Thermostable alkaline protease produced by an Aspergillus niger strain
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A thermostable alkaline protease was isolated from the Aspergillus niger Z1 strain in a liquid Czapek Dox medium, containing casein (1% w/v) as the sole nitrogen source. Enzyme extract was subjected to electrophoresis in SDS-polyacrylamide gel. Two protein bands were seen on polyacrylamide gel. Active enzyme was visualized in a zymogram and protease activity exhibited a molecular mass of 68 kDa on SDS-polyacrylamide gel. The optimum pH for activity was found to be 9.0. The temperature optima of the enzyme was found to be 40 °C at pH 9.0 and it remained stable up to 90 °C, with 48.4% of the original activity retained after heat treatment at 90 °C for 15 min. Proteolytic activity was inhibited by PMSF, but slightly inhibited by SDS.
Some properties of crude carboxymethyl cellulase of Aspergillus niger Z10 wild-type strain
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A carboxymethyl cellulase enzyme was prepared from a wild type strain of Aspergillus niger Z10. Analyses of the enzyme preparation by SDS-PAGE revealed two protein bands showing cellulolytic activity. The molecular weight of these bands was estimated to be around 83,000 and 50,000. The optimum temperature of the enzyme was observed to be around 40 °C. It was found that the enzyme's activity has a broad pH range between 3 to 9 and 41.2% of the original activity was retained after heat treatment at 90 °C for 15 min.
Detection of polycyclic aromatic hydrocarbon (PAH) degradation genes in polluted soil by DNA extraction and colony hybridization
Coral, Gökhan | Coral, Mutlu Nisa Ünaldı
The aim of this study is to detect the DNA sequences for the PAH-dioxygenase gene, the key enzyme of the aeго-bic catabolic for polycyclic aromatic hydrocarbon degra-dation, in soil microorganisms by using extraction of total DNA, PCR amplification PAH-dioxygenase sequences, and detection with colony hybridization. To determine whether bacteria containing PAH-dioxygenase gene actually exist in environments contaminated by crude oil or not, the ge-nomic DNA was purified using a genomic DNA purifica-tion kit. Purified genomic DNA was then amplified with a thermal cycler, and the PCR products were separeted by agarose gel electrophoresis. Pseudomonas sp. strain ARP 26, which is capable of degrading phenanthrene, was used as target for colony hybridization. It was confirmed that Pseudomonas sp...
A preliminary study on tellurite resistance in Pseudomonas spp. isolated from hospital sewage
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A total of 48 Pseudomonas spp., isolated from the Çukurova University Balcalı Hospital sewage in Adana, were characterized on the basis of morphological, cultural and biochemical characteristics. To improve our understanding of the ecology of tellurite resistance in bacteria, the minimum inhibition concentrations (MIC) of potassium tellurite (K2 TeO3 ) for growth were used to determine metal tolerance of the isolated strains. Most of the strains tolerated to 55 µgr/ml potassium tellurite. Ostrain Ps 37 tolerated relatively high concentrations of tellurite (80 µgr/ml). 27% of the strains possessed plasmid mediated tellurite resistance (Telr ).
Plasmid mediated heavy metal resistances in Enterobacter spp. isolated from Sofulu landfill, in Adana, Turkey
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A total of 15 Enterobacter spp. were isolated from water drainage near the landfill in Sofulu village in Adana and were characterised on the basis of morphological, cultural and biochemical characteristics. The Maximum Tolerable Concentrations of cadmium, copper, chromium and nickel for growth were used to determine metal tolerance of the isolated strains. Among the resistant strains used in this study, Ent-5, Ent-7 and Ent-15 were found to have plasmid resistance to copper and nickel. One resistant strain, Ent-5, functioned as a donor of copper resistance. Copper resistance transferred from Ent-5 to Escherichia coli AB3505 at a frequency of approximetely 2.7 x 10-5 per recipient cell. Transformant strain had one plasmid with the same molecular weight donor strain’s plasmid. These isolates...
Separation of megabased-sized DNA molecules of Aspergillus niger using pulsed field gel electrophoresis
Coral, Gökhan | Coral, Mutlu Nisa Ünaldı
In this study, the chromosomal DNAs were extracted from Aspergillus niger Z10 wild type strain and these DNAs were separated using the contour clamped homogeneous electric field gel electrophoresis (CHEF) system. This system is laboratory-made and is operated by a computer program. Total DNAs resolved into five distinct chromosomal bands. The size of the chromosomes was estimated as being between 3.3 Mb to 6.4 Mb.
Some properties of thermostable xylanase from an Aspergillus niger strain
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A thermostable xylanase was isolated from an Aspergillus niger wild type strain in a liquid Czapek Dox medium, containing oat spelts xylan as the sole carbon source. The molecular mass of the enzyme was estimated to be about 36 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimum pH for activity was found to be 7.5. The temperature optimum of the enzyme was found to be 60 °C at pH 7.5. The enzyme remained stable up to 100 °C, yet lost about 50% of its activity after 15 min at this temperature.
Keratinolytic activity of Streptomyces strain BA7, a new isolate from Turkey
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A wild type Streptomyces strain BA7 which was isolated from soil, showed a high keratinolytic activity when cultured on native feather medium. Optimum keratinolytic activity was observed at 50 ºC and pH 8.5 when using fluid supernatant obtained from aerated culture of this organism. The keratinolytic activity was completely stable (100%) between 30 and 60 ºC. The molecular weight of crude enzyme was estimated by SDS-PAGE about 44000 Da. The degradation of intact feathers by Streptomyces sp. BA7 keratinase was obtained after 24 h of incubation at 50 ºC. Keratinolytic activity was partially inhibited by 1,10-phenanthroline, but slightly inhibited by CaCl2, ZnCl2, and SDS. In addition keratinolytic activity was enhanced by DMSO, EDTA, Triton-X 100 and sodium sulphite. Streptomyces strain BA7 ...
Plasmid-Encoded Heavy Metal Resistance in Pseudomonas sp.
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
No abstract available
Enzymatic properties of a novel thermostable, thermophilic, alkaline and chelator resistant amylase from an alkaliphilic Bacillus sp. isolate ANT-6
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A thermostable alkaline α-amylase producing Bacillus sp. ANT-6 was isolated from soil samples. Enzyme synthesis occurred at temperatures between 25 and 45 °C with an optimum of 37 °C. There was a slight variation in amylase synthesis within the pH range 7 and 11 with an optimum pH of 9. The optimum temperatures for amylase production and growth were the same. Analyses of the enzyme by sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed a single band, which show amylolytic activity, detected in starch gel. The relative molecular mass of the partial purified enzyme was estimated to be 94 500 Da. The enzyme showed optimum activity at pH 10.5 and 80 °C. The partial purified enzyme was highly active in the alkaline range of pH (9.5–13), and it was completely active up to 100 °C ...