Panomycocin içeren kitosan-tpp nanopartikülleri : preparasyonu, karakterizasyonu ve insan dermatofitlerine karşı in vitro antifungal aktivitesinin belirlenmesi.

There is an increase in the incidence of superficial fungal infections. Especially, immuno-compromised patients, diabetic patients, obese and people having resistancy against a group of antifungal drugs are at great risk. In these patient groups the infection can become chronic and affect the deeper and living layers of the skin and can be life threatening if not treated effectively. However, drugs which are currently used in the therapy of dermatophyte infections are becoming less effective due to the serious side effects and resistance developed by the pathogens. Thus, there is a continuing need for new classes of antifungal compounds that have potent antifungal activity, improved safety and low tendency to elicit resistance. Among the different approaches, the discoveries of naturally occuring antifungal proteins with little or no toxicity towards mammalian cells are attracting increasing attention. Within the naturally occuring antifungal proteins the yeast killer proteins which are produced and secreted into the environment by yeast strains with a killer phenotype represent promising candidates as potential antifungal agents in the medical field. Among the most effective killer toxins, the K5 type toxin has been purified and characterized for the first time in our laboratory and named as Panomycocin. Panomycocin is an exo-β-1,3 glucanase with a molecular mass of 49 kDa. It kills the sensitive cells by hydrolysing the β-1,3-glucans which are vital polymers for the integrity of the fungal cell wall. In following studies we have formulated Panomycocin with chitosan-TPP nanoparticles, which are used for the encapsulation of therapeutic proteins and accepted as effective non-toxic carrier system and characterized the nanoparticles in terms of surface morphology, particle size, zeta potential, interactions between chitosan, TPP and Panomycocin and in vitro release of Panomycocin from chitosan-TPP nanoparticles. Lastly, we have determined in vitro antifungal activity of Panomycocin-incorporated chitosan-TPP nanoparticles against common human dermatophytes. All tested dermatophyte strains were found to be susceptible to Panomycocin-loaded CS-TPP NPs. MIC-0 range for Tricophyton species was found as 1-2 mg/ml and MIC-0 for Microsporum gypseum was found as 1.5 mg/ml. This study will enable the development of a new, highly selective antifungal drug for the topical treatment of human superficial infections. In addition to providing health benefits, Panomycocin will contribute to the economy as it is produced naturally.M.S. - Master of Scienc

İnorganik arsenik ve kadmiyum tayini için floresan tam hücre bakteriyel biyoraportörlerin geliştirilmesi.

Environmental heavy metal contamination in many regions of the world is a serious problem of ecological health. Fast and constant monitoring of their levels is significant for both preventing their accumulation and taking an immediate action for removal. As an alternative approach to standard laboratory techniques, various biosensor systems for detection of heavy metals have been proposed. Bacterial biosensors hold great promise for in-field detection of heavy metals. In this study, two different whole cell Escherichia coli bioreporter strains were developed for detection of inorganic arsenic and cadmium. In their presence, reporter gene expression increases which is detected as fluorescent signal later interpreted as a measure of available metal level in sample. Following cloning studies, arsenic and cadmium bacterial bioreporter strains were characterized for their metal specificity and detection limits by using different media and induction plans. In liquid assays, arsenic bioreporter could detect arsenite and arsenate at 10 μg/L after 2 hours, and cadmium bioreporter could detect cadmium of 2 μg/L after 1.5 hours of induction. Additionally, the arsenic bioreporter could estimate the bioavailable arsenic level in contaminated groundwater sample. To be integrated into a portable device, immobilization of arsenic bacterial bioreporter was investigated using agar and alginate biopolymers. Entrapment parameters of polymer concentration and cell density were evaluated. Immobilized cells were characterized for their metal specificity and detection limits by using different media. Agar and alginate immobilized bioreporter systems could detect arsenite and arsenate of 25 μg/L and 150 μg/L within 5 hours and 2 hours, respectively. The results demonstrated that these bacterial arsenic and cadmium bioreporter strains are applicable in determining the environmentally safe concentrations of these two most abundant heavy metals.Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Biotechnology

FEN BİLİMLERİ ENSTİTÜSÜ/LİSANSÜSTÜ TEZ PROJESİ

CLONİNG,SEQUENCİNG AND VERİFİCATİON OF İDENTİTİES OF THE EFFECTOR GENES İN PUCCİNİA STRİİFORMİS F.SP.TRİTİC

Immobilization of fluorescent bacterial bioreporter for arsenic detection

Whole-cell bacterial biosensors hold great promise as a practical complementary approach for in-field detection of arsenic. Although there are various bacterial bioreporter systems for arsenic detection, fewer studies reported the immobilization of arsenic bioreporters. This study aimed at determining immobilization of specific bacterial bioreporter in agar and alginate biopolymers to measure level of arsenite and/or arsenate. To achieve sensitive detection, immobilization parameters of polymer concentration and cell density were evaluated. Moreover, by changing the culture medium, immobilized bioreporter cells in minimal medium can detect arsenite while they can detect both arsenite and arsenate in phosphate-limited minimal medium. When optimal parameters were applied, agar and alginate immobilized bioreporter systems can detect arsenite and arsenate concentrations of 10 mu g/l and 200 mu g/l within 5 h and 2 h, respectively. The results showed that the immobilized bacterial bioreporter systems are able to determine the concentrations of the two abundant species of arsenic; arsenite and arsenate, as opposed to other studies which reported only arsenite detection. This is the first study describe agar hydrogel and alginate bead immobilization of fluorescent arsenic bacterial bioreporter that can detect both arsenite and arsenate at the safe drinking water limit. Thus, this study will enable further steps to be taken towards developing sensitive and selective portable devices to assess environmental arsenic contamination and prevent acute arsenic toxicity

Tam Hücre Bakteriyel Biyosensörleri Kullanılarak Sudaki Ağır Metallerin Tespit Edilmesi

Günümüzde insan odaklı ağır metal kullanımı ve ağır metal içeren atıkların arıtılmadan çevreye salımı giderek artmaktadır. Ağır metaller suda yüksek çözünürlüğe sahip oldukları için su sistemlerine kolayca karışabilmekte ve canlılarda toksik ölçüde birikebilmektedir. Sudaki ağır metal kirliliğini izlemek için fizikokimyasal analizlere dayanan konvansiyonel metotların yanında biyolojik metotların kullanımı giderek önem kazanmaktadır. Bu çalışma, rekombinant floresan tam hücre bakteriyel biyosensörleri geliştirilerek çevresel toksisitesi yüksek ağır metallerin sudaki konsantrasyonlarının belirlenmesine yönelik araştırmaları kapsamaktadır

Evaluation of novel thermo-resistant Micractinium and Scenedesmus sp for efficient biomass and lipid production under different temperature and nutrient regimes

Despite the vast interest in microalgae as feedstock for biodiesel production, relatively few studies examined their response to diurnal temperature fluctuation. Here, we describe biomass and lipid productivities and fatty acid profiles of thermo-resistant Micractinium sp. and Scenedesmus sp. grown in batch cultures in a laboratory set-up that mimics a typically warm summer day in Central Anatolia with a 16-h light temperature of 30 degrees C and 8-h dark temperature of 16 degrees C (30 degrees C (day)/16 degrees C (night)). Both strains can survive a temperature range of 10-50 degrees C. We found the lipid productivities of Micractinium sp. and Scenedesmus sp. as 30/21 mg L-1 d(-1) and 6/7 mg L-1 d(-1), respectively during the 30 degrees C (day)/16 degrees C (night) cycle. Saturated fatty acid content increased with increasing temperature. Additionally, we cultured Micractinium sp. under Nitrogen (N) and Phosphorus (P) limiting conditions. Highest lipid productivity of 85.4 +/- 2 mg L-1 d(-1) was obtained under P-depletion during exponential growth phase. Oleic acid amount also increased eight fold during P-deplete