Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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Conference Object Citation - WoS: 1Kinetic and Thermodynamic Properties of Crude and Three-Phase Partitioned Polygalacturonase From Aspergillus Sojae(Elsevier, 2007) Doğan, Nergiz; Tari, Canan; Göğüş, NihanCommercial preparations of pectinolytic enzymes derived from fungi are well known to have high biotechnological value in the industry. Since potential applications of pectinases in vari- ous fields of food, paper, textile and waste water treatment are increasing, it is important to understand the properties of these enzymes for efficient and effective usage.Conference Object Effect of Symbiotic Relationship of Lactobacillus Butgaricus 77 and Streptococcus Thermophilus 9512 on Betagalactosidase and Lactic Acid Production(Elsevier, 2007) Üstok, Fatma Işık; Tari, Canan; Harsa, ŞebnemEnzyme production which is a growing field of biotechnology has an annual world sale close to billion dollars. Therefore isolation of new strains producing novel enzymes is important for industrial enzyme production.Conference Object Citation - WoS: 1Optimization of Exo-Polygalacturonase Production From Orange Peel by Aspergillus Sojae(Elsevier, 2010) Büyükkileci, Ali Oğuz; Tarı, Canan; Fernandez-Lahore, H. M.; Gençkal Demir, Hande; Göğüş, NihanPectinases catalyze the degradation of pectic substances, thus they are used extensively in fruit juice and wine industry to facil-itate extraction and clarification. Aspergillus species, in particular Aspergillus niger, have long been utilized for production of pectinases. Previous studies of our group showed that A. sojae has a potential to produce enhanced amount of polygalacturonase, which is one of the pectic enzymes, in both submerged and solid-state cultures (Gogus et al., 2006; Tari et al., 2007). In this study, several agricultural products were screened in an effort to find a cheap and abundant substrate for submerged polygalacturonase production using a UV-mutated A. sojae strain. Medium composition was optimized to further enhance the enzyme level. Experiments were designed and analyzed statistically using the trial version of the statistical software, Design Expert.Article Citation - WoS: 13Citation - Scopus: 15Cytotoxic Tolerance of Healthy and Cancerous Bone Cells To Anti-Microbial Phenolic Compounds Depend on Culture Conditions(Humana Press, 2019) Karadaş, Özge; Meşe, Gülistan; Özçivici, EnginCarnosol and carnosic acid are polyphenolic compounds found in rosemary and sage with known anti-oxidant, anti-inflammatory, and anti-microbial properties. Here, we addressed the potential use of carnosol and carnosic acid for in vitro bone tissue engineering applications, specifically depending on their cytotoxic effects on bone marrow stromal and stem cells, and osteosarcoma cells in monolayer and 3D cultures. Carnosol and carnosic acid displayed a bacteriostatic effect on Gram-positive bacteria, especially on S. aureus. The viability results indicated that bone marrow stromal cells and bone marrow stem cells were more tolerant to the presence of carnosol compared to osteosarcoma cells. 3D culture conditions increased this tolerance further for healthy cells, while not affecting the cytotoxic potential of carnosol for osteosarcoma cells. Carnosic acid was found to be more cytotoxic for all cell types used in the study. Results suggest that phenolic compounds might have potential use as anti-microbial and anti-carcinogenic agents for bone tissue engineering with further optimization for controlled release.Article Citation - WoS: 21Citation - Scopus: 21Development of Adjuvant Nanocarrier Systems for Seasonal Influenza a (h3n2) Vaccine Based on Astragaloside Vii and Gum Tragacanth (aps)(Elsevier, 2019) Yakuboğulları, Nilgün; Genç, Rukan; Coven, Fethiye; Nalbantsoy, Ayşe; Bedir, ErdalAdjuvants are chemical/biological substances that are used in vaccines to increase the immunogenicity of antigens. A few adjuvants have been developed for use in human vaccines because of their limitations including lack of efficacy, unacceptable local or systemic toxicity, the difficulty of manufacturing, poor stability, and high cost. For that reasons, novel adjuvants/adjuvant systems are under search. Astragaloside VII (AST-VII), isolated from Astragalus trojanus, exhibited significant cellular and humoral immune responses. The polysaccharides (APS) obtained from the roots of Astragalus species have been used in traditional Chinese medicine and possess strong immunomodulatory properties. In the present study, the immunomodulatory effects of a newly developed nanocarrier system (APNS: APS containing carrier) and its AST-VII containing formulation (ANS: AST-VII + APNS), on seasonal influenza A (H3N2) vaccine were investigated. Inactivated H3N2 alone or its combinations with test compounds/formulations were intramuscularly injected into Swiss albino mice. Four weeks after immunization, the immune responses were evaluated in terms of antibody and cytokine responses as well as splenocyte proliferation. APNS demonstrated Th2 mediated response by increasing IgG1 antibody titers, whereas ANS showed response towards Th1/Th2 balance and Th17 by producing of IFN-gamma, IL-17A and IgG2a. Based on these results, we propose that APNS and ANS are good candidates to be utilized in seasonal influenza A vaccines as adjuvants/carrier systems. (C) 2019 Elsevier Ltd. All rights reserved.Correction Citation - WoS: 2Citation - Scopus: 2Correction: Scaffold-Free Three-Dimensional Cell Culturing Using Magnetic Levitation(Royal Society of Chemistry, 2018) Türker, Esra; Demircak, Nida; Arslan Yıldız, AhuThe authors regret the inclusion of an incorrect figure caption for Fig. 2. The corrected figure caption for Fig. 2 is shown below. Fig. 2 Evaluation of levitation height (z) and density profiles through magnetic levitation. (A) Gd(III) chelates were named as Gx (Gadovist/Gadobutrol), Dx (Dotarem/Gadoteric acid) and Ox (Omniscan/Gadodiamide). (B) Standard curve for PE bead density against levitation height; linear curve fitting gives the standard function for the corresponding curve. (C–E) Levitation height profiles of single NIH 3T3 cells under 30/50/100/200 mM Gd concentrations. Single cell density profiles calculated through standard function of linear fitting.Conference Object Citation - WoS: 1Microbial Transformation of Ruscogenins by Cunninghamella Blakesleeana(Georg Thieme Verlag, 2016) Özçınar, Özge; Tağ, Özgür; Kıvçak, Bijen; Bedir, ErdalThe natural product drug discovery process involves the isolation of new molecules from natural sources, investigation of their biological activities, and semi-synthesis of more active analogs. Microbial transformation plays a vital role in the preparation of new oxygenated derivatives, and has frequently been used as microbial model of mammalian drug metabolism [1,2]. It has been proved that the hydroxylation of steroidal compounds is catalyzed by cytochrome P450 monoxygenase systems, which exist in all eucaryotic microorganisms [3]. Cunninghamella genus has been widely used in transformation of steroids [4,5]. The major steroidal saponins of Ruscus aculeatus, ruscogenin and neoruscogenin, has strong anti-inflammatory activities, acts as an anti-elastase, and decreases capillary permeability [6]. In the present study microbial transformation of Neoruscogenin:Ruscogenin (78:22) mixture by Cunninghamella blakesleeana fungus afforded three new compounds. The structures were elucidated by LC-MS, 1D- and 2D NMR analyses as shown below. Mainly oxydation products were obtained from neoruscogenin by C. blakesleana. As far as can be ascertained from the literature, this is the first microbial transformation study performed on neoruscogenin.Conference Object Bioassay Guided Isolation of Naphthoquinones From Onosma Aksoyii, Investigation of Their Cytotoxic Properties(Georg Thieme Verlag, 2019) Kul, Demet; Karakoyun, Çiğdem; Yılmaz, Sinem; Pirhan, Ademi Fahri; Bedir, ErdalThe genus Onosma L. (Boraginaceae) includes about 230 species, distributed mainly in the Mediterranean region and Central Asia. Major constituents of Onosma species are alkaloids, naphthoquinones, polyphenols, phytosterols, terpenoids and fatty acids [1], [2]. Naphthoquinones are naturally widespread secondary metabolites deriving from some higher plants, fungi and bacteria. They exhibit significant biological activities such as cytotoxicity, antimalarial, antibacterial, antifungal and wound healing [2], [3]. Recently naphthoquinone derivatives have also been recognized as potent topoisomerase inhibitors [4].Conference Object Semi-Synthetic Studies on Astragaloside Vii and Immunomodulatory Activities of the Derivatives(Georg Thieme Verlag, 2019) Yakuboğulları, Nilgün; Sağ, Duygu; Çağır, Ali; Bedir, ErdalAdjuvants have been used in vaccine sector since 1920s to increase the immunogenicity of antigens, reduce the dosage and minimize frequency of immunizations [1]. The use of saponins as adjuvant in the prophylactic/therapeutic human and veterinary vaccines, and investigation of their immunomodulatory activities have gained importance in recent years [2],[3]. Astragaloside VII (AST VII), a triterpenoid saponin isolated from Astragalus species, stimulates Th1 mediated immune response, antigen-specific antibody response and splenocyte proliferation.Conference Object Induction of Secondary Metabolism of Marine Derived Streptomyces Cacaoi(Georg Thieme Verlag, 2019) Gezer, Erkin; Bilgi, Eyüp; Küçüksolak, Melis; Bedir, ErdalMicrobial natural products have an adaptive role as signal molecules or defense tools in ecological interactions. Biosynthesis of these molecules is suppressed in standard laboratory conditions where there are no ecological triggers. Thus, only a portion of the chemical diversity of a microbial strain is discovered by standard fermentation protocols. However, using different fermentation conditions or different approaches such as co-culture, biosynthesis of these suppressed molecules can be triggered, and new natural products can be isolated.
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