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Mastitis is one of the most considerable and costly diseases for dairy herds, and Staphylococcus spp. is known to be the main causative agent. Although antibiotics are widely used in the treatment of mastitis, this can cause both antibiotic residues in milk and the risk of antibiotic resistance occurrence in bacteria. Thus, in recent years, researchers have focused on alternative treatments for this disease and plants extracts are investigated for this purpose. Pomegranate is widely used as a dye, ornament, and medicinal plants in the industry, and the species has a particularly high economic value in Turkey. This study aims to investigate in vitro the antioxidant and antibacterial properties of the pomegranate flower's extracts against different Staphylococcus species associated with bovine mastitis. To this aim, pomegranate flowers were collected from different regions in Turkey and extracts were prepared with three different solvents (methanol, ethanol, and water). The retention factor values of the ethanol extract were determined by thin-layer chromatography. The antibacterial activity tests were carried out via the disk diffusion method. In addition, the extracts were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radicals for antioxidant activity. Four retention factors (0.79, 0.67, 0.58, and 0.33 points) were found for the ethanol extract. The methanol extract showed the highest inhibition zones against coagulase-negative Staphylococcus-37 (CNS-37) and S. aureus-18. The lowest MIC was 6500 μg/mL. The highest antioxidant activity was observed in methanol extracts. As a result, the extracts of pomegranate flowers showed a high antioxidant and antibacterial potential against the examined mastitis pathogens.

Bu tez çalışmasında Alüminyum (Al)'a toleranslı Demir 2000 buğday (Triticum aestivum L.) genotipinin hidroponik ortamda kök boy ölçümleri, kök ve sürgünlerinde antioksidan enzim (SOD, APX, GPX) aktivitesi, prolin ve MDA içerikleri ve ortama salgılanan metabolitlerin Nükleer Manyetik Rezonans (NMR) verileri araştırılmıştır. AlCl3 uygulamalarına 1 gün süreyle maruz bırakılan buğday fidelerinin ortama salgıladıladığı metabolitler NMR tekniği yardımı ile tespit edilmiştir.Araştırma sonucunda elde edilen bulgulara göre; artan Al konsantrasyonları ile beraber bitki kök boyunda istatiksel olarak anlamlı bir değişim olmamıştır. Prolin, MDA ve GPX sonuçları bakımından, hem kök hem de sürgün dokularında uygulamalar arasında istatistiksel bir farklılık (P < 0.05) tespit edilmemiştir. Ancak her 3 parametre için de, kök dokusunda elde edilen değerler sürgün dokusuna göre anlamlı olarak yüksek çıkmıştır. SOD ve APX enzim aktivitelerinde ise hem kök hem de sürgün dokularında, uygulamalar arasında istatistiksel farklılıklar belirlenmiştir. Özellikle, artan Al konsantrasyonlarına bağlı olarak elde edilen sonuçlarda da anlamlı artışlar gözlemlenmiştir. SOD enzim aktivitesi kök dokusunda daha fazla çıkarken, APX enzim aktivitesinde dokular arasında bir farklılık tespit edilmemiştir. NMR verileri açısından kök dokusunun Al'a karşı ortama salgıladığı metabolitler [karbonhidrat (maltoz, sukroz, fruktoz), ester (O-fosfoserin), amino asit (valin, lösin, alanin) ve şeker alkolü (arabinitol, glusitol ve mannitol)] tüm kontrol ve Al uygulamalarında (0, 10µM, 30 µM, 50 µM AlCl3) bir farklılık göstermemiştir.Demir buğday (Triticum aestivum L.) 2000 genotipinin Al'lu ortamda dışarıya salgıladığı metabolitlerin Al stresine karşı bitkide bir savunma mekanizmasının vermiş olduğu cevap olarak düşünülmektedir.Anahtar Kelimeler: Buğday, Al, NMR Spektroskopisi, Sekonder Metabolitler, Antioksidatif Enzimler In this thesis, Al-tolerant Demir 2000 wheat (Triticum aestivum L.) genotype's root length measurements, antioxidant enzyme (SOD, APX, GPX) activities, Proline and MDA content in root and shoot tissues, and NMR data of secreted metabolites from the roots to the growing hydroponic medium were investigated.According to the data obtained at the end of the research; statistically, there has been no change found in plant roots lenght with increasing Al concentrations. For results of Proline, MDA and GPX, a statistical difference in both root and shoot tisues were not detected between treatments. However for all 3 parameters, the values obtained from the root tissue were significantly higher than shoot tissue. In APX and SOD enzyme activity in both root and shoot tissues, a statistical difference were determined between treatments. Especially, significant increases were observed in results obtained due to the increased Al concentrations. While SOD enzyme activity were higher in root tissue, there were no difference found between root and shoot tissues for APX enzyme activities.In terms of NMR data, secreted metabolites from root tissues (carbohydrates [maltose, sucrose, fructose], ester [O-phosphoserine], amino acids [valine, leucine, alanine] and sugar alcohol [arabinitol, glucitol and mannitol]) no differences were detected for any treatment (0, 10, 30, 50 µM AlCl3).Demir 2000 wheat (Triticum aestivum L.) genotypes secreted metabolites when there is Al in the growth medium, which is considered as a defense mechanism response given by plants against Al stress.Keywords: Wheat, Al, NMR Spectroscopy, Secondary Metabolites, Antioxidative Enzymes 73