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Biology

Journal

2012

Characterization

Articles 1 - 3 of 3

Full-Text Articles in Life Sciences

Purification And Characterization Of Endoxylanase Xln-2 From Aspergillus Niger B03, Georgi Dobrev, Boriana Zhekova Jan 2012

Purification And Characterization Of Endoxylanase Xln-2 From Aspergillus Niger B03, Georgi Dobrev, Boriana Zhekova

Turkish Journal of Biology

An extracellular multiple form of endoxylanase was isolated from the xylanolytic complex of Aspergillus niger B03. The enzyme was purified to a homogenous form using ultrafiltration, anion exchange chromatography, and gel filtration. It was a nonglycosylated protein with a molecular weight of 20,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and 21,000 Da as determined by gel filtration. The optimal pH for the enzyme action was 5.0 and the optimal temperature was 55 °C. Endoxylanase stability was significantly improved in the presence of glycerol and sorbitol. The enzyme activity was activated by Mn^{2+} and Co^{2+}, and it was …


Cloning And Sequencing Of Coat Protein Gene Of Zucchini Yellow Mosaic Virus Isolated From Squash And Muskmelon In Turkey, Meryem Özer, Hi̇kmet Murat Si̇pahi̇oğlu, Mustafa Usta, Hakan Fi̇dan Jan 2012

Cloning And Sequencing Of Coat Protein Gene Of Zucchini Yellow Mosaic Virus Isolated From Squash And Muskmelon In Turkey, Meryem Özer, Hi̇kmet Murat Si̇pahi̇oğlu, Mustafa Usta, Hakan Fi̇dan

Turkish Journal of Biology

The coat protein (CP) genes of the genomic RNA of 2 severe Turkish isolates of Zucchini yellow mosaic virus (ZYMV) from squash and muskmelon [ZYMV-Adana (Ad) and ZYMV-Ahlat (Ah), respectively] were cloned, and their complete nucleotide sequences and deduced amino acids were determined. The analysis revealed that both Turkish ZYMV-CP genes contained 837 nucleotides encoded for a CP of about 31.2 kDa. Phylogenetic trees based on nucleic acid sequences were constructed by the neighbor joining and unweighted pair group mean arithmetic (UPGMA) methods with 100 bootstrap replicates. A high degree of homology was detected between the 2 Turkish isolates on …


Purification And Properties Of An Endoglucanase From Aspergillus Niger Vtcc-F021, Thi Hoa Pham, Dinh Thi Quyen, Ngoc Minh Nghiem Jan 2012

Purification And Properties Of An Endoglucanase From Aspergillus Niger Vtcc-F021, Thi Hoa Pham, Dinh Thi Quyen, Ngoc Minh Nghiem

Turkish Journal of Biology

An extracellular endoglucanase (EG) from Aspergillus niger VTCC-F021 was purified 2.09-fold to homogeneity with a yield of 18.4%. The enzyme had a molecular mass of 31 kDa and a specific activity of 14.122 U/mg protein. Optimum temperature was observed at 55 °C and optimum pH at 5. The enzyme was stable up to 50 °C and from pH 5 to 6 with residual activity >80% and 60%, respectively. The kinetic constants K_m and V_{max} determined for EG, with carboxyl methyl cellulose as a substrate, were 8.5815 mg CMC/mL and 20.121 U/mg protein, respectively. EDTA increased EG activity by 35% at …