Yazar "Belduz, Ali Osman" seçeneğine göre listele

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    Biochemical characterization of wild-type and mutant (Q9F and S21Y/V22D) iron oxidases isolated from Acidithiobacillus ferrooxidans M1
    (TUBITAK Scientific & Technical Research Council Turkey, 2016) Çolak, Dilsat Nigar; Güler, Halil İbrahim; Çanakçı, Sabriye; Belduz, Ali Osman
    Iron oxidase, a member of the high potential iron-sulfur protein (HiPIP) family within the iron-sulfur cluster, was thought to be involved in the iron respiratory electron transport chain in Acidithiobacillus ferrooxidans. A. ferrooxidans M1 strain was isolated from Murgul copper mine. The iro gene of this bacterium encoding iron oxidase was cloned, and the complete nucleotide sequence was disclosed. The gene was cloned and overexpressed successfully. The highly conserved amino acid residues within the iron oxidase enzyme sequence were determined, and their Q9F and S21Y/V22D recombinants were created through site-directed mutagenesis. Wild-type and recombinant iron oxidase enzymes were purified and further characterized. The biochemical properties and kinetic parameters of wild-type and mutant enzymes were determined and compared. The optimal temperature of the wild-type enzyme was 25 degrees C, and maximal activity was observed at pH 4.0. The Km and Vmax values of wild-type enzyme were 0.27 +/- 0.09 mM and 0.083 +/- 0.01 mu mol/min/mg protein, respectively. Although the mutant enzymes were almost comparable to wild-type enzyme, their maximal activities moved from pH 4.0 to pH 3.5, and pH stability of S21Y/V22D mutant was improved compared to wild type.
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    Brevibacillus gelatini sp nov., isolated from a hot spring
    (Microbiology Society, 2016) İnan, Kadriye; Özer, Ayşegül; Belduz, Ali Osman; Çanakçı, Sabriye; Güler, Halil İbrahim
    Two Gram-stain-positive, moderately thermophilic, endospore-forming, rod-shaped, motile bacteria designated PDF4(T) and PDF10, were isolated from Camkoy hot spring in the provinces of Aydin, Turkey and were characterized in order to determine their phylogenetic position. 16S rRNA gene sequence analysis revealed that the two strains belonged to the genus Brevibacillus. Strain PDF4(T) showed highest 16S rRNA gene sequence similarity to strain PDF10 (99.5 %), Brevibacillus brevis DSM 30(T) (98.9 %), Brevibacillus parabrevis DSM 8376(T) (98.6 %) and Brevibacillus formosus DSM 9885(T) (98.5 %); similarities to other species of the genus Brevibacillus were less than 98.5 %. The predominant fatty acids of strain PDF4(T) were anteiso-C-15 : 0 (60.0 %) and iso-C-15 : 0 (22.3 %). The polar lipids of strain PDF4(T) consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, an unknown phospholipid, two unknown lipid, an unknown aminophospholipid and two unknown aminolipids. MK-7 was detected as a sole respiratory quinone, and the cell wall of strain PDF4(T) contained meso-diaminopimelic acid. The DNA G + C content of strain PDF4(T) was 51.7 mol%. DNA-DNA hybridization showed less than 60 % relatedness between strain PDF4(T) and type strains of the most closely related species given above. Based on these data, the two strains are considered to represent a novel species of the genus Brevibacillus, for which the name Brevibacillus gelatini sp. nov. is proposed. The type strain is PDF4T (=NCCB 100559(T) =DSM 100115(T)).
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    Cloning, expression, and characterization of a novel CTP synthase gene from Anoxybacillus gonensis G2
    (TUBITAK Scientific & Technical Research Council Turkey, 2014) Sandallı, Cemal; Saral, Ayşegül; Ülker, Serdar; Karaoğlu, Hakan; Belduz, Ali Osman; Çopur Çiçek, Ayşegül
    The cytidine-5'-triphosphate (CTP) synthase (EC 6.4.3.2) gene (pyrG) was cloned and sequenced from the thermophilic bacterium Anoxybacillus gonensis G2 (Ago). The gene is 1590 bp in length and encodes a protein of 530 amino acids, with a molecular mass of 59.5 kDa. The amino acid sequence of CTP synthase shares approximately 90%-94% similarity to Bacillus sp., and it belongs to the triad glutamine amidotransferases, which utilize a Cys-His-Glu triad for activity. Multiple sequence alignments revealed that the enzyme includes conserved amino acids responsible for catalytic activity and the binding of a divalent metal ion (Mg+2). AgoCTP synthase (AgoG2CTPs) was overproduced in Escherichia coli BL21 (DE3) pLysS as recombinant and purified by nickel affinity chromatography. Its biochemical characterization showed that the enzyme had maximal activity at pH 9.0-10.0 and 65 degrees C. K-m, V-max, and k(cat) were found to be approximately 12.415 mM, 0.381 U/L, and 0.762 s(-1) at 65 degrees C, respectively. CTP synthase promotes the formation of CTP in dividing cells and is a recognized target for anticancer and antibacterial drugs. The results obtained from this study can be improved upon with the use of different species and substrates.
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    Thermus anatoliensis sp nov., a thermophilic bacterium from geothermal waters of Buharkent, Turkey
    (Wiley, 2015) Kaçagan, Murat; İnan, Kadriye; Çanakçı, Sabriye; Güler, Halil İbrahim; Belduz, Ali Osman
    A Gram-stain-negative, lack of motility, catalase- and oxidase- positive bacterium (strain MT1(T)) was isolated from Buharkent hot spring in Aydin, Turkey. Its taxonomy was investigated using a polyphasic approach. The strain was able to grow at 45-80 degrees C, pH 5.5-10.5 and with a NaCI tolerance up to 2.0% (w/v). Strain MT1(T) was able to utilize d-mannitol and l-arabinose, not able to utilize d-cellobiose as sole carbon source. 16S rRNA gene sequence analysis revealed that the strain belonged to the genus Thermus; strain MT1(T) detected low-level similarities of 16S rRNA gene sequences (below 97%) compared with all other species in this genus. The predominant fatty acids of strain MT1(T) were iso-C-15:0 (43.0%) and iso-C-17:0 (27.4%). Polar lipid analysis revealed a major phospholipid, one major glycolipid, one major aminophospholipid, two minor aminolipids, one minor phospholipid, and several minor glycolipids. The major isoprenoid quinone was MK-8. The DNA G+C content of MT1(T) was 69.6 mol%. On the basis of a taxonomic study using a polyphasic approach, strain MT1(T) is considered to represent a novel species of the genus Thermus, for which the name Thermus anatoliensis sp. nov. is proposed. The type strain is MT1(T) (=NCCB 100425(T) =LMG 26880(T)).