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Öğe Alkaline protease production by an actinomycete MA1-1 isolated from marine sediments(Springer, 2007) Hames-Kocabas, E. Esin; Uzel, AtacAlkaliphilic actinomycetes isolated from sediment samples of the Izmir Gulf, Turkey were studied for the production of protease activity. Strain MA1-1 was selected as a good alkaline protease producer as measured by the clear zone diameter by the hydrolysis of skim-milk and casein. The alkaline protease production from the marine alkaliphilic actinomycete MA1-1 was studied by using different carbon and nitrogen sources in medium containing glycerol, peptone, KCl, MgSO4, K2HPO4, and trace elements at 30 degrees C for 72 h. Among the different carbon and nitrogen sources, fructose, starch, maltose, D(+) glucose, yeast extract, malt extract, beef extract and peptone provided higher production of protease. Starch was also found to be effective for growth and enzyme production with highest specific activity at 699 U mg(-1). Purification was achieved by adsorption on Diaion HP 20 which resulted in a recovery rate of 68% with a specific activity of 7618 U mg(-1) protein and 40-fold purification. The optimum pH and temperature of the partially purified protease were determined as pH 9.0 and 50 degrees C, but high activity was also observed at pH 8.0-13.0 and 35-50 degrees C. The inhibition profile exhibited by phenylmethylsulphonyl fluoride (PMSF) showed that this enzyme belongs to the serine-protease group.Öğe Biodiversity and bioactivity of some marine sediment derived actinomycetes from Turkey(Elsevier Science Bv, 2012) Ozcan, Kadriye; Aksoy, Semiha Cetinel; Kalkan, Orcun; Uzel, Atac; Hames-Kocabas, E. Esin; Yokes, M. Baki; Bedir, ErdalÖğe Colonization and vertical transmission of Streptococcus mutans in Turkish children(Elsevier Gmbh, Urban & Fischer Verlag, 2008) Hames-Kocabas, E. Esin; Ucar, Fuesun; Ersin, Nazan Kocatas; Uzel, Atac; Alpoz, Ali RizaThe aim of the study was to establish the colonization of Streptococcus mutons and to determine the possibility of intra-familial transmission in a group of Turkish children and their parents. A total of 56 children participated in the study together with their parents (20 fathers and 49 mothers). Saliva samples were collected from the individuals and cultivated on S. mutans selective TYCSB agar. The typical isolates of S. mutans were identified by using classical. microbiological methods, as well as molecular typing of S. mutans clones. which was performed by using AP PCR with OPA5 primer for the detection of transmission. The vertical transmission of salivary S. mutans was detected among 14 mother-father-child, 35 mother-child (one twins) and 6 father-child combinations. The homologies of strain types were recorded as 24% and 16.6% for mother-child and father-child combinations, respectively. A significant positive correlation (p<0.001) was found between the infected children and their parents with high S. mutans counts. (C) 2006 Elsevier GmbH. All rights reserved.Öğe Cultivable sponge-associated actinobacteria: Phylogenetic diversity and antimicrobial activities(Elsevier Science Bv, 2012) Oner, Ozlem; Ekiz, Guner; Hames-Kocabas, E. Esin; Demir, Volkan; Gube, Ozkan; Ozkaya, F. Can; Yokes, M. Baki; Uzel, Atac; Bedir, ErdalÖğe Diversity and antibiotic-producing potential of cultivable marine-derived actinomycetes from coastal sediments of Turkey(Springer Heidelberg, 2013) Ozcan, Kadriye; Aksoy, Semiha Cetinel; Kalkan, Orcun; Uzel, Atac; Hames-Kocabas, E. Esin; Bedir, ErdalMarine environments, especially sediments, are rich sources of actinomycetes that provide many bioactive compounds, primarily antibiotics. The goal of this study was to investigate the diversity of cultivable actinomycetes and their potential to produce antibiotics from sediments collected from the coastal zones of Turkey. Thirty sediment samples were collected from nine different coastal sites in three seas surrounding the Anatolian Peninsula of Turkey. Of the samples, 6 were collected from one site in the Black Sea, 18 from seven sites in the Aegean Sea, and 6 from one site in the Mediterranean Sea. Strains of pure actinomycetes were isolated by modified actinomycetes isolation agar (MAIA), M1 agar, M6 agar, and modified R2A agar. Ethyl acetate extracts and fermentation broths were used for the evaluation of antimicrobial activity against antibiotic resistant test microorganisms. The identification of the isolates was undertaken by 16S rRNA gene sequencing. A total of 261 strains of actinomycetes were isolated, of which 66 (25 %) were active against at least one antibiotic-resistant microorganism. Sixty-five of the actinomycetes isolates with antimicrobial activity were Streptomyces spp. and one was Nocardia sp., which implied that genus Streptomyces was predominant. Whereas MAIA agar was the best medium to recover actinomycetes, M6 agar was superior to others for the isolation of antibiotic-producing strains. Extensive screening of the extracts from the 261 isolates for antimicrobial activities revealed considerable potential to produce antibiotics. These findings imply that actinomycetes from marine sediments of the Anatolian Peninsula coasts have potential for the discovery of novel bioactive compounds.Öğe The effects of different intensities, frequencies and exposure times of extremely low-frequency electromagnetic fields on the growth of Staphylococcus aureus and Escherichia coli O157: H7(Taylor & Francis Inc, 2015) Bayir, Ece; Bilgi, Eyup; Sendemir-Urkmez, Aylin; Hames-Kocabas, E. EsinThe impact of different types of extremely low-frequency electromagnetic fields (ELF-EMF) on the growth of Staphylococcus aureus and Escherichia coli O157:H7 was investigated. The cultures of bacteria in broth media were exposed to sinusoidal homogenous ELF-EMF with 2 and 4mT magnetic intensities. Each intensity for each bacteria was combined with three different frequencies (20, 40 and 50 Hz), and four different exposure times (1, 2, 4 and 6 h). A cell suspension of each experiment was diluted for the appropriate range and inoculated to Mueller-Hinton Agar (MHA) plates after exposure to ELF-EMF. The number of colony forming units (CFU) of both strains was obtained after incubation at 37 degrees C for 24 h. Data were statistically evaluated by one-way analysis of variance (ANOVA), statistical significance was described at p<0.05 and data were compared with their non-exposed controls. Magnetic intensity, frequency and exposure time of ELF-EMFs changed the characteristic responses for both microorganisms. Samples exposed to ELF-EMF showed a statistically significant decrease compared to their controls in colony forming capability, especially at long exposure times. An exposure to 4 mT-20 Hz ELF-EMF of 6 h produced maximum inhibition of CFU compared to their controls for both microorganisms (95.2% for S. aureus and 85% for E. coli).Öğe Increased alkalotolerant and thermostable ribonuclease (RNase) production from alkaliphilic Streptomyces sp M49-1 by optimizing the growth conditions using response surface methodology(Springer, 2013) Demir, Tugce; Gube, Ozkan; Yucel, Mesut; Hames-Kocabas, E. EsinTotal of 171 alkaliphilic actinomycetes were evaluated for extracellular RNase production and Streptomyces sp. M49-1 was selected for further experiments. Fermentation optimization for RNase production was implemented in two steps using response surface methodology with central composite design. In the first step, the effect of independent fermentation variables including temperature, initial pH and process time were investigated. After identification of carbon and nitrogen sources affecting the production by one variable at a time method, concentrations of glucose and yeast extract and also inoculum size were chosen for the second central composite design. A maximum RNase activity was obtained under optimal conditions of 4.14 % glucose concentration, 4.63 % yeast extract concentration, 6.7 x 10(6) spores as inoculum size for 50 ml medium, 42.9 A degrees C, 91.2 h process time and medium initial pH 9.0. Optimum activity of the enzyme is achieved at pH 11 and temperature 60 A degrees C. The enzyme is highly stable at pH range 9.0-12.0 and at 90 A degrees C after 2 h. Statistical optimization experiments provide 2.25 fold increases in the activity of alkalotolerant and thermostable RNase and shortened the fermentation time compared to that of unoptimized condition. The members of Streptomyces can be promising qualified RNase producer for pharmaceutical industries.Öğe Isolation of secondary metabolites from a marine derived Streptomyces sp 9CM17 and investigation of their antimicrobial activities(Elsevier Science Bv, 2012) Ozcan, Kadriye; Uzel, Atac; Hames-Kocabas, E. Esin; Bedir, ErdalÖğe Isolation strategies of marine-derived actinomycetes from sponge and sediment samples(Elsevier Science Bv, 2012) Hames-Kocabas, E. Esin; Uzel, AtacDuring the last two decades, discoveries of new members of actinomycetes and novel metabolites from marine environments have drawn attention to such environments, such as sediment and sponge. For the successful isolation of actinomycetes from marine environments, many factors including the use of enrichment and pre-treatment techniques, and the selection of growth media and antibiotic supplements should be taken into account. High-throughput cultivation is an innovative technique that mimics nature, eliminates undesired, fast-growing bacteria and creates suitable conditions for rare, slow-growing actinomycetes. This review comprehensively evaluates the traditional and innovative techniques and strategies used for the isolation of actinomycetes from marine sponge and sediment samples. (C) 2012 Elsevier B.V. All rights reserved.Öğe LEGIONELLA PNEUMOPHILA: LEGIONNARIES' DISEASE(Nova Science Publishers, Inc, 2010) Uzel, Atac; Hames-Kocabas, E. Esin; Lutsenko, A; Palahniuk, VLegionella pneumophila was recognized as an important human pathogen after the first discovery during an investigation of a pneumonia outbreak among American Legion convention in 1976 in Philadelphia, USA. L. pneumophila is a gram-negative, mesophilic, facultative intracellular parasitic and nonspore-forming rod-shaped bacterium belonging to the gamma-subgroup of proteobacteria. L. pneumophila inhabits natural freshwater environments at low concentration. Along with the transfer from natural aquatic habitats into man-made water systems such as cooling towers, evaporative condensers, water distribution systems, whirlpool spas and hot water tanks, L. pneumophila reaches high cell density and can cause Legionnaires' disease (pneumonic legionellosis) or Pontiac fever (severe influenza-like illness). Infection occurs primarily via the inhalation of L. pneumophila-contaminated aerosols. In aquatic habitats, L. pneumophila cells are intracellular parasites of freshwater protozoa and use a similar mechanism to multiply within mammalian cells. L. pneumophila can also multiply extracellularly within biofilms and can persist within these microbial communities for years. Transmission to human primarily occurs via the inhalation of L. pneumophila containing aerosols. The bacterium enters to human phagocytic cells by coiling or conventional phagocytosis then inhibits phagosome-lysosome fusion and multiplies in the phagosome. A number of virulence factors have been described for L. pneumophila such as surface proteins, secreted factors and putative virulence factors. L. pneumophila can be identified by using cultural, serologic and various molecular techniques such as DNA sequencing and DNA-DNA hybridization. Diagnosis can be made by culture, direct fluorescent antibody staining, serological tests, urinary antigen detection or nucleic acid detection and various subtyping techniques. In order to eradicate L. pneumophila from contaminated water systems several methods are available; Thermal or chemical shock \disinfection, UV irradiation, ozone treatment, silver-copper ionization, anodic oxidation and chlorine dioxide application.Öğe LEGIONELLA PNEUMOPHILA: LEGIONNARIES' DISEASE(Nova Science Publishers, Inc, 2010) Uzel, Atac; Hames-Kocabas, E. Esin; Lutsenko, A; Palahniuk, VLegionella pneumophila was recognized as an important human pathogen after the first discovery during an investigation of a pneumonia outbreak among American Legion convention in 1976 in Philadelphia, USA. L. pneumophila is a gram-negative, mesophilic, facultative intracellular parasitic and nonspore-forming rod-shaped bacterium belonging to the gamma-subgroup of proteobacteria. L. pneumophila inhabits natural freshwater environments at low concentration. Along with the transfer from natural aquatic habitats into man-made water systems such as cooling towers, evaporative condensers, water distribution systems, whirlpool spas and hot water tanks, L. pneumophila reaches high cell density and can cause Legionnaires' disease (pneumonic legionellosis) or Pontiac fever (severe influenza-like illness). Infection occurs primarily via the inhalation of L. pneumophila-contaminated aerosols. In aquatic habitats, L. pneumophila cells are intracellular parasites of freshwater protozoa and use a similar mechanism to multiply within mammalian cells. L. pneumophila can also multiply extracellularly within biofilms and can persist within these microbial communities for years. Transmission to human primarily occurs via the inhalation of L. pneumophila containing aerosols. The bacterium enters to human phagocytic cells by coiling or conventional phagocytosis then inhibits phagosome-lysosome fusion and multiplies in the phagosome. A number of virulence factors have been described for L. pneumophila such as surface proteins, secreted factors and putative virulence factors. L. pneumophila can be identified by using cultural, serologic and various molecular techniques such as DNA sequencing and DNA-DNA hybridization. Diagnosis can be made by culture, direct fluorescent antibody staining, serological tests, urinary antigen detection or nucleic acid detection and various subtyping techniques. In order to eradicate L. pneumophila from contaminated water systems several methods are available; Thermal or chemical shock \disinfection, UV irradiation, ozone treatment, silver-copper ionization, anodic oxidation and chlorine dioxide application.Öğe A new 5,6-dihydro-2-pyrone derivative from Phomopsis amygdali, an endophytic fungus isolated from hazelnut (Corylus avellana)(Elsevier, 2014) Akay, Seref; Ekiz, Guner; Kocabas, Fatma; Hames-Kocabas, E. Esin; Korkmaz, Kemal S.; Bedir, ErdalAims of this study were to isolate endophytes from different parts of hazelnut - Corylus avellana L. to obtain bioactive secondary metabolites and search for the presence of gene region of taxadiene synthase (Ts), a key enzyme in taxol biosynthesis, on selected fungi. Fourteen fungal species were isolated and cultured for the screening studies. The cell-free fermentation broths were extracted with chloroform. The chloroform extracts were tested for cytotoxic activity by MTT method. Based on the activity results and chemical profiles, the isolate identified as Phomopsis amygdali by internal transcribed spaces (ITS) sequence analysis using ITS1 primer was selected for further studies. After large-scale fermentation and purification studies, two major compounds, one of which turned out to be a new secondary metabolite, were isolated and characterized. Structure of the new metabolite was elucidated as (S)-4-butoxy-6-((S)-1- hydroxypentyl)-5,6-dihydro-2H-pyran-2-one by the extensive use of 1D and 2D NMR, and HR-MS, whereas the known compound was identified as (-) pestalotin. Additionally, to evaluate taxol-producing potential of the selected isolate, a PCR amplification study followed by gel electrophoresis analysis was carried out revealing no Ts gene region. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.Öğe Production of organic solvent-stable alkaline protease from a marine Streptomyces strain Marac 1-4(Parlar Scientific Publications (P S P), 2007) Uzel, Atac; Hames-Kocabas, E. EsinAn alkaliphilic Streptomyces strain Marac 1-4, producing an alkaline protease, was isolated from a marine sediment sample in Izmir gulf. The protease production was performed in a medium containing seawater (SWFM) and distilled water (FM), respectively, and its activity was found to be significantly higher in SWFM than in FM (p<0.1). Amono, the 11 carbon and 8 nitrogen sources, the best enzyme activity was obtained by sucrose and peptone, respectively. The enzyme was found to be stable in the presence of various oreanic solvents with log P-o/w values between 3.1 and 5.6, and showed better activity than nonsolvent-containing control. Seawater in production medium was necessary for its better activity and stability in the presence of organic solvents.Öğe Purification and identification of secondary metabolites from marine derived Streptomyces rochei 6CM016 and their antimicrobial activities(Elsevier Science Bv, 2012) Cetinel, Semiha; Uzel, Aksoy Atac; Hames-Kocabas, E. Esin; Khan, Ikhlas A.; Bedir, ErdalÖğe Tryptamine derived amides with thiazole ring system from Thermoactinomyces strain TA66-2(John Wiley & Sons Ltd, 2008) Kolrkmaz, Cagla Akmemis; Hames-Kocabas, E. Esin; Uzel, Atac; Bedir, ErdalA moderately thermophilic actinomycete strain, which was identified as Thermoactinomyces strain TA66-2, was isolated from hot-spring water. Fermentation, followed by solvent partition and chromatographic separations, resulted in the isolation of two new and two known molecules. The structures of the new compounds were elucidated as 2-(1-Propionylaminoethyl)thiazole-4-carboxylic acid [2-(1H-indol-3-yl)ethyl]amide and 2-(1-Acetylaminoethyl)thiazole-4-carboxylic acid [2-(1H-indol-3-yl)-ethyl]amide by using spectral methods (1D-, 2D-NMR and LC-ESI-MS). Copyright (C) 2007 John Wiley & Sons, Ltd.
