No abstract

Previously isolated 115 endospore-forming bacilli were basically grouped according to their temperature requirements for growth: the thermophiles (74%), the facultative thermophiles (14%) and the mesophiles (12%). These isolates were taken into 16S rRNA gene sequence analyses, and they were clustered among the 7 genera: Anoxybacillus, Aeribacillus, Bacillus, Brevibacillus, Geobacillus, Paenibacillus, and Thermoactinomycetes. Of these bacilli, only the thirty two isolates belonging to genera Bacillus (16), Brevibacillus (13), Paenibacillus (1) and Thermoactinomycetes (2) were selected and presented in this paper. The comparative sequence analyses revealed that the similarity values were ranged as 91.4-100 %, 91.8- 99.2 %, 92.6- 99.8 % and 90.7 - 99.8 % between the isolates and the related type strains from these four genera, respectively. Twenty nine of them were found to be related with the validly published type strains. The most abundant species was B. thermoruber with 9 isolates followed by B. pumilus (6), B. lichenformis (3), B. subtilis (3), B. agri (3), B. smithii (2), T. vulgaris (2) and finally P. barengoltzii (1). In addition, isolates of A391a, B51a and D295 were proposed as novel species as their 16S rRNA gene sequences displayed similarities ≤ 97% to their closely related type strains. The AluI-, HaeIII- and TaqI-ARDRA results were in congruence with the 16S rRNA gene sequence analyses. The ARDRA results allowed us to differentiate these isolates, and their discriminative restriction fragments were able to be determined. Some of their phenotypic characters and their amylase, chitinase and protease production were also studied and biotechnologically valuable enzyme producing isolates were introduced in order to use in further studies

A novel moderately thermophilic, Gram-positive staining, rod-shaped, spore-forming, motile, facultative anaerobic, and α-glucosidase producing strain A343(T), was isolated from a high temperature well-pipeline sediment sample in Salavatli province of Aydin, Turkey. Growth was observed at 37-69 ºC (optimum 60 °C), at pH 5.5-9.5 (optimum 8.0-9.0) and at salinities from 0 to 4.5% (w/v) (optimum 2%). Strain A343(T) was able to grow on a wide range of carbon sources. Gelatin and starch utilization, amylase, catalase and oxidase activities, reduction of nitrate to nitrite were all positive. The G+C content of the genomic DNA was 45.1 mol%. The major menaquinone was MK-7. The dominant cellular fatty acids were: iso-C15:0, C16:0, and iso-C17:0. The phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain A343(T) belonged to the genus Anoxybacillus. The 16S rRNA gene sequence similarity between strain A343(T) and the type strains of recognized Anoxybacillus species was ranged from 95.8 to 99.4%. DNA-DNA hybridization revealed low homology with its closest relative Anoxybacillus kamchatkensis (49.7%). In addition to the total cell protein profiles, the Rep-PCR and the intergenic 16S-23S rRNA gene fingerprinting profiles differentiated strain A343(T) from all of the reference Anoxybacillus species used. Based upon phenotypic, phylogenetic and chemotaxonomic evidence, strain A343(T) was assigned to a new species within the genus Anoxybacillus, A. salavatliensis sp. nov. (The type strain A343(T) = DSM 22626(T) = NCIMB 14579(T)). The 16S rRNA gene nucleotide sequence of strain A343(T) is available in the GenBank database under the accession number--EU326496. Weinheim).

No abstract

We have partially purified and characterized two new thermostable exo-a-1,4-glucosidases (E.C.3.2.1.20) isolated from Geobacillus sp. A333 and thermophilic bacterium A343 strains. A333 a-glucosidase showed optimum activity at 60°C, pH 6.8 and had a value of 1.38 K m for the pNPG substrate, whereas these results were found to be 65°C, 7.0 and 0.85, respectively for A343 enzyme. Specificity for 20 different substrates and thin layer chromatography studies demonstrated that the A333 enzyme had high transglycosylation activity, and A343 had wide substrate specificity. The substrate specificity of A333 a-glucosidase was determined as maltose, dextrin, turanose, maltotriose, maltopentaose, meltotetraose, maltohexaose and phenyla-D-glycopyranoside. On the other hand, the A343 a-glucosidase mostly hydrolyzed dextrin, turanose, maltose, phenyl-a-D-glucopyranoside, maltotriose, maltotetraose, maltopentaose, isomaltose, saccharose and kojibiose by acting a-1,2, a-1,3, a-1,4 and a-1,6 bonds of these substrates. The relative activites of A333 and A343 enzymes were determined to be 83 and 92% when incubated at 60°C for 5 h whereas, the pH of 50% inactivation at 60°C for 15 h were determined to be pH 4.5/10.0 and pH 5.0/10.0, respectively. In addition, the results not only showed that both of the a-glucosidases were stable in a wide range of pH and temperatures, but were also found to be resistant to most of the denaturing agents, inhibitors and metal ions tested. With this study, thermostable exo-a-1,4-glucosidases produced by two new thermophilic strains were characterized as having biotechnological potential in transglycosylation reactions and starch hydrolysis processes.

The phylogenetic diversity of 31 thermophilic bacilli belonging to genera Geobacillus and Aeribacillus were investigated which were isolated from various geothermal sites of Turkey. Twenty-seven of these isolates were found to be belonged within the genus Geobacillus, whereas 4 of them were identified as Aeribacillus pallidus. The comparative 16S rRNA gene sequence analyses revealed that the A. pallidus isolates displayed sequence similarity values from 98.0 to 99.6% to their closest relative. Furthermore, Geobacillus isolates showed sequence similarity values from 88.9 to 99.8% with the reference type strains. According to the phylogenetic analysis, isolates belonging to genus Geobacillus were diverged into Moreover, the sequence comparisons of E173a, E265, C161ab and A142 isolates demonstrated that they represented novel species among genus Geobacillus as they shared lower than 96.7% sequence similarity to all the described type species. The AluI-, HaeIII-and TaqI-AR-DRA results were in congruence with the 16S rRNA gene sequence analyses. By ARDRA results, the isolates were able to be differentiated and clustered, the discriminative restriction fragments of these isolates and type species were determined and the novelty of E173, E265, C161ab and A142 isolates could be displayed. Some differentiating phenotypic characters and the ability of amylase, glucosidase and protease production of these bacilli were also studied and biotechnologically valuable thermostable enzyme producing isolates were introduced in order to use in further studies.

In this study, the dual-hyperbolic Fibonacci and dual-hyperbolic Lucas numbers are introduced. Then, the fundamental identities are proven for these numbers. Additionally, we give the identities regarding negadual-hyperbolic Fibonacci and negadual-hyperbolic Lucas numbers. Finally, Binet formulas, D’Ocagne, Catalan and Cassini identities are obtained for dual-hyperbolic Fibonacci and dual-hyperbolic Lucas numbers.

No abstract