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    A Comparative study on the activity of oxygenic photosynthetic consortia on marble and granite
    (INT ASSOC COMPUTER SCIENCE & INFORMATION TECHNOLOGY PRESS-IACSIT PRESS, 2011) Karaca, Zeki; Ozturk, Ayten; Unsal, Tuba; Dan, Y
    This Many kinds of microorganisms are playing key role in degradation of historical artifacts, buildings and monuments made of marble, granite and other dimension stones. It is well known that, photoautotrophic microorganisms predispose the stone surface as a breeding-ground for other group of microorganisms. However, the effects of photoautotrophic and other microorganisms on stone materials, where hygiene is crucial, are not well known. Until now, the relation between microorganisms and rock properties and its effect on usage is not investigated. In this study; the biological weathering of AW (true marble) and BP (granite) has been investigated in laboratory condition. Both stone surfaces also supported a heavy colonization of phototrophic microbial consortia (outer and inner part, respectively). After phototrophic microbial growth on AW and BP, while AW turned to yellowish green from original white color, BP turned to green from original grey color. Inner sides of stones, filamentous biota, are possible member of cyanobacteria, were dominant. However, small spherical aggregates, possible calcified globular bodies on the stones were detected with SEM studies.
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    Biodegradation of reactive red 195 azo dye by the bacterium Rhodopseudomonas palustris 51ATA
    (ACADEMIC JOURNALS, 2012) Celik, Leyla; Ozturk, Ayten; Abdullah, Meysun I.
    The sulphonated reactive red 195 dye (RR195) was used as carbon source and energy by the widely spread, eco-friendly, photoheterothrophic strain 51ATA that belongs to Rhodopseudomonas palustris. This bacterium, which was isolated from Lake Akkaya, (Nigde, Turkey), was able to completely degrade and mineralize the dye under anaerobic conditions with 100% efficiency. The degradation efficiency of this strain, in the presence and absence of a co-substrate was investigated. The biodegradation of the dye was monitored by UV-visible, (FTIR) spectroscopy and HPLC. From these analyses, a complete mineralization of the toxic aromatic ring system of the reactive red 195 dye was observed.
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    Biofouling of marbles by oxygenic photosynthetic microorganisms
    (SPRINGER HEIDELBERG, 2015) Karaca, Zeki; Ozturk, Ayten; Colak, Emel
    Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.
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    BIOSORPTION OF DICHLORVOS BY THE ANAEROBIC PHOTOSYNTHETIC BACTERIUM Rhodopseudomonas palustris NU51
    (PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2011) Selimoglu, Hatice; Ozturk, Ayten; Arisoy, Munevver; Abdullah, Meysun I.
    Dichlorvos (DDVP) is a very toxic pesticide intentionally released into the environment, and its use raises public health and environmental concerns. Nevertheless, it is still widely used in Turkey. In this study, the biosorption of DDVP from aqueous solutions on dehydrated cells of Rhodopseudomonas palustris NU51 was studied as a function of pH, temperature, initial DDVP and biomass concentration. R. palustris NU51 strain belongs to the widely spread and the eco-friendly Rhodopseudomonas species. The best uptake was observed at pH 6.0 and 35 degrees C. As the concentration of biomass has increased, the DDVP uptake has increased from 18.7 to 31.17%, but the concentration of pesticide has decreased. When these results were applied to both Langmuir and Freundlich isotherms, the adsorption data provided an excellent fit to both isotherms and showed good agreement to Scatchard analysis. We could conclude that R. palustris NU51 strain is an excellent bacterium for the removal of pesticides and could be successfully used in wastewater treatments.
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    Characterization of the biosorption of fast black azo dye K salt by the bacterium Rhodopseudomonas palustris 51ATA strain
    (Univ Catolica De Valparaiso, 2020) Ozturk, Ayten; Bayol, Emel; Abdullah, Meysun, I
    Background: Removal of dyes from wastewater by microorganisms through adsorption, degradation, or accumulation has been investigated. Biological methods used for dye treatment are generally always effective and environmentally friendly. In this study, biosorption of the Fast Black K salt azo dye by the bacterium Rhodopseudomonas palustris 51ATA was studied spectrophotometrically, at various pH (2-10), temperatures (25 degrees C, 35 degrees C, and 45 degrees C) and dye concentrations (25-400 mg L-1). Results: The bacterial strain showed extremely good dye-removing potential at various dye concentrations. IR studies at different temperatures showed that the dye was adsorbed on the bacterial surface at lower temperatures. Characteristics of the adsorption process were investigated by Scatchard analysis at 25 degrees C and 35 degrees C. Scatchard analysis of the equilibrium binding data for the dye on this bacterium gave rise to linear plots, indicating that the Langmuir model could be applied. The regression coefficients obtained for the dye from the Freundlich and Langmuir models were significant and divergence from the Scatchard plot was observed. Conclusion: The adsorption behavior of the dye on this bacterium was expressed by the Langmuir, Freundlich, and Temkin isotherms. The adsorption data with respect to various temperatures provided an excellent fit to the Freundlich isotherm. However, when the Langmuir and Temkin isotherm models were applied to these data, a good fit was only obtained for the dye at lower temperatures, thus indicating that the biosorption ability of R. palustris 51ATA is dependent on temperature, pH, and dye concentration. (C) 2020 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. All rights reserved.
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    Effect of molasses on hydrogen production by a new strain Rhodoplanes piscinae 51ATA
    (Pergamon-Elsevier Science Ltd, 2022) Canpolat, Elif; Ozturk, Ayten
    The production of hydrogen using microorganisms is an environment-friendly and less energy-intensive way of producing hydrogen. Rhodoplanes piscinae is a photosynthetic bacterium with the ability of hydrogen production under photosynthetic conditions. In this study, a new strain 51ATA was isolated from Lake Akkaya, Nigde, Turkey that is exposed to some industrial effluent charges. The new strain was identified as R. piscinae by phylogenetic analysis of the 16S ribosomal DNA (rDNA) sequence. The quality of molasses as a substrate for hydrogen production was evaluated by comparing it with other substrates, such as glucose and acetate. Five different culture media of various concentrations (1.0 g/L, 2.0 g/L, 5.0 g/L, 10 g/L, and 20 g/L) for each substrate were used. Results have shown that molasses was the best substrate for the biohydrogen production. The highest amount of biohydrogen obtained from each (20 g/L) substrate was (1.27 L H-2/L from molassescontaining culture), (0.72 L H-2/L from glucose-containing culture), and acetate-containing culture (0.21 L H-2/L) respectively. From these results, we could conclude that R.piscinae 51ATA strain is as good as the other bacterial species used for hydrogen production and may be considered as a high potential strain for hydrogen production when used in combination with molasses under phototrophic conditions. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
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    Evaluation of Interactions Among Aphids, Endosymbionts, and Host Plants: A Foresight for the Future
    (2022) Ergın, Gülay Olcabey; Ozturk, Ayten; Görür, Gazi
    Insects, the most common and most successful animals on earth, establish long-term and stable ecological relationships with bacteria. Aphids (Hemiptera: Aphididae) are an insect group of agri cultural importance that can feed on many herbaceous, shrubs, and woody plants as hosts and are also in close relationship with endosymbiont bacteria. It is seen that aphid is going to further increase their current pest potential in the near future due to their high adaptability and rapid reproduction ability. In order to be effective and successful in the biological control of aphids, many features of aphids are required to be known and clarified. Therefore, determining the interactions among aphid, host plant, and endosymbiont in this relationship might make biological control of aphids more effective. In this review, what is known about the relationship among aphids, the primary endosymbiotic bacterium Buchnera aphidicola, and the host plant is examined, and the possibilities of using symbiont bacteria in the biological control of aphids are discussed.
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    The Activity of Oxygenic Photosynthetic Microbial Consortia on Different Granites
    (FOUNDATION ENVIRONMENTAL PROTECTION & RESEARCH-FEPR, 2014) Ozturk, Ayten; Karaca, Zeki; Unsal, Tuba
    Deterioration of stone is a combined process caused by physical, chemical and biological factors especially, microbial growth. Various microorganisms are playing a key role in the weathering of historical artifacts, buildings, and monuments made of granite, marble, and other dimension stones. In this study, the biodeterioration of three types granite, Blue Pearl from Norway, Pergamon Grey from Turkey, and Rosa Porrino from Spain were studied for thirty days under laboratory conditions. The results showed that two of the granite surfaces, Pergamon Grey and Rosa Porrino, supported a heavy colonization of phototrophic microbial consortia. These results also showed that filamentous phototrophic microorganisms were dominant on the surfaces of the granites and indicated that the porosity, the availability of water and chemical composition of the granite have encouraged colonization and caused modification on the surfaces. The filamentous aggregates, possibly calcified fibrillar bodies in the inner parts of granites were also detected by SEM studies.