Demet Cetin

Gold-Coated Iron Composite Nanospheres Targeted the Detection of Escherichia coli

We report the preparation and characterization of spherical core-shell structured Fe3O4–Au magnetic nanoparticles, modified with two component self-assembled monolayers (SAMs) consisting of 3–mercaptophenylboronic acid (3–MBA) and 1–decanethiol (1–DT). The rapid and room temperature synthesis of magnetic nanoparticles was achieved using the hydroxylamine reduction of HAuCl4 on the surface of ethylenediaminetetraacetic acid (EDTA)-immobilized iron (magnetite Fe3O4) nanoparticles in the presence of an aqueous solution of hexadecyltrimetylammonium bromide (CTAB) as a dispersant. The reduction of gold on the surface of Fe3O4 nanoparticles exhibits a uniform, highly stable, and narrow particle size distribution of Fe3O4–Au nanoparticles with an average diameter of 9 ± 2 nm. The saturation magnetization value for the resulting nanoparticles was found to be 15 emu/g at 298 K. Subsequent surface modification with SAMs against glucoside moieties on the surface of bacteria provided effective magnetic separation. Comparison of the bacteria capturing efficiency, by means of different molecular recognition agents 3–MBA, 1–DT and the mixed monolayer of 3–MBA and 1–DT was presented. The best capturing efficiency of E. coli was achieved with the mixed monolayer of 3–MBA and 1–DT-modified nanoparticles. Molecular specificity and selectivity were also demonstrated by comparing the surface-enhanced Raman scattering (SERS) spectrum of E. coli-nanoparticle conjugates with bacterial growth media.

Amycolatopsis cihanbeyliensis sp. nov., a halotolerant actinomycete isolated from a salt mine.

A novel halotolerant actinomycete, designated strain BNT52(T), was isolated from soil collected from Cihanbeyli Salt Mine in the central Anatolia region of Turkey, and examined using a polyphasic taxonomic approach. The isolate was found to have chemical and morphological properties typical of the genus Amycolatopsis and formed a distinct phyletic line in the 16S rRNA gene tree. Strain BNT52(T) was most closely related to Amycolatopsis nigrescens CSC17Ta-90(T) (96.7 %), Amycolatopsis magusensis KT2025(T) (96.6 %), Amycolatopsis sulphurea DSM 46092(T) (96.6 %), Amycolatopsis dongchuanensis YIM 75904(T) (96.5 %), Amycolatopsis ultiminotia RP-AC36(T) (96.4 %) and Amycolatopsis sacchari DSM 44468(T) (96.4 %). Sequence similarities with other strains of species of the genus Amycolatopsis were lower than 96.2 %. The isolate grew at 20-37 °C, pH 6-12 and in the presence of 0-10 % (w/v) NaCl. The cell wall of the novel strain contained meso-diaminopimelic acid and arabinose and galactose as the diagnostic sugars. Major fatty acids were iso-C16 : 0 2-OH and iso-C16 : 0. The predominant menaquinone was MK-9(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylmethylethanolamine. The genomic DNA G+C content was 68.8 mol%. On the basis of the data from this polyphasic taxonomic study, strain BNT52(T) represents a novel species within the genus Amycolatopsis for which the name Amycolatopsis cihanbeyliensis sp. nov. is proposed (type strain BNT52(T) = KCTC 29065(T) = NRRL B-24886(T) = DSM 45679(T)).

Saccharomonospora amisosensis sp. nov., isolated from deep marine sediment

A novel actinomycete, strain DS3030(T), was isolated from a deep sediment sample, collected from the southern Black Sea coast, Turkey, and was examined using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain DS3030(T) was shown to belong to the genus Saccharomonospora and to be related most closely to Saccharomonospora marina XMU15(T) (99.6 % similarity). Sequence similarities with other strains of the genus Saccharomonospora were lower than 97.0 %. The organism had chemical and morphological features typical of the genus Saccharomonospora. The cell wall of the novel strain contained meso-diaminopimelic acid, arabinose and galactose as diagnostic sugars. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The predominant menaquinone was MK-9(H4). Major fatty acids were iso-C16 : 0, iso-C16 : 0 2-OH and C16 : 1cis 9. Phenotypic data clearly distinguished the new isolate from its closest relative, S. marina XMU15(T). The combined genotypic and phenotypic data and low DNA-DNA relatedness with its closest related strain reveal that strain DS3030(T) represents a novel species of the genus, for which the name Saccharomonospora amisosensis sp. nov. is proposed. The type strain is DS3030(T) ( = DSM 45685(T) = KCTC 29069(T) = NRRL B-24885(T)).

Nonomuraea jabiensis sp. nov., isolated from arid soil

A novel actinomycete, strain A4036(T), was isolated from a soil sample collected from the Jabi district in Abuja, Nigeria. The taxonomic position of strain A4036(T) was established using a combination of genotypic and phenotypic analyses. The organism formed extensively branched substrate and aerial hyphae that generated spiral chains of spores with warty surfaces. The cell wall contained meso-diaminopimelic acid and the cell-wall sugars were glucose, madurose, mannose and ribose. The predominant menaquinone was MK-9(H(4)). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylmethylethanolamine, phosphatidylinositol mannoside, hydroxy-phosphatidylethanolamine, hydroxy-phosphatidylmethylethanolamine, two unidentified phospholipids and four unknown glucosamine-containing phospholipids. The major cellular fatty acids were iso-C(16 : 0) 2-OH, iso-C(16 : 0) and 10-methyl C(17 : 0). On the basis of 16S rRNA gene sequence similarity studies, strain A4036(T) grouped in the genus Nonomuraea, being most closely related to Nonomuraea angiospora IFO 13155(T) (99.05 %), Nonomuraea candida HMC10(T) (98.78 %), Nonomuraea kuesteri GW 14-1925(T) (98.49 %), Nonomuraea endophytica YIM 65601(T) (98.42 %), Nonomuraea maheshkhaliensis 16-5-14(T) (98.40 %), Nonomuraea turkmeniaca DSM 43926(T) (98.38 %), Nonomuraea helvata IFO 14681(T) (98.29 %), Nonomuraea rubra DSM 43768(T) (98.10 %) and Nonomuraea salmonea DSM 43678(T) (98.06 %). Levels of 16S rRNA gene sequence similarity to the type strains of other species of the genus Nonomuraea were <98 %. Despite the high 16S rRNA gene sequence similarities, DNA-DNA relatedness values and phenotypic data demonstrated that strain A4036(T) was clearly distinguished from all closely related species of the genus Nonomuraea. Thus, this isolate is considered to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea jabiensis sp. nov. is proposed. The type strain is A4036(T) (= DSM 45507(T) = KCTC 19870(T)).

Streptosporangium anatoliense sp. nov., isolated from soil in Turkey

A novel actinobacterium, strain N9999T, was isolated from soil and its taxonomic position determined using a polyphasic approach. The organism formed abundant aerial hyphae that differentiated into spherical spore vesicles. The cell wall contained meso-diaminopimelic acid; the whole-cell sugars were galactose, glucose, mannose, madurose and ribose; the predominant menaquinones MK-9 (H2) and MK-9 (H4); the major phospholipids phosphatidylethanolamine, diphosphatidylglycerol, a phosphaglycolipid and phosphatidylinositol mannosides; while the cellular fatty acids were rich in iso-C14:0, C15:0, cis-9-C17:1, iso-C16:0 and 10-methyl C17:0 components. Phylogenetic analyses based on an almost complete 16S rRNA gene sequence indicated that strain N9999T was closely related to a group that consisted of Streptosporangiumpseudovulgare DSM 43181T and Streptosporangium nondiastaticum DSM 43848T. However, DNA–DNA relatedness and phenotypic data demonstrated that strain N9999T was clearly distinguished from all closely related Streptosporangium species. The combined genotypic and phenotypic data demonstrate conclusively that the isolate should be classified as a new species of Streptosporangium.

Pseudonocardia cypriaca sp. nov., Pseudonocardia salamisensis sp. nov., Pseudonocardia hierapolitana sp. nov. and Pseudonocardia kujensis sp. nov., isolated from soil.

The taxonomic positions of four novel actinomycetes isolated from soil samples, designated KT2142T, PM2084T, K236T and A4038T, were established by using a polyphasic approach. The organisms had chemical and morphological features that were consistent with their classification in the genus Pseudonocardia. Whole-cell hydrolysates of the four strains contained meso-diaminopimelic acid and arabinose and galactose as the diagnostic sugars (cell-wall type IV). Their predominant menaquinone was found to be MK-8(H4). The major fatty acid was iso-C16:0. 16S rRNA gene sequence data supported the classification of the isolates in the genus Pseudonocardia and showed that they formed four distinct branches within the genus. DNA-DNA relatedness studies between the isolates and their phylogenetic neighbours showed that they belonged to distinct genomic species. The four isolates were readily distinguished from one another and from the type strains of species classified in the genus Pseudonocardia based on a combination of phenotypic and genotypic properties. In conclusion, it is proposed that the four isolates be classified in four novel species of the genus Pseudonocardia, for which the names Pseudonocardia cypriaca sp. nov. (type strain KT2142T=KCTC 29067T=DSM 45511T=NRRL B-24882T), Pseudonocardia hierapolitana sp. nov. (type strain PM2084T=KCTC 29068T=DSM 45671T=NRRL B-24879T), Pseudonocardia salamisensis sp. nov. (type strain K236T=KCTC 29100T=DSM 45717T) and Pseudonocardia kujensis sp. nov. (type strain A4038T=KCTC 29062T=DSM 45670T=NRRL B-24890T) are proposed.

Streptomyces karpasiensis sp. nov., isolated from soil

A novel actinobacteria, designated strain K413(T), was isolated from soil collected from Karpaz National Park, Magusa, Northern Cyprus, and characterized to determine its taxonomic position. The isolate was found to have chemical and morphological properties associated with members of the genus Streptomyces. Phylogenetic analyses based on almost-complete 16S rRNA gene sequences indicated that the isolate was closely related to members of the genus Streptomyces, and was shown to form a distinct phyletic line in the Streptomyces phylogenetic tree. Strain K413(T) was most closely related to Streptomyces marinus DSM 41968(T) (98.01%). Sequence similarities with other strains of the genus Streptomyces were below 98.0%. The cell wall of the novel strain contained ll-diaminopimelic acid. The predominant menaquinone was MK-9(H8) (45.0%). The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine and phosphatidylinositol. The major fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. Based on 16S rRNA gene sequence analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data, strain K413(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces karpasiensis sp. nov. is proposed. The type strain is K413(T) ( = KCTC 29096(T) = DSM 42068(T)).

Streptomyces burgazadensis sp. nov., isolated from soil

A novel actinobacterial strain, designated Z1R7(T), was isolated from a soil sample collected from Burgazada, in the Marmara Sea (Turkey), and the strain identity was determined using a polyphasic taxonomic approach. The organism had chemotaxonomic and morphological properties consistent with its classification in the genus Streptomyces and it formed a distinct phyletic line in the 16S rRNA gene tree, together with the type strains Streptomyces specialis GW41-1564(T) (95.76 %), Streptomyces mayteni YIM 60475(T) (95.64 %), Streptomyces hainanensis YIM 47672(T) (95.53 %), Streptomyces hoynatensis S1412(T) (95.29 %), Streptomyces avicenniae MCCC 1A01535(T) (94.74 %), Streptomyces sedi YIM 65188(T) (94.59 %) and Streptomyces zhaozhouensis NEAU-LZS-5(T) (94.68 %). Chomotaxonomic data revealed that strain Z1R7(T) possesed MK-9 (H8) as the predominant menaquinone, ll-diaminopimelic acid as the diagnostic diamino acid, and galactose, glucose and ribose as whole cell sugars. Diphosphatidylglycerol, phoshphatidylethanolamine and phosphatidylinositol were the predominant polar lipids; iso-C16 : 0, anteiso-C17 : 0 and anteiso-C15 : 0 were the major fatty acids, and the genomic DNA G+C content was 69.4 mol%. On the basis of these genotypic and phenotypic data, it is proposed that isolate Z1R7(T) ( = KCTC 29434(T) = DSM 42126(T)) should be classified in the genus Streptomyces as Streptomyces burgazadensis sp. nov.

Nanoparticle embedded chitosan film for agglomeration free TEM images

Transmission electron microscopy (TEM) is a very useful and commonly used microscopy technique, used especially for the characterization of nanoparticles. However, the identification of the magnetic nanoparticle could be thought problematic in TEM analysis, due to the fact that the magnetic nanoparticles are usually form aggregates on the TEM grid to form bigger particles generating higher stability. This prevents to see exact shape and size of each nanoparticle. In order to overcome this problem, a simple process for the formation of well‐dispersed nanoparticles was conducted, by covering chitosan film on the unmodified copper grid, it was said to result in aggregation‐free TEM images. It is also important to fix the magnetic nanoparticles on the TEM grids, due to possible contamination of TEM filament which is operated under high vacuum conditions. The chitosan film matrix also helps to protect the TEM filament from contact with magnetic nanoparticles during the imaging process. The proposed procedure offers a quick method to fix the nanoparticles in a conventional copper TEM grid and chitosan matrix prevents agglomeration of nanoparticles, and thus getting TEM images showing well‐dispersed individual nanoparticles.

Lechevalieria nigeriaca sp. nov., isolated from arid soil.

A novel actinobacterium, designated strain NJ2035(T), was isolated from soil collected from Abuja, Nigeria and was characterized to determine its taxonomic position. The isolate was found to have chemical and morphological properties associated with members of the genus Lechevalieria. Phylogenetic analyses based on almost-complete 16S rRNA gene sequences indicated that the isolate was closely related to members of the genus Lechevalieria, and was shown to form a distinct phyletic line in the Lechevalieria phylogenetic tree. Strain NJ2035(T) was most closely related to Lechevalieria roselyniae C81(T), Lechevalieria atacamensis C61(T) and Lechevalieria deserti C68(T) (98.5 % 16S rRNA gene sequence similarity). Sequence similarities with other members of the genus Lechevalieria were less than 98.2 %. The cell wall of the novel strain contained meso-diaminopimelic acid, and galactose, mannose and rhamnose as the diagnostic sugars. The predominant menaquinone was MK-9(H4). The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. DNA-DNA relatedness and phenotypic data showed that the novel isolate and L. roselyniae C81(T), L. atacamensis C61(T) and L. deserti C68(T) belong to distinct genomic species. On the basis of data from this taxonomic study using a polyphasic approach, strain NJ2035(T) represents a novel species of the genus Lechevalieria, for which the name Lechevalieria nigeriaca sp. nov. is proposed. The type strain is NJ2035(T) ( = DSM 45680(T) = KCTC 29057(T) = NRRL B-24881(T)).