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Biology

TÜBİTAK

2006

Articles 31 - 38 of 38

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Rnf Genes In Purple Sulfur Bacterium Allochromatium Vinosum, H. Benan Di̇nçtürk, Volkan Demi̇r Jan 2006

Rnf Genes In Purple Sulfur Bacterium Allochromatium Vinosum, H. Benan Di̇nçtürk, Volkan Demi̇r

Turkish Journal of Biology

Allochromatium vinosum is a photosynthetic, diazotrophic purple sulfur bacterium that oxidizes reduced sulfur compounds hydrogen sulfide, elemental sulfur and thiosulfide. In this article, we report the presence of rnf genes in Allochromatium vinosum, some of which have been reported to take part in nitrogen fixation in some species.

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Non-Histone Proteins And The Mediator Complex Are Essential For The Transcription Of Hxt2 And Hxt4 Genes In Saccharomyces Cerevisiae, Si̇nem Güzelvardar, Sezai̇ Türkel Jan 2006

Non-Histone Proteins And The Mediator Complex Are Essential For The Transcription Of Hxt2 And Hxt4 Genes In Saccharomyces Cerevisiae, Si̇nem Güzelvardar, Sezai̇ Türkel

Turkish Journal of Biology

Transcriptional activation of HXT2 and HXT4 genes require rapid reorganization of the chromatin structure on the promoter regions of these genes. In this study, it was found that the transcription of HXT2 and HXT4 genes decreased 4- to 7-fold in the yeast strain that does not contain the non-histone proteins 6A and 6B (Nhp6A/B). In addition, results of this research indicated that Nhp6A/B are required for the rapid derepression and activation of HXT2 and HXT4 transcription upon glucose signaling. Furthermore, it was found that Med2p, which provides the connection between the transcriptional activators and the basal transcription factors, is also …

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Antimicrobial Activities Of The Extracts Of Marine Algae From The Coast Of Urla (İzmir, Turkey), İnci̇ Tüney, Bi̇lge Hi̇lal Çadirci, Di̇lek Ünal, Atakan Sukatar Jan 2006

Antimicrobial Activities Of The Extracts Of Marine Algae From The Coast Of Urla (İzmir, Turkey), İnci̇ Tüney, Bi̇lge Hi̇lal Çadirci, Di̇lek Ünal, Atakan Sukatar

Turkish Journal of Biology

Methanol, acetone, diethyl ether, and ethanol extracts of 11 seaweed species from the coast of Urla were tested in vitro for their antimicrobial activities against Candida sp., Enterococcus faecalis, Staphylococcus aureus, Streptococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli with the disc diffusion method. Diethyl ether was the best solution for extracting the effective antimicrobial materials from the algae species used in this experiment, with the exception of D. linearis, for which ethanol was the most effective extraction solution. Diethyl ether extracts of fresh Cystoseira mediterranea, Enteromorpha linza, Ulva rigida, Gracilaria gracilis, and Ectocarpus siliculosus showed effective results against all test …

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Antibacterial Activity Of Four Plant Extracts Used In Palestine In Folkloric Medicine Against Methicillin-Resistant Staphylococcus Aureus, Bassam Abu-Shanab, Ghaleb Mohammad Adwan, Naser Jarrar, Awni Abu-Hijleh, Kamel Adwan Jan 2006

Antibacterial Activity Of Four Plant Extracts Used In Palestine In Folkloric Medicine Against Methicillin-Resistant Staphylococcus Aureus, Bassam Abu-Shanab, Ghaleb Mohammad Adwan, Naser Jarrar, Awni Abu-Hijleh, Kamel Adwan

Turkish Journal of Biology

Ethanolic and hot water extracts from 4 different plant species used in Palestine in popular medicine for the treatment of several ailments of microbial and non-microbial origin were evaluated for potential antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Both water and ethanol extracts of Mentha longifolia, Melissa officinalis and Rosa damascena were effective on MRSA. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the ethanolic extract of M. longifolia and M. officinalis were in the range of 3.125 to 12.50 mg/ml and 12.50 to 25.00 mg/ml, respectively. The ethanolic extract with the greatest antimicrobial activity was …

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Effectiveness Of The Entomopathogenic Nematodes Heterorhabditis Bacteriophora And Steinernema Feltiae Against Tenebrio Molitor (Yellow Mealworm) Larvae In Different Soil Types At Different Temperatures, Alper Susurluk Jan 2006

Effectiveness Of The Entomopathogenic Nematodes Heterorhabditis Bacteriophora And Steinernema Feltiae Against Tenebrio Molitor (Yellow Mealworm) Larvae In Different Soil Types At Different Temperatures, Alper Susurluk

Turkish Journal of Biology

The efficiency of the entomopathogenic nematodes Steinernema feltiae Tur-S3 and Heterorhabditis bacteriophora Tur-H2, isolated in Turkey, against larvae of Tenebrio molitor L. was investigated in different soil type and temperature conditions. Sterilized and non-sterilized silver sand, clay-loam soil, and compost soil were tested, each at 12, 18, and 24 ºC. Temperature had the greatest effect on the mortality of T. molitor larvae caused by both nematode species. The efficiency of the 2 nematodes was greater in sterile than in nonsterile conditions, and was greater in sandy soils than in clay soils. The results showed that Steinernema feltiae was more efficient …

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The Relationship Between Seasonal Variation In Phytoplankton And Zooplankton Densities In Hirfanlı Dam Lake (Kırşehir, Turkey), Tülay Baykal, Selahatti̇n Salman, İlkay Açikgöz Jan 2006

The Relationship Between Seasonal Variation In Phytoplankton And Zooplankton Densities In Hirfanlı Dam Lake (Kırşehir, Turkey), Tülay Baykal, Selahatti̇n Salman, İlkay Açikgöz

Turkish Journal of Biology

Phytoplankton and zooplankton densities in Hirfanlı Dam Lake were studied between July 1999 and June 2000. In addition, phytoplankton biomass was measured using chlorophyll a concentration. The density of Cladocera at the surface and that of Rotifera at the bottom were low in the summer months. For phytoplankton, Cyclostephanos dubius (Fricke) Round was dominant. The variation in the density of organisms did not follow a known pattern. Species composition, seasonal distribution and species density variations show that the lake was advanced mesotrophic. The lake was alkaline and, from time to time, there was an odor in the littoral regions where …

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Chemical Composition Of The Essential Oil Of Salvia Aethiopis L., Medi̇ne Güllüce, Hakan Özer, Özlem Bariş, Di̇mi̇tra Daferera, Fi̇kretti̇n Şahi̇n, Moschos Polissiou Jan 2006

Chemical Composition Of The Essential Oil Of Salvia Aethiopis L., Medi̇ne Güllüce, Hakan Özer, Özlem Bariş, Di̇mi̇tra Daferera, Fi̇kretti̇n Şahi̇n, Moschos Polissiou

Turkish Journal of Biology

The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Salvia aethiopis was analyzed by employing GC-MS. Thirty-two components (98.0% of the total oil) were identified in the essential oil of S. aethiopis. The main components of this oil were germacrene D (29.0%), \alpha-copaene (19.8%), \beta-cubebene + \beta-elemene (9.9%), bicyclogermacrene (9.3%), \delta cadinene (8.7%), and \beta-caryophyllene (7.3%).

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Karyological Observation Of Red Mullet (Mullus Barbatus Linnaeus, 1758), Serkan Saygun, İsmi̇han Karayücel, Recep Bi̇rcan Jan 2006

Karyological Observation Of Red Mullet (Mullus Barbatus Linnaeus, 1758), Serkan Saygun, İsmi̇han Karayücel, Recep Bi̇rcan

Turkish Journal of Biology

The number and structure of red mullet chromosomes (Mullus barbatus Linnaeus, 1758) were investigated and the species karyotype was analyzed. Specimens were obtained by trawl from the coast of Zonguldak, Turkey. A colchicine solution, 0.1 mg/g of body weight, was intramuscularly injected dorsally, and intraperitoneally injected ventrally. Slides were prepared from gill and fin epithelial tissues. Results of the conventional staining method showed that this species has 2n = 44 diploid chromosomes.

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