrane H+-ATPase accumulation was detectable in all organs and tissues of germinating wheat embryos. H+-ATPase expression was not observed in dry wheat embryos and in immature wheat embryos. In situ RNA hybridization indicated that germination specific plasma membrane H+-ATPase gene expression was associated with all organs of germinating wheat tissues. The accumulation of H+-ATPase mRNA was more heavily on the cells of vascular bundles and epidermal cells of coleoptiles. Since germination specific plasma membrane H+-ATPase gene was identified as a growth related gene, interest was focused on the activity of growth regulators (GA, IAA, ABA) and stress factors, NaCl and Mannitol, on H+-ATPase gene expression. The results indicated that there were not any dramatic changes in the accumulation of germination specific plasma membrane H+-ATPase gene in any case. More rigorous analysis is necessary to evaluate the effect of growth regulators on germination specific plasma membrane H+-ATPase.Öğe The Roles of Germin Gene Products in Plants Under Salt Stress(Intech Europe, 2011) Caliskan, Mahmut[Abstract Not Available]
