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Full-Text Articles in Life Sciences

Characterization Of Ammonia Oxidizing Bacteria In An Activated Sludge Plant Using A Fluorescent In Situ Hybridization Method, Gülnur Coşkuner Jan 2004

Characterization Of Ammonia Oxidizing Bacteria In An Activated Sludge Plant Using A Fluorescent In Situ Hybridization Method, Gülnur Coşkuner

Turkish Journal of Biology

The spatial arrangement of functionally important ammonia oxidizing bacteria (AOB) in activated sludge flocs is largely unknown and activated sludge flocs are regarded as heterogeneous agglomerations of bacterial communities. This study aimed to determine both the location of AOB microcolonies within flocs and the size variation of these microcolonies based on their location. Fluorescent in situ hybridization (FISH) was used in combination with a confocal scanning laser microscope (CSLM) to achieve these goals. Grab samples taken from a full-scale plug flow wastewater treatment plant were examined with probes targeted to AOB b-Proteobacteria (Nso1225) and a genus specific probe targeted to …


Isolation And Characterization Of Aerobic Denitrifiers From Agricultural Soil, Ebru Çelen, Mehmet Aki̇f Kiliç Jan 2004

Isolation And Characterization Of Aerobic Denitrifiers From Agricultural Soil, Ebru Çelen, Mehmet Aki̇f Kiliç

Turkish Journal of Biology

Denitrification is generally considered an anaerobic process. However, in recent years it has been shown that bacteria can also reduce nitrate to nitrite under aerobic conditions. The characterization of biologically available nitrogen forms and their biological cycling mechanisms is important for ecological and agricultural implications. In this study, aerobic nitrate reducers were isolated from greenhouse soil. Using a nitrate reduction assay, it was found that 39 out of 60 isolates can reduce nitrate to nitrite under aerobic conditions. Five of those 39 isolates were selected for further characterization of their aerobic nitrate reduction activity. Four of those 5 isolates were …


The Effect Of Sex On Ischemia - Reperfusion Induced Arrhythmias And The Role Of Atp - Dependent Potassium Channel Blockage, Ersöz Gonca, Eylem Suveren Ti̇ryaki̇, Ömer Bozdoğan Jan 2004

The Effect Of Sex On Ischemia - Reperfusion Induced Arrhythmias And The Role Of Atp - Dependent Potassium Channel Blockage, Ersöz Gonca, Eylem Suveren Ti̇ryaki̇, Ömer Bozdoğan

Turkish Journal of Biology

The presence of more ATP-dependent potassium channels in females has been thought to play an important role in protection against myocardial ischemia. In this study, we investigated whether there is a difference in the severity of ischemia and reperfusion induced arrhythmias due to sex and, if there is, what the role of ATP-dependent potassium channel in this difference is. The left anterior descending coronary artery in rats was ligated and arrhythmias were recorded in ECG during 6 min. of ischemia and reperfusion. The duration of arrhythmias was shorter in females than in corresponding males. Glibenclamide was effective in decreasing the …


An Electrophoretic Study On Esterase And Blood Serum Proteins Of The Water Vole, Arvicola Terrestris (L., 1758) (Mammalia: Rodentia), In Kırşehir Province, Ceren İyi̇gün, Reyhan Çolak Jan 2004

An Electrophoretic Study On Esterase And Blood Serum Proteins Of The Water Vole, Arvicola Terrestris (L., 1758) (Mammalia: Rodentia), In Kırşehir Province, Ceren İyi̇gün, Reyhan Çolak

Turkish Journal of Biology

Esterase enzymes from 30 specimens of Arvicola terrestris in 4 localities in Kırşehir province were examined using starch gel electrophoresis and blood serum proteins from 27 specimens using SDS-PAGE. It was determined that the esterase enzyme had 2 alleles (A and B), which were coded by 1 locus. A and B allele frequencies were 0.362 and 0.638, respectively. The heterozygosity level was 0.5. It was determined that there were variations in the globulin, prealbumin and postalbumin regions, while the albumin region was monomorphic. There were 6-13 bands in the globulin region, 1-2 bands in the postalbumin zone and 2-4 bands …


Evaluation Of Toxicity Of Tannery Effluent On Plankton Community Structure: A Multispecies Microcosm Study Ii, Yalavarthi Naga Koteswari, Ravichandran Ramanibai Jan 2004

Evaluation Of Toxicity Of Tannery Effluent On Plankton Community Structure: A Multispecies Microcosm Study Ii, Yalavarthi Naga Koteswari, Ravichandran Ramanibai

Turkish Journal of Biology

Laboratory experiments were conducted to evaluate the dose-dependent response of tannery effluents on plankton community structure using polyurethane foam (PF) as artificial substrate. Naturally derived planktonic communities on PF provided colonists for the development of new communities under stress conditions in the laboratory. Predictions of colonization rate, taxonomic richness and relative abundance in a series of microcosms dosed with a gradient of tannery effluent from 20% to 35% concentration were assessed after the initial dosage study (1% to 15%). Changes in taxonomic composition occur at high levels of stress. End points responding at increasing levels of stress are declines in …


First Record Of A Npv Isolated From Spodoptera Littoralis (Boisd.) (Lepidoptera: Noctuidae) In Turkey And Its Molecular Identification According To The Partial Lef-8 Gene, Umut Toprak, M. Oktay Gürkan Jan 2004

First Record Of A Npv Isolated From Spodoptera Littoralis (Boisd.) (Lepidoptera: Noctuidae) In Turkey And Its Molecular Identification According To The Partial Lef-8 Gene, Umut Toprak, M. Oktay Gürkan

Turkish Journal of Biology

Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) is an important pest in Turkey and causes extensive economic losses in many cultivated crops. The viruses within the family Baculoviridae are specific pathogens of insects. The nucleopolyhedroviruses (NPVs), 1 of the 2 genera of this family, have been isolated from many insect orders, primarily from the lepidopterans. In our study, a local NPV was isolated from the larvae of Spodoptera littoralis fed in the cotton fields in southern Turkey (Mersin). For the molecular identification of the virus, polyhedra (occlusion bodies [OBs]) were isolated from insects and total DNA extraction was performed using a commercial …


Antibacterial Activities Of Some Plant Extracts Utilized In Popular Medicine In Palestine, Bassam Abu-Shanab, Ghaleb Mohammad Adwan, Dahood Abu-Safiya, Naser Jarrar, Kamel Adwan Jan 2004

Antibacterial Activities Of Some Plant Extracts Utilized In Popular Medicine In Palestine, Bassam Abu-Shanab, Ghaleb Mohammad Adwan, Dahood Abu-Safiya, Naser Jarrar, Kamel Adwan

Turkish Journal of Biology

The antibacterial activities of hot water, methanol and ethanol extracts of 5 plant extracts utilized in Palestine in popular medicine were studied. The dried extracts of Syzyium aromaticum (Myrtaceae) (seed), Cinnamomum cassia (Lauraceae) (cassia bark, Chinese cinnamon) (bark), Salvia officinalis (Lamiaceaea) (leaf), Thymus vulgaris (Lamiaceaea) (leaf) and Rosmarinus officinalis (Labiatae) (leaf) were tested in vitro against 4 bacterial species by disk diffusion and micro-dilution. The patterns of inhibition varied with the plant extract, the solvent used for extraction, and the organism tested. Methicillin-resistant Staphylococcus aureus (MRSA) and Bacillus subtilis ATCC 6633 were the most inhibited microorganisms. S. aromaticum extract was …


Cellular Functions Of The 26s Proteasome, Azmi̇ Yerli̇kaya Jan 2004

Cellular Functions Of The 26s Proteasome, Azmi̇ Yerli̇kaya

Turkish Journal of Biology

The 26S proteasome plays a critical role in many cellular processes by degrading a wide range of both short-lived and long-lived proteins. In this review, proteasome structure and the mechanisms of substrates targeting to the 26S proteasome are described. In addition, this review focuses on the cellular functions that are affected after inhibition of the proteasome, including immune-response, cell-cycle, and transcription. The proteasome is involved in these cellular processes because it degrades numerous short-lived proteins and regulatory proteins that control these cellular functions. Even though it is known that inhibition of the 26S proteasome results in the induction of the …


In Vitro Antifungal Activity Of Strains Of Trichoderma Harzianum, Çi̇ğdem Küçük, Meri̇h Kivanç Jan 2004

In Vitro Antifungal Activity Of Strains Of Trichoderma Harzianum, Çi̇ğdem Küçük, Meri̇h Kivanç

Turkish Journal of Biology

Interactions between Trichoderma harzianum strains and some soilborne plant pathogens (Gaeumannomyces graminis var. tritici, Fusarium culmorum and F. moniliforme) were studied on PDA medium. All T. harzianum strains tested produced a metabolite that inhibited growth of plant pathogenic fungi on PDA medium. When grown in liquid cultures containing laminarin, chitin or fungal cell walls as sole carbon sources, 2 strains of T. harzianum produced 1,3-\beta-glucanase and chitinase in the medium. Higher levels of these enzymes were induced by T. harzianum T15.


Production Of Pullulan From Beet Molasses And Synthetic Medium By Aureobasidium Pullulans, Yekta Göksungur, Asli Uçan, Ulgar Güvenç Jan 2004

Production Of Pullulan From Beet Molasses And Synthetic Medium By Aureobasidium Pullulans, Yekta Göksungur, Asli Uçan, Ulgar Güvenç

Turkish Journal of Biology

The production of pullulan from molasses and synthetic medium by Aureobasidium pullulans P56 in batch culture was investigated. Among the pretreatments of molasses used to increase polysaccharide production, sulfuric acid + activated carbon treatment gave better results with regard to polysaccharide concentration, polysaccharide yield and sugar utilization. A maximum polysaccharide concentration of 21.4 g l^{-1} and a pullulan concentration of 16.7 g l^{-1} were obtained in synthetic medium whereas 35.0 g l^{-1} of polysaccharide and 16.9 g l^{-1} of pullulan were obtained in molasses medium containing 50 g l^{-1} of initial sugar at pH 7.5. The highest pullulan contents of …


The Mechanism Of Inhibition Of Human Erythrocyte Catalase By Azide, Yasemi̇n Aksoy, Mevhi̇be Balk, Hamdi̇ Öğüş, Nazmi̇ Özer Jan 2004

The Mechanism Of Inhibition Of Human Erythrocyte Catalase By Azide, Yasemi̇n Aksoy, Mevhi̇be Balk, Hamdi̇ Öğüş, Nazmi̇ Özer

Turkish Journal of Biology

In order to elucidate the kinetic mechanism of human erythrocyte catalase a well-known substrate, H_2O_2 and inhibitor azide were used. The catalase-mediated conversion of H_2O_2 to H_2O and O_2, in the presence and absence of azide, was studied in 50 mM phosphate buffer pH 7.0 at 37 ºC under conditions where the peroxidation side reaction (RH_2 + H_2O_2  R + 2H_2O) is negligible ([H_2O_2] =< 25 mM; assay time, 10 s). The kinetics conformed to the Michaelis-Menten model. Lineweaver-Burk plots for H_2O_2 at different fixed concentrations of azide were linear and intersected on the abscissa indicating a noncompetitive or irreversible type of inhibition. To identify the inhibition type Vm vs. [E] plots were constructed at different [N_3-]. The plots were linear and converged at the origin, indicating that N_3- is a noncompetitive inhibitor. Using a non-linear curve-fitting program, the kinetic parameters were calculated. The K_m value for H_2O_2, and the K_i value for azide were found to be 10.97 ± 1.46 mM and 1.107 ± 0.093 µM, respectively.


Influence Of Arbuscular Mycorrhiza On Some Physiological Growth Parameters Of Pepper, Semra Demi̇r Jan 2004

Influence Of Arbuscular Mycorrhiza On Some Physiological Growth Parameters Of Pepper, Semra Demi̇r

Turkish Journal of Biology

Arbuscular Mycorrhiza (AM) is a symbiotic association between plant roots and certain soil fungi. Mycorrhiza establishment is known to modify several aspects of plant physiology such as mineral nutrient composition, hormonal balance, and C allocation patterns. In this study, the effect of the Arbuscular Mycorrhizal fungus Glomus intraradices Schenck & Smith on the physiological growth parameters of pepper (Capsicum annuum L. cv Cetinel-150) plants was investigated. To explain the physiological growth of these plants, some physiological growth parameters were determined in the shoots and leaves of mycorrhizal (M) and nonmycorrhizal (NM) plants such as the P and dry matter (d.m.) …


Genetic Analysis Of Bifunctional Genes From Rumen Bacterium, Emi̇n Özköse, İsmai̇l Akyol, Ercan Efe, M. Sai̇t Eki̇nci̇ Jan 2004

Genetic Analysis Of Bifunctional Genes From Rumen Bacterium, Emi̇n Özköse, İsmai̇l Akyol, Ercan Efe, M. Sai̇t Eki̇nci̇

Turkish Journal of Biology

Deletion of domain B of the xynD gene was performed and the nucleotide sequence of this domain was compared with other enzyme sequences to reveal its function. Ruminococcus flavefaciens DNA fragment encodes xylanase and \beta-(1,3-1,4)-glucanase (xynD) activities with 3 domains (A, B, C). The amino-terminal domain (A) is related to family G xylanase while the carboxy-terminal domain (C) is related to family 16 \beta-(1,3-1,4)-glucanase. These 2 domains are connected by a region (B) of unknown function. Deletion of domain B leads to increased thermosensitivity of the enzyme and also in a 2-3-fold increase in \beta-(1,3-1,4)-glucanase activity. A survey of the …


Effects Of Some Pesticides On Spore Germination And Larvicidal Activity Of Bacillus Thuringiensis Var. Israelensis And Bacillus Sphaericus 2362 Strain, İsmet Berber, Cumhur Çökmüş, Ekrem Atalan Jan 2004

Effects Of Some Pesticides On Spore Germination And Larvicidal Activity Of Bacillus Thuringiensis Var. Israelensis And Bacillus Sphaericus 2362 Strain, İsmet Berber, Cumhur Çökmüş, Ekrem Atalan

Turkish Journal of Biology

The effects of 9 commercial pesticides used commonly in agriculture on spore germination and larvicidal activity of the mosquito pathogenic B. thuringiensis var. israelensis and B. sphaericus 2362 strain were examined. Six of the pesticides was had an inverse impact on spore germination and growth of the test strains. It was determined that the pesticides with the most adverse effect were copper sulfate, methiocarb, and dalapon on spore germination of the microorganisms. Higher concentrations or MIC values of the pesticides reduced the heat-resistant spore numbers of both bioinsecticides, suppressing spore germination. These results indicated that the spores of the bacteria …


A Morphological Study Of The Venom Apparatus Of The Spider Allopecosa Fabilis (Araneae, Lycosidae), Külti̇ği̇n Çavuşoğlu, Meltem Maraş, Abdullah Bayram Jan 2004

A Morphological Study Of The Venom Apparatus Of The Spider Allopecosa Fabilis (Araneae, Lycosidae), Külti̇ği̇n Çavuşoğlu, Meltem Maraş, Abdullah Bayram

Turkish Journal of Biology

The morphological structure of the venom apparatus of Allopecosa fabrilis was studied using scanning electron microscopy (SEM). The venom apparatus is situated in the prosoma and is composed of a pair of chelicerae and venom glands. Each chelicera consists of 2 parts, a stout basal part covered by hair, and a movable fang. A venom pore is situated on the subterminal part of the fang. Just below the fang, there is a cheliceral groove next to the teeth. Each side of the groove is covered with cuticular teeth. The venom glands are large and roughly cylindrical. Each gland is surrounded …


The Use Of Ram Horn Hydrolysate As A Supplement For Glycerol Production By Yeast, Esabi̇ Başaran Kurbanoğlu, Namudar İzzet Kurbanoğlu Jan 2004

The Use Of Ram Horn Hydrolysate As A Supplement For Glycerol Production By Yeast, Esabi̇ Başaran Kurbanoğlu, Namudar İzzet Kurbanoğlu

Turkish Journal of Biology

This study describes the interesting potential of ram horns to be used as a supplement for glycerol production in batch fermentation. The use of ram horn hydrolysate (RHH) as a supplement for glycerol production was investigated using baker’s yeast, Saccharomyces cerevisiae. For this purpose, RHH was first produced. The production and chemical composition of the RHH was as described in our previous study. The effects of different concentrations (1 to 10% v/v) of RHH on the production of glycerol were investigated, and 8% RHH was found to be optimal. The content of glycerol in the culture broth containing RHH (6.3 …


Species Composition And Diversity Of Epipelic Algae In Çatal Lake (Şebinkarahisar-Giresun, Turkey), Bülent Şahi̇n Jan 2004

Species Composition And Diversity Of Epipelic Algae In Çatal Lake (Şebinkarahisar-Giresun, Turkey), Bülent Şahi̇n

Turkish Journal of Biology

The epipelic algae of Çatal Lake were studied between June and October 2002. Fifty-three taxa (39 belonging to Bacillariophyta, 8 to Chlorophyta, 5 to Cyanophyta and 1 to Euglenophyta) were determined. Based on the epipelic algal composition, Çatal Lake can be characterized as eutrophic.