Yazar "Gul-Guven, Reyhan" seçeneğine göre listele

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    Anoxybacillus kamchatkensis subsp asaccharedens subsp nov., a thermophilic bacterium isolated from a hot spring in Batman
    (Microbiol Res Foundation, 2008) Gul-Guven, Reyhan; Guven, Kemal; Poli, Annarita; Nicolaus, Barbara
    A new thermophilic spore-forming strain KG8(T) Was isolated from the mud of Taslidere hot spring in Batman. Strain KG8(T) was aerobe, Gram-positive, rod-shaped, motile, occurring in pairs or filamentous. Growth was observed from 35-65 degrees C (optimum 55 degrees C) and at pH 5.5-9.5 (optimum pH 7.5). It was capable of utilizing starch, growth was observed until 3% NaCl (w/v) and it was positive for nitrate reduction. On the basis of 16S rRNA gene sequence similarity, strain KG8(T) was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain KG8(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain KG8(T). Based on these results we propose assigning a novel subspecies of Anoxybacillus kamchatkensis, to be named Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov. with the type strain KG8(T) (DSM 18475(T)=CIP 109280(T)).
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    Anoxybacillus sp AH1, an ?-amylase-producing thermophilic bacterium isolated from Dargecit hot spring
    (Springer, 2015) Acer, Omer; Pirinccioglu, Hemse; Bekler, Fatma Matpan; Gul-Guven, Reyhan; Guven, Kemal
    The present study was conducted to isolate alpha-amylase-producing thermophilic bacteria from Dargecit hot springs in Turkey. The morphological, biochemical and physiological characterisation, as well as genetic analysis by 16S rRNA sequences indicated that the isolated strain AH1 was a member of Anoxybacillus genus. The strain was aerobe, Gram-positive and spore-forming rod, exhibiting optimum growth temperature and pH of 60 degrees C and 7.0-7.5, respectively. Optimization of growth medium and enzyme assay conditions for extracellular a-amylase production by the novel thermophilic Anoxybacillus sp. AH1 were carried out in many different media containing a variety of carbon and nitrogen sources. Among various carbon and nitrogen sources, peptone (2054.1 U/mL) at 1% and maltose (1862.9 U/mL) at 0.5% increased a-amylase activity, compared to controls. Moreover, a high enzyme production was observed with potato starch at 0.5% and 1% (2668.4 U/mL and 3627 U/mL, respectively), as well as with 1% soluble starch (2051.9 U/mL). The enzyme activity was found to be rather high in the presence of CaCl2 up to 100 mM.
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    Biosorption of Cd+2, Cu+2, and Ni+2 Ions by a Thermophilic Haloalkalitolerant Bacterial Strain (KG9) Immobilized on Amberlite XAD-4
    (Hard, 2015) Alkan, Huseyin; Gul-Guven, Reyhan; Guven, Kemal; Erdogan, Salt; Dogru, Mehmet
    A newly isolated thermophilic haloalkalitolerant bacterial strain (KG9) as immobilized cells on a solid support was presented as a new biosorbent for the enrichment of Cd(II), Cu(II), and Ni(II) prior to flame atomic absorption spectrometric analysis. The KG9 strain was identified as a close member of Bacillus licheniformis following complete sequencing of 16S rRNA. The optimum conditions such as pH, amount of adsorbent, eluent type and volume, flow rate of sample solution, volume of sample solution, and matrix interference effect on the retention of the metal ions were evaluated for the quantitative recovery of the analytes. The analyte ions were quantitatively recovered and desorbed at pH range of 6.0-7.0 and 5 mL of 0.5 mol.L-1 HCl. The loading capacities of adsorbents for Cd(II), Cu(II), and Nip were found to be 22.7, 61.1, and 33.4 mu mol.g(-1) respectively. The analytical detection limits for cadmium(II), copper(II), and nickel(II) were 0.42 mu g.L-1, 0.54 mu g.L-1, and 1.24 mu g.L-1. The proposed procedure was applied for the determination of metal ions in river water, drinking water, and mushrooms. The accuracy of the developed procedure was tested by analyzing NRCC-SLRS4 riverine water and SRM1570a spinach leaves as the certified reference materials.
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    Extremely low-frequency magnetic field induces manganese accumulation in brain, kidney and liver of rats
    (Sage Publications Inc, 2015) Celik, Mustafa Salih; Guven, Kemal; Akpolat, Veysi; Akdag, Mehmet Zulkuf; Naziroglu, Mustafa; Gul-Guven, Reyhan; Celik, M. Yusuf
    The aim of the present study was to determine the effects of extremely low-frequency magnetic field (ELF-MF) on accumulation of manganese (Mn) in the kidney, liver and brain of rats. A total of 40 rats were randomly divided into eight groups. Four control groups received 0, 3.75, 15 and 60 mg Mn per kg body weight orally every 2 days for 45 days, respectively. The remaining four groups received same concentrations of Mn and were also exposed to ELF-MF (1.5 mT; 50 Hz) for 4 h for 5 days a week during 45 days. Following the last exposure, kidney, liver and brain were taken from all rats and they were analyzed for Mn accumulation levels using an inductively coupled plasma-optical emission spectrometer. In result of the current study, we observed that Mn levels in brain, kidney and liver were higher in Mn groups than in control groups. Mn levels in brain, kidney and liver were also higher in Mn plus ELF-MF groups than in Mn groups. In conclusion, result of the current study showed that the ELF-MF induced manganese accumulation in kidney, liver and brain of rats.
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    Geobacillus galactosidasius sp nov., a new thermophilic galactosidase-producing bacterium isolated from compost
    (Elsevier Gmbh, 2011) Poli, Annarita; Laezza, Giusi; Gul-Guven, Reyhan; Orlando, Pierangelo; Nicolaus, Barbara
    Two thermophilic spore-forming strains, with optimum growth temperature at 70 degrees C, were isolated from compost of the Experimental System of Composting (Teora, Avellino, Italy). A phylogenetic analysis based on 16S rRNA gene sequences showed that these organisms represented a new species of the genus Geobacillus. Based on polyphasic taxonomic data the strains represented a novel species for which the name Geobacillus galactosidasius sp. nov. is proposed. The type strain is CF1B(T) (=ATCC BAA-1450(T) = DSM 18751(T)). (C) 2011 Elsevier GmbH. All rights reserved.
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    Isolation and characterization of long-chain alkane-degrading Acinetobacter sp BT1A from oil-contaminated soil in Diyarbakir, in the Southeast of Turkey
    (Taylor & Francis Inc, 2016) Acer, Omer; Guven, Kemal; Bekler, Fatma Matpan; Gul-Guven, Reyhan
    A strain of long-chain alkane-degrading bacteria, BT1A, was isolated from oil-contaminated soil in Diyarbakr, in the southeast of Turkey. Morphological, biochemical, and physiological characterization and 16S rRNA gene sequence analysis showed that the strain BT1A was a member of Acinetobacter genus, and it was found to be closely related to Acinetobacter baumannii. The strain BT1A was able to utilize crude petroleum as carbon and energy sources in order to grow. Among the aliphatic hydrocarbons, growth was observed only in the medium containing long-chain alkanes (tridecane, pentadecane, and hexadecane) and squalene. Hexadecane was the most preferred hydrocarbon among the long-chain alkanes. Gas chromatography-mass spectrometry (GC-MS) analysis showed that BT1A degraded 83% of n-alkanes of 1% crude oil in 7days. The present study indicates that the isolated strain can well be used for biodegradation of hydrocarbons in oil-contaminated sites.
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    Isolation and characterization of long-chain alkane-degrading Acinetobacter sp. BT1A from oil-contaminated soil in Diyarbakir, in the Southeast of Turkey (vol 20, pg 80, 2016)
    (Taylor & Francis Inc, 2017) Acer, Omer; Guven, Kemal; Bekler, Fatma Matpan; Gul-Guven, Reyhan
    [Abstract Not Available]
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    Preconcentration of cadmium and nickel using the bioadsorbent Geobacillus thermoleovorans subsp stromboliensis immobilized on Amberlite XAD-4
    (Springer Wien, 2010) Ozdemir, Sadin; Gul-Guven, Reyhan; Kilinc, Ersin; Dogru, Mehmet; Erdogan, Sait
    Cadmium and nickel ions have been preconcentrated on Geobacillus thermoleovorans subsp. stromboliensis, immobilized on Amberlite XAD-4, and were determined by flame atomic absorption spectrometry (FAAS). Parameters such as pH, amount of adsorbent, eluent type and volume, flow rate of solution and the matrix interference effect on retention have been studied, and extraction conditions were optimized. Elution of Cd(II) and Ni(II) from minicolumns was carried out with 1.0 M hydrochloric acid or nitric acid with recoveries from 97 to 100%. The sorption capacity is 0.0373 and 0.0557 mmol g(-1) for Cd(II) and Ni(II), respectively. The detection limits were 0.24 mu g L-1 for cadmium and 0.3 mu g L-1 for nickel. The relative standard deviations of the procedure were below 10%. The procedure was validated by analyzing certified reference materials and applied to the determination of Cd(II) and Ni(II) in natural water and food samples.
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    Purification and some properties of a ?-galactosidase from the thermoacidophilic Alicyclobacillus acidocaldarius subsp rittmannii isolated from Antarctica
    (Elsevier Science Inc, 2007) Gul-Guven, Reyhan; Guven, Kemal; Poli, Annarita; Nicolaus, Barbara
    An intracellular beta-galactosidase from a thermoacidophilic A licyclobacillus acidocaldarius subsp. rittmannii was purified by procedures including precipitation with ammonium sulphate, gel permeation, ion-exchange and affinity chromatography and finally by preparative electrophoresis and some properties of the purified enzyme were determined. The homogenous enzyme had a specific activity of 113 U/mg protein, with a fold purification of 163 and a yield of 8%. The Km and kcat values for ONPG were determined as 8.9 mM and 1074 min(-1), respectively in the purified beta-galactosidase from A. acidocaldarius subspecies rittmannii. The bacteria produce thermostable P-galactosidase (EC 3.2.1.23) activity, which exhibits its optimum at the neutral pH region. The pH and temperature optima for the purified enzyme are 6.0 and 65 degrees C, respectively (10 min assay). beta-Galactosidase specific activities of crude extracts obtained from bacterial cells grown in the presence and absence of lactose over a period of time (6-40 h) showed that beta-galactosidase synthesis seems to be constitutive and increases by increasing time up to 40 h of cultivation. beta-Galactosidase activity in the bacteria growing on the medium without lactose was 0.4 U/mg protein and increased up to 0.6 U/mg protein in the cells growing on the medium with lactose at 24 h (an increase by about 33% of its constitutive value), while it was 0.072 and 0.48 U/mg protein, respectively at 12 h (an increase by about 85% of its constitutive value). IPTG was also found to increase beta-galactosidase activity over a short period of time. The molecular mass of the purified enzyme determined by gel filtration on FPLC and SDS-PAGE was 165 and 76 kDa, respectively. The beta-galactosidase from Alicyclobacillus acidocaldarius subsp. rittmannii is most likely to belong to the glycoside hydrolyse family 42. (C) 2006 Elsevier Inc. All rights reserved.
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    The use of Bacillus subtilis immobilized on Amberlite XAD-4 as a new biosorbent in trace metal determination
    (Elsevier Science Bv, 2007) Dogru, Mehmet; Gul-Guven, Reyhan; Erdogan, Sait
    The present work proposes the use of Bacillus subtilis immobilized on Amberlite XAD-4 as new biosorbent in trace metal determination. The procedure is based on the biosorption of Cu and Cd ions on a column of Amberlite XAD-4 resin loaded with dried, dead bacterial components prior to their determination by flame AAS. Various parameters such as pH, amount of adsorbent, eluent type and volume, flow rate of solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH values of quantitative sorption for Cu and Cd were found to be 7.0 and 7.5, respectively. These metal ions can be desorbed with 1 M HCl (recovery, 96-100%). The,sorption capacity of the resin was 0.0297 and 0.035 mmol g(-1) for Cu(2+) and Cd(2+), respectively. The tolerance limit of some electrolytes were also studied. This procedure was applied to Cu(2+) and Cd(2+) determination in aqueous solutions, including river and well water systems. In order to evaluate the accuracy of the proposed procedure, the certified reference materials, NRCC-SLRS-4 Riverine water and LGC7162 Strawberry leaves were analyzed. (C) 2007 Elsevier B.V. All rights reserved.