Metin Yıldırım

Factors affecting the adsorption of buchnericin LB, a bacteriocin produced by Lactocobacillus buchneri

Summary Buchnericin-LB adsorbs to gram-positive but not to gram-negative bacteria. The tested gram-positive bacteria were species of Lactobacillus , Pediococcus , Leuconostoc , Enterococcus , Lactococcus , Listeria , Bacillus , Staphylococcus ; gram-negative bacteria belonged to the genera Salmonella , Escherichia , Yersinia and Pseudomonas . Buchnericin-LB adsorption depended on pH but not on time and temperature. Also some anions of salts and lipoteichoic acid reduced or inhibited its adsorption. Treatment of cells and cell walls of sensitive bacteria with detergents, organic solvents or enzymes did not affect subsequent binding of buchnericin-LB. Treatment with buchnericin-LB caused sensitive cells to lose high amounts of intracellular K + ions and UV-absorbing materials and became more permeable to o-nitrophenol-β-D-galactopyranoside. Buchnericin-LB (640-2560 AU/ml) decreased the colony forming units (99%) and absorbance values of Listeria monocytogenes and Bacillus cereus . These results indicate that the mode of action of buchnericin-LB is bactericidal and its lethal effect is very rapid.

Genotype X environment interactions in potato (Solanum tuberosum L.)

Genotype X environment interactions were estimated for several traits in potato from a combined analysis of 11 genotypes grown at 3 locations for 2 years. Genotype X location X year and Genotype X location interactions were significant for the majority of the traits studied. Yield, reducing sugar content, dry matter content, leaf area, plant height and starch content should be tested over multiple locations and years in order to separate the genotype × environment interaction components from the total genotypic variance.

Inheritance of plant height, tiller number per plant, spike height and 1000-kernel weight in a 8×8 diallel cross population of bread wheat

The inheritance of plant height, tiller number per plant, spike height and 1000-kernel weight was studied using a Jinks-Hayman diallel analysis in a 8×8 wheat ( Triticum aestivum L.) cross population with the following bread wheat cultivars: Cumhuriyet (1), Kasifbey (2), Ziyabey (3), Marmara (4), Basribey (5), Malabadi (6), Yuregir (7) and Seri-82 (8). The data analysis showed that the additive variance component ( D ) was significant for plant height, spike height and 1000-kernel weight at 1% level. The F parameter which is effect of dominant and recessive genes has a positive value for all four traits studied and was significant for plant height at 1% level. Dominance variance component ( H 1 ), corrected dominance variance component ( H 2 ) and dominancy level variance component ( h 2 ) were significant for all four traits studied. The Wr-Vr graphs indicated overdominance can be inferred for tiller number number per plant, spike height and 1000-kernel weight while partial dominance could be inferred fo...

Nil Tilapyası, Oreochromis niloticus (Linnaeus, 1758) Karaciğer Dokusunda Kurşunun Neden Olduğu Oksidatif Strese Karşı Humik Maddelerin Koruyucu Etkisi

Bu arastirmada, subletal kursun (Pb) derisiminin Nil tilapyasi (Oreochromis niloticus)’nda antioksidan enzim sistemi uzerine etkilerine karsi, yeme katilan humik maddenin koruyucu etkisi incelenmistir. Bu amacla 1,5 mg/L kursun nitrat Pb(NO3)2 ortam derisimi etkisindeki baliklar, %0,2 oraninda humik madde katkisi bulunan yem ile beslenmislerdir. Kontrol grubu, humik madde (HM), Pb, ve Pb+HM grublarini iceren bu calismada 4. ve 10. gunlerde karaciger doku ornekleri alinmistir. Karaciger dokusu katalaz (CAT) ve superoksit dismutaz (SOD) enzim aktiviteleri ve lipid peroksidasyon urunu olan malondealdehit (MDA) seviyesi, kontrol grubu ile karsilastirildiginda, subletal kursun derisimi uygulanan grupta 4. ve 10. gunlerde onemli oranda arttigi belirlenmistir. Pb grubu ile HM+Pb grubu karsilastirildiginda, CAT ve SOD aktivitesinde onemli bir degisime neden olmadigi, ancak humik madde uygulamasinin karaciger dokusu lipid peroksidasyonu uzerine Pb toksisitesinin etkisini azalttigi belirlenmistir. Deneme sonuclarina gore, yeme ilave edilen %0,2 humik madde, 1,5 mg/L Pb ortam derisiminin, O. niloticus karaciger dokusu lipid peroksidasyon uzerindeki toksisitesini belirli duzeyde azalttigi belirlenmistir.

Determination of Some Physicochemical and Microbiological Properties of Rosehip Marmalades

In this study, some physicochemical and microbiological properties and antioxidant capacity of 30 rosehip marmalades produced in Tokat province by industrial or regional methods were determined. pH, water activity, viscosity, total dry content, total soluble solids, total ash, total sugar content, total ascorbic acid content and Hunter values (L*, a* and b*) were carried out to determine the physicochemical properties of samples and the means were 4.12, 0.881, 2501.6 cP, 56.12%, 56.86, 0.935%, 50.24 g/L, 173.43 mg/100g, 30.89, 10.90 and 15.11, respectively. The count of S. aureus, total and fecal coliform was not detected in any samples. The total phenolic content and TEAC were performed to investigate antioxidant capacity and the average values were 921.62 mg GAE/100 g and 66.93 µmol trolox/g.

Selection in mutant populations of wheat

Abstract Several base populations were constructed of two wheat cultivars with gamma rays and fast neutrons by selecting single plants randomly in the M2 generation grown in 1976–1977. Mass selection was applied to the base populations and the 25% highest yielding single plants were selected. The progeny rows of the selected single plants were grown as M3 and M4 generations for two years. A total of 51 mutant lines, selected at the end of progeny testing, were grown during 1979–1980 and 24 mutants were selected. The 24 mutant lines originating from Akoz and Siete Cerros were tested in a micro-yield trial in 1980–1981. Three mutant lines were found promising for yielding capacity and they were promoted to uniform yield trials.