Seven closely related xylanolytic, thermophilic bacilli were isolated from mud and water samples from the Gonen and Diyadin hot springs, respectively located in the Turkish provinces of Balikesir and Agri. On the basis of morphology and biochemical characteristics, one of the isolates, designated strain G2 T , was studied further. Strain G2 T is a xylanolytic, sporulating, Grampositive, rod-shaped bacterium. The isolate is a thermophilic (optimum temperature for growth, 55-60˚C), facultative anaerobe that grows on a wide range of carbon sources, including glucose, starch, xylose and mannitol. It expressed a high level of xylose isomerase activity on xylose and also on glucose. 16S rRNA gene sequence analysis showed that this isolate resembled Anoxybacillus flavithermus DSM 2641 T (>97 % similarity), but 16S-23S rDNA internally transcribed spacer polymorphism PCR showed variation between DSM 2641 T and isolate G2 T . However, it is also known that analysis of 16S rRNA gene sequences may be insufficient to distinguish between some species. In DNA-DNA hybridization, thermophilic isolate G2 T showed relatedness of 53?4 % to A. flavithermus and about 45?0 % to Anoxybacillus pushchinoensis, indicating that it is distinct at the species level. On the basis of the evidence presented, it is proposed that strain G2 T (=NCIMB 13933 T =NCCB 100040 T ) be designated as the type strain of Anoxybacillus gonensis sp. nov.It is now over a century since thermophiles were first reported (Miquel, 1888). Over the years, a number of sporeforming thermophiles have been reported, mainly in the genera Bacillus and Clostridium (Guagliardi et al., 1996).In this study, we isolated some thermophilic bacilli from the Gonen and Diyadin hot springs, respectively located in the Turkish provinces of Balikesir and Agri. On the basis of preliminary experiments, a representative strain appeared to differ from other thermophilic bacilli with respect to the utilization of xylose; it was therefore characterized further. Xylose isomerase is an intracellular enzyme that catalyses the conversion of D-xylose to D-xylulose. Its practical significance stems from its ability to isomerize D-glucose to D-fructose. Therefore, this enzyme is often referred to as glucose isomerase and is widely used in industry for the production of high-fructose corn syrup.The present paper describes the isolation, morphological, physiological and biochemical profiles and 16S rRNA sequence of this strain and the results of DNA-DNA hybridization with close relatives and proposes that it represents a novel species of the genus Anoxybacillus (Pikuta et al., 2000), Anoxybacillus gonensis sp. nov. Isolation of strainsSeven Gram-positive rods were isolated from mud and water samples from the Gonen and Diyadin hot springs. The water temperature of these hot springs is around 70 uC. After collection, mud and water samples were used immediately for enrichment in nutrient broth at 60-70 uC. Oneday-old enrichment cultures were repeatedly subcultured in 10 ml nutrient broth and streaked on ...

Two thermophilic bacilli were isolated from mud and water samples of the Ayder and Kestanbol hot springs in the provinces of Rize and Canakkale, respectively, in Turkey. Strains AB04 T and K4 T were sporulating, Gram-positive, rod-shaped bacteria. These isolates were moderately

Novel homodinuclear Cu(II) (K1), heterodinuclear Cu(II)-Mn(II) (K2) and homotrinuclear Cu(II) (K3) complexes with a novel oxime-type ligand have been prepared and their nucleolytic activities on pCYTEXP were established by neutral agarose gel electrophoresis. The analyses of the cleavage products obtained electrophoretically indicate that although the examined complexes induces very similar conformational changes on supercoiled DNA by converting supercoiled form to nicked form than linear form in a sequential manner as the complex concentration or reaction period is increased, K3 is less effective than the two others. The oxime complexes were nucleolytically active at physiological pH values but the activities of Kl or K2 were diminished by increasing the pH of the reaction mixture. In contrast, K3 makes dominantly single strand nicking by producing nicked circles on DNA at almost all the applied pH values. Metal complex induced DNA cleavage was also tested for inhibition by various radical scavengers as superoxide dismutase (SOD), azide, thiourea and potassium iodide. The antioxidants inhibited the nucleolytic acitivities of the oxime complexes but SOD afforded no protection indicating that the nucleolytic mechanism involves of copper and/or manganese complex-mediated reactive oxygen species such as hydroxyl radicals being responsible for the oxidative DNA cleavage.

Diphenolases from Anoxybacillus kestanbolensis strains K1 and K4 T , highly active against 4-methylcatechol were characterized in terms of pH-and temperature-optima, pH-and temperature-stability, kinetic parameters, and inhibition/activation behaviour towards some general polyphenol oxidase (PPO) inhibitors and metal ions. The temperature-activity optima, for Anoxybacillus kestanbolensis K1 and K4 T catecholases in the presence of 4-methylcatechol, were 80 and 70°C, respectively. Although catecholase from A. kestanbolensis K4 T lost no activity after a period of 1 h incubation at its optimum temperature, the enzyme from K1 was stimulated by keeping at 80°C. Both of the enzymes possessed pH optima at 9.5, and the pH-stability profiles showed that cathecholases from both preparations retained their activities at alkaline pH values. Both A. kestanbolensis K1 and K4 T catecholase activities were totally inhibited by addition of 0.01 mM sodium metabisulphite, ascorbic acid and L -cysteine. 1 mM Mn 2+ increased the activities of A. kestanbolensis K1 and K4 T catecholases by 6.4-and 5.3-fold, respectively. These results indicate that both A. kestanbolensis K1 and K4 T strains possess thermo-and alkalostable catecholases.

Novel homotetranuclear Cu(II) and heteronuclear Cu(II)-Mn(II) complexes with tetrathioether-tetrathiol moiety have been prepared and their DNA relaxation activities with plasmid pCYTEXP (5kb) were electrophoretically established. The cleavage products analyzed by neutral agarose gel electrophoresis indicated that the interaction of the metal complexes with supercoiled plasmid DNA yielded linear, nicked or degraded DNA. The relaxation activities of both homo- and heterotetranuclear (SK4) complexes are time- and concentration-dependent. The findings suggest that SK4 with potent nucleolytic activity is a good nuclease substitute in the presence ofcooxidant. Furthermore, the observation of induction of DNA into smaller fragments by SK4 is also significant.

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