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2004

TÜBİTAK

Articles 331 - 337 of 337

Full-Text Articles in Life Sciences

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.

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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 …

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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 …

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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.) …

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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 …

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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.

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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 …

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