Electrofusion of Saccharomyces cerevisiae Auxotrophic Mutants of Identical Mating Type Using a Laboratory-Made System
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
Yeast protoplasts from haploid auxotroph strains DC6 (MATα) and FY73 (MATα) were exposed to an inhomogeneous alternating field (AC 200 V/cm). Due to the dielectrophoretic aggregation two or more cells with close membrane contact were formed between the two electrodes. The effects of different DC pulses were investigated to determine critical fusogenic pulse strength. In the results, the maximum fusant cells were obtained only when 8 kV field strengths were applied. These findings showed that the optimum fusogenic pulse strength for yeast protoplasts is 8 kV/cm under our experimental conditions. After fusion, the DNA contents of both hybrid and individual parental strains were compared. The amount of DNA in the hybrid was found to be about twofold higher than that in the individual parental...
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.
Apparent Nutrient Digestibility of Balanced Diets with Soy Bean Extract or Meat and Bone Meal in the Nile Tilapia (Oreochromis niloticus L.) Infected with Vibrio anguillarum
ENGİN, KENAN | YILMAZ, FERBAL ÖZKAN
Nile tilapia, Oreochromis niloticus L., infected with Vibrio anguillarum or not infected were fed balanced diets containing vegetal (solvent extracted soy bean meal (SBM)) or animal (meat and bone meal (MBM)) protein sources in order to demonstrate the apparent nutrient and energy digestibility. Regardless of protein sources in the diets, feed intake was lower in the infected group. Apparent nutrient (AD_{DM} and AD_{CP}) and energy digestibility (AD_{kJ}) values of Nile tilapia fed the SBM diet were significantly better (P < 0.05) than those fed the CONT and MBM diets and changed little between the measurement days in both groups (non-infected and infected). Although no visible symptoms associated with vibriosis were evident on either the skin or internal organs, the significantly lower (...
Induction of micronuclei and other nuclear abnormalities in peripheral erythrocytes of Nile tilapia, Oreochromis niloticus, following exposure to sublethal cadmium doses
YILMAZ, FERBAL ÖZKAN | HUNT, ARZU ÖZLÜER
The genotoxic effects of sublethal doses of cadmium in peripheral erythrocytes of Oreochromis niloticus was investigated using micronucleus (MN) and nuclear abnormalities (NAs) tests. For this reason, the fish were exposed to medium changes of 0.5 and 1.0 mg/L doses of cadmium (Cd) during an average treatment period of 10 days. On the 2nd, 4th, 6th, and 10th days of the test period, the erythrocytes, including the micronuclei (MN) and other nuclear abnormalities such as lobbed nuclei (LB), blebbed nuclei (BL), and notched nuclei (NT), were counted and pointed out. As a positive control, a 4 mg/L dose of cyclophosphamide was used. Exposure to doses of cadmium caused significantly increased (P < 0.05) micronuclei in peripheral erythrocytes of fish. It was also observed that the application o...
Photochemical Bromination of Substitued Indan 1 one Derivatives Synthesis of New Polybromoindan 1 one Derivatives
Nermin, Şimşek Kuş
he photobromination of substituted indan derivatives was studied. Four products, 2,3-dibromo-inden1-one (5), trans-2,3-dibromoindan-1-one (6), 2,2-dibromoindan-1,3-dione (7) and 2,2-dibromoindan-1-one (8), were obtained by the bromination of indan-1-one (4). The bromination of 2-methyl indanone (9) and 3- methyl-indanone (13) gave the corresponding monobromo, dibromo, and tribromo compounds in high yield. 4-Nitro indan (16) was tribrominated under same condition reaction. The structures of these products were determined from 1 H-NMR, 13 C-NMR, MS, and IR data.
Seasonal variation of Hysterothylacium aduncum Nematoda Raphidascarididae infestation in sparid fishes in the Northeast Mediterranean Sea
Kalay Mustafa | Dönmez Ahmet Erdem | Koyuncu Cafer Erkin
The presence of a Raphidascarid parasitic nematode Hysterothylacium aduncum (Rudolphi, 1802) in the sparid fish Sparus aurata and Diplodus vulgaris was investigated in this study. A total of 471 individuals (208 Sparus aurata and 263 Diplodus vulgaris) collected for this purpose from the Gulf of Mersin between May 2003 and April 2004 were examined. Seasonal variation in the intensity (MI: mean ± SD) and prevalence (P: %) of the parasite were also determined and the highest P and MI values were found in June 2003 (3.5 ± 0.71 and 8.70%) for S. aurata and March 2004 (4.0 ± 0 and 19.5%) for D. vulgaris.