Biomedical subjects

Nurettin Sahin

Publications and source records attributed to Nurettin Sahin.

6 recordsLinked to original sources

PubMed2025

Duganella hordei sp. nov., Duganella caerulea sp. nov., and Duganella rhizosphaerae sp. nov., isolated from barley rhizosphere.

Duganella sp. strains R1T, R57T, and R64T, isolated from barley roots in Japan, are Gram-stain-negative, motile, rod-shaped bacteria. Duganella species abundantly colonized barley roots. Strains R1T, R57T, and R64T were capable of growth at 4 °C, suggesting adaptation to colonize winter barley roots. Strains R57T and R64T formed purple colonies, indicating violacein production, while strain R1T did not. Based on 16S rRNA gene sequence similarities, strains R1T, R57T, and R64T were most closely related to D. violaceipulchra HSC-15S17T (99.10%), D. vulcania FT81WT (99.45%), and D. violaceipulchra HSC-15S17T (99.86%), respectively. Their genome sizes ranged from 7.05 to 7.38 Mbp, and their genomic G+C contents were 64.2-64.7%. The average nucleotide identity and digital DNA-DNA hybridization values between R1T and D. violaceipulchra HSC-15S17T, R57T and D. vulcania FT81WT, R64T and D. violaceipulchra HSC-15S17T were 86.0% and 33.2%, 95.7% and 67.9%, and 92.7% and 52.6%, respectively. Their fatty acids were predominantly composed of C16:0, C17:0 cyclo, and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). Based on their distinct genetic and phenotypic characteristics, and supported by chemotaxonomic analyses, we propose that strains R1T, R57T, and R64T represent novel species within the Duganella genus, for which the names Duganella hordei (type strain R1T = NBRC 115982 T = DSM 115069 T), Duganella caerulea (type strain R57T = NBRC 115983 T = DSM 115070 T), and Duganella rhizosphaerae (type strain R64T = NBRC 115984 T = DSM 115071 T) are proposed.

Hordeum↗

PubMed2005

Isolation and characterization of a diazotrophic, oxalate-oxidizing bacterium from sour grass (Oxalis pes-caprae L.).

A new type of nitrogen-fixing, oxalate-oxidizing Azospirillum sp. was isolated from the roots of Oxalis pes-caprae. Polyphasic taxonomy was performed, including auxanography using API galleries, physiological tests and 16S rRNA sequence comparison. Optimum growth occurred at 30 degrees C, pH 7.5. Growth was observed at 37 and 42 degrees C with oxalate and in the presence of 3-4% NaCl and 2% potassium oxalate. In liquid culture, the doubling time (t(d)) with oxalate was 9 h. Its closest phylogenetic neighbors, as deduced by 16S rDNA-based analysis, were Azospirillum brasilense, Azospirillum doebereinerae and Azospirillum lipoferum, with 99.5, 98.4 and 96.7% sequence similarity, respectively. The strain differed from A. brasilense by its ability to use N-acetylglucosamine, D-glucose and D-mannitol. It may be a variant strain of A. brasilense. Oxalotrophic, N2-fixing species of the genus Azospirillum may be important contributors to soil formation, soil fertility, and retention and/or cycling of elements necessary for plant growth.

Azospirillum↗

PubMed2005

Antimicrobial activity of Streptomyces species against mushroom blotch disease pathogen.

Bacterial blotch caused by Pseudomonas tolaasii is still one of the main diseases in mushroom farms. Effective treatment of the infections caused by P. tolaasii is yet to be established. The isolation and identification of three Streptomyces species that showed antimicrobial activity against P. tolaasii NCPPB 2192(T) were described. Six strains were highly active with an inhibition zone more than 20 mm in diameter. They were assigned to the known Streptomyces cluster groups as S. rochei, S. lydicus and S. antibioticus. The fermentation, preliminary extraction and isolation of bioactive components were carried out. The bioactive compound may be a beta-lactam structurally related to the penicillins.

Agaricales↗

PubMed2004

Isolation and characterization of mesophilic, oxalate-degrading Streptomyces from plant rhizosphere and forest soils.

The present work was aimed at the isolation of additional new pure cultures of oxalate-degrading Streptomyces and its preliminary characterization for further work in the field of oxalate metabolism and taxonomic studies. Mesophilic, oxalate-degrading Streptomyces were enriched and isolated from plant rhizosphere and forest soil samples. Strains were examined for cultural, morphological (spore chain morphology, spore mass colour, diffusible and melanin pigment production), physiological (antibiosis, growth in the presence of inhibitory compounds, assimilation of organic acids and enzyme substrates) and chemotaxonomic characters (cellular lipid components and diagnostic cell-wall diamino acid). The taxonomic data obtained were analysed by using the simple matching (SSM) and Jaccard (Sj) coefficients, clustering was achieved using the UPGMA algorithm. All strains were able to utilize sodium-, potassium-, calcium- and ammonium-oxalate salts. Based on the results of numerical taxonomy, isolates were grouped into five cluster groups with a > or =70% S(SM) similarity level. Streptomyces rochei was the most common of the cluster groups, with a Willcox probability of P > 0.8. Streptomyces antibioticus, S. anulatus, S. fulvissimus, S. halstedii and S. violaceusniger are newly reported as oxalate-utilizing Streptomyces.

Ecosystem↗

PubMed2002

Isolation and characterization of a new type of aerobic, oxalic acid utilizing bacteria, and proposal of Oxalicibacterium flavum gen. nov., sp. nov.

A mesophilic, aerobic oxalic acid utilizing yellow-pigmented bacterium has been isolated from litter of oxalate producing plants in the region of Izmir (Turkey). It is motile by means of 1-3 polar flagella. Optimal growth occurred between 25-30 degrees C at pH 6.9. The G+C content of DNA is 62-64 mol % (Tm). Based on its morphological and biochemical features the organism belongs to the genus Pseudomonas, but differs from all the previously described species. The taxonomic relationships among strains described as or previously tentatively assigned to the genus Pseudomonas were investigated using numerical classification, DNA base composition and DNA-DNA hybridization. 16S rDNA sequences were determined for the strain TA17. On the basis of 16S rDNA sequence comparisons, physiological and biochemical characteristics, it is proposed to classify TA17T in a new genus and species for which the name Oxalicibacterium flavum gen. nov., sp. nov. is proposed. The type strain is TA17T (= NEU98T, = LMG 21571T).

Bacteria, Aerobic↗

PubMedDate not supplied

Oxalotrophic bacteria.

Oxalic acid and its salts are widespread in nature, as they are produced by many species of plants, algae and fungi. The bacteria, which are capable of using oxalate as a sole carbon and energy source, are described as being "oxalotrophic". Oxalotrophic bacteria do not constitute a homogeneous taxonomic group, but they do constitute a well-defined physiological group. A limited number of aerobic bacteria which are able to utilize oxalate as sole carbon and energy source have been completely described. Most of them are facultative methylotrophs and/or facultative hydrogen-oxidizing chemolithoautotrophs. In this review, the current status of the taxonomy and biodiversity of oxalotrophic bacteria in various environments, and aspects of their biotechnological potential, are briefly summarized.

Bacteria↗