Determination of carotenoids in two algae species from the saline water of Kapulukaya reservoir by HPLC

BASARAN KANKILIC, Gokben/0000-0001-7551-4899WOS: 000424808500007The local algae species, Chlorella vulgaris and Scenedesmus regularis, from a highly saline water body of Kapulukaya Reservoir were isolated to analyze their carotenoid composition and content using HPLC method. The gradient solvent system of methanol-acetonitrile-water (84:14:2, v/v/v) and methylene chloride (100%), used to resolve a range of carotenoids from the saponified cells, proved an acceptable separation as inferred from the retention factor (k) ranging between 0.75 and 7.76 and the separation factor (alpha) values greater than 1. Resolution peaks assigned to carotenoids, 21 for C. vulgaris extracts and 22 for S. regularis extracts, were reached within the duration time of 45 min. Main carotenoids identified either tentatively or positively were all-trans-lutein, 9- or 9'-cis-lutein, 13- or 13'-cis-lutein, cis-lutein, All-trans-alpha-carotene, 9- or 9'-cis-alpha-carotene, All-trans-beta-carotene, 9- or 9'-cis-beta-carotene in the species except for all-trans-beta-cryptoxanthin found only in S. regularis. Auroxanthin, neochrome, neoxanthin, and cis-neoxanthin were identified as epoxy-containing compounds. Quantitatively, C. vulgaris was distinguished to have greater amount of lutein and cis-isomers (2.74 mg/g), 77.89% while S. regularis was predominated by beta-carotene and cis isomers as major component, being 80.72% (5.76 mg/g) in total carotenoids (TC). In terms of total carotenoids, the species were considered to be efficient sources for further practical applications.Kirikkale UniversityKirikkale University [2011/011]The authors gratefully thank Kirikkale University Research Fund for their financial support, Project number 2011/011

Phragmites australis: An alternative biosorbent for basic dye removal

WOS: 000367093600012This study is aimed at investigating the removal of methylene blue (MB) from aqueous solutions using a reed species, Phrag-mites australis as an adsorbent. P. australis was modified by means of a chemical treatment, assuring the alteration of hydroxyl groups to sulphonyl groups. Experiments were performed in the batch mode to determine the adsorption dynamics of the modified and untreated P. australis. The impact of several influential parameters such as initial pH, initial dye concentration and contact time on the adsorption capacity of P. australis was evaluated. The adsorption capacity of raw P. australis was found to improve significantly by modification reaction. The maximum sorption capacities of the raw and modified biomass were found to be 22.7 mg/g and 46.8 mg/g at initial MB concentration of 250 ppm, biosorbent dosage 0.25 g and initial dye solution of pH of 6.5, respectively. Dye adsorption equilibrium data were fitted well to the Langmuir isotherm rather than the others. The rate of adsorption followed the pseudo second-order kinetic model. Thermodynamic parameters for both raw and modified biomass showed that the adsorption of MB was favorable and spontaneous. Results showed that both P. australis and its modified form have a potential as an eco-friendly adsorbent for the removal of methylene blue from aqueous solution. (C) 2015 Elsevier B.V. All rights reserved.Kirikkale UniversityKirikkale University [2015/45]The authors gratefully thank Kirikkale University Research Fund for their financial support, Project number 2015/45

Assessment of heavy metal levels in sediment samples of Kapulukaya Dam Lake (Kirikkale) and lower catchment area

KADIOGLU, Yusuf Kagan/0000-0002-7894-2220WOS: 000321123800042PubMed: 23315100In this study, the concentrations of 13 elements (Al, Fe, Mn, Cr, Ni, Zn, Co, As, Pb, Cu, Mo, Hg, and Cd) were determined in the sediments of three different sites in the Kapulukaya Dam Lake between May 2007 and November 2008. They ranged from 1.47 to 4.64 for Al, 0.92 to 3.48 for Fe (in percent), 326.60 to 1053.00 for Mn, 98.00 to 1,116.00 for Cr, 24.70 to 127.10 for Ni, 14.80 to 124.20 for Zn, 11.0 to 43.20 for Co, 5.00 to 29.30 for Cu, 9.10 to 69.70 for As, 8.60 to 34.00 for Pb, 2.50 to 5.20 for Mo, 1.00 to 1.60 for Hg, and 0.50 to1.80 for Cd in microgram per gram dry weight sediment. The contamination degree of the sediment was assessed on the basis of enrichment factor and corresponding sediment quality guideline. The calculated enrichment factors (EF, measured metal vs. background concentrations) indicated that the effect of man-made activities on the occurrence of concentrations could be accounted for the majority of heavy metals namely Mn, As, Ni, Cu, Zn, Cr, Co, Mo, and Cd, whereas such affect was not detected for Hg and Pb. The maximum values of the EF were represented by As, minimum values by Hg at all sites. Mean EF values were 36.60 and 0.70 for As and Hg, respectively. This study has clearly assessed a certain level of heavy metal pollution in the region, based particularly on the findings from sediment

DETERMINATION OF THE CHEMICAL COMPOSITION IN THE KAPULUKAYA RESERVOIR SEDIMENT BY USING THE PEDXRF METHOD

KADIOGLU, Yusuf Kagan/0000-0002-7894-2220WOS: 000291840300004In this study a multi-element analysis was conducted on the contents of the sediments found at three different sites in the Kapulukaya Dam Lake between May 2007 and November 2007. The elemental analysis of the sediment samples was carried out by using the technique of Polarized Energy Dispersive X-ray Fluorescence (PEDXRF). Of twenty three elements, Cr, Ni, Hg demonstrated high levels of contamination at all sites and As at site 3 according to the criteria set for threshold effect concentrations and probable effect concentrations. The accuracy and precision of the technique employed for conducting the chemical analysis were demonstrated by analyzing the G01-GSD-09 sediment and the K04-NIST-2704 river sediment. Measured concentrations reached at average of 92.7 % and 89.9 % accuracy on the standards used, respectively. The present investigation revealed the effectiveness of this technique in analyzing the sediment content

Two pronounced Chlorella strains for efficient biodiesel feedstock production

WOS: 000474619300003In this study, two indigenous Chlorella strains were evaluated for triacylglycerol (TAG) production and related parameters during 10 days of N-deprivation. The strains were identified based on morphological characteristics and genomic information, named as Chlorella sp. IMU12 and Chlorella sp. IMU17. Time-dependent reduction of growth was accompanied by decreased chlorophyll content, reduced oxygen evolution ratio, and elevated carotenoid content of both strains cultivated in N-free Bold's basal medium. Nitrogen deprivation induced total lipid and neutral lipid content in both strains, supported by FTIR measurement of TAGs. Chlorella sp. IMU17 showed higher production of TAGs as a response to N-deprivation. Strikingly, relative polysaccharide content showed a rapid increase on the first days and a noticeable reduction was recorded especially after 5 days of N-deprivation while TAG production showed a gradual increase during the whole period of N-deprivation in both strains. Starch might be a predominant form of carbon storage in the short term and the continuous increase of TAG production might be supported by degradation of starch in a longer period of N-deprivation. FAME analysis of lipids showed that the saturation level of the fatty acids of both strains meets the European standard EN 14214 requirements. Lastly, N-deprivation stimulated a significant reduction of PUFA production in Chlorella sp. IMU17. Thus, Chlorella sp. IMU17 might stand as a promising candidate for biodiesel feedstock production with its low PUFA content and a concomitant induction of saturation of fatty acids as a clear response to N-deprivation.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112Y029]; Research Fund of Istanbul Medeniyet UniversityIstanbul Medeniyet University [FBA-2012-185]This study was supported by grants from the Scientific and Technological Research Council of Turkey (TUBITAK, Project #112Y029) and the Research Fund of Istanbul Medeniyet University (Project #FBA-2012-185)

An automata networks based preprocessing technique for artificial neural network modelling of primary production levels in reservoirs

Kilic, Hurevren/0000-0003-2647-8451; Kilic, Hurevren/0000-0002-9058-0365WOS: 000244598300011Primary production in lakes and reservoirs develops as a result of complex reactions and interactions. Artificial neural networks (ANN) emerges as an approach in quantification of primary productivity in reservoirs. Almost all of the past ANN applications employed input data matrices whose vectors represent either water quality parameters or environmental characteristics. Most of the time, the components of input matrices are determined using expert opinion that implies possible factors that affect output vector. Major disadvantage of this approach is the possibility of ending-up with an input matrix that may have high correlations between some of its components. In this paper, an automata networks (AN) based preprocessing technique was developed to select suitable and appropriate constituents of input matrix to eliminate redundancy and to enhance calculation efficiency. The proposed technique specifically provides an apriori rough behavioral modeling through identification of minimal AN interaction topology. Predictive ANN models of primary production levels were developed for a reservoir following AN based pre-modeling step. The achieved levels of model precisions and performances were acceptable: the calculated root mean square error values (RMSE) were low; a correlation coefficient (R) as high as 0.83 was achieved with an ANN model of a specific structure. (c) 2006 Elsevier B.V. All rights reserved

Biosorption of mercury(II), cadmium(II) and lead(II) ions from aqueous system by microalgae Chlamydomonas reinhardtii immobilized in alginate beads

WOS: 000241228100004The potential use of the immobilized microalgae (in Ca-alginate) of Chlamydomonas reinhardtii to remove Hg(II), Cd(II) and Pb(II) ions from aqueous solutions was evaluated using bare Ca-alginate bead as a control system. Ca-alginate beads containing immobilized microalgae were incubated for the uniform growth at 22 degrees C for 5 days. Effects of pH, temperature, initial concentration of metal ions and biosorbent dosages on the adsorption of Hg(II), Cd(II) and Pb(II) ions were studied. Adsorption of Hg(II), Cd(II) and Pb(II) ions on the immobilized microalgae showed highest values at around pH 5.0 to 6.0. The adsorption equilibrium was represented with Langnmir and Freundlich adsorption isotherms. The adsorption of these ions on the immobilized microalgae followed second-order kinetics and equilibrium was established in about 60 min. The temperature change in the range of 5-40 degrees C did not affect the adsorption capacities of the immobilized microalgae. The immobilized-algal systems can be regenerated using 2 M NaCl for Hg(II), Cd(II) and Pb(II) ions. (c) 2006 Elsevier B.V. All rights reserved

Synthesis, characterization, biological evaluation, and molecular docking studies of some piperonyl-based 4-thiazolidinone derivatives

Heterocyclic compounds are of particular importance among pharmacologically active compounds. In this study, some piperonyl-based 4-thiazolidinone derivatives (2a-i) were synthesized and characterized by spectroscopic assays. All molecules were tested as enzyme inhibitory factors. These compounds were effective inhibitors of the enzymes acetylcholinesterase (AChE), alpha-glycosidase (alpha-Gly), and the human carbonic anhydrase I and II isoforms (hCA I and II), with K-i values in the range of 8.90-66.51 nM for alpha-Gly, 94.8-289.5 nM for hCA I, 106.3-304.6 nM for hCA II, and 0.55-2.36 nM for AChE. The synthesized molecules were also studied theoretically. Molecular docking calculations were performed to investigate the interaction between the target protein and molecules. CA inhibitor compounds have been clinically used for almost 60 years as antiglaucoma and diuretic drugs. The inhibition of the AChE enzyme results in the blockage of ACh hydrolysis. On the contrary, the design of inhibitor compounds or/and modulators for AChE is of major interest as it is one of the most popular tools to prevent Alzheimer's disease