Entwicklung einer biotechnologischen Produktionsstrategie für das Sesquiterpenoid Zerumbon

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Image as a narrative in architecture

Günümüz görsel kültür ortamında indirgemeci bir yaklaşımla tek katmanlı olarak ele alınan imge kavramının zihinsel soyutlama yeteneğini zayıflattığı, düşünsel üretimin araçsallaştırılmasına neden olduğu düşünülmektedir. Bu bağlamda, mimarlıkta eleştirel düşünceyi tetikleyen imge kavramına farklı disiplinlerin penceresinden bakmak, farklı kavramlarla onu yeniden anlamlandırmak gerekmektedir. Bu çalışmada, nesnel biçimden zihinsel kurgu temsiline uzanan geniş bir yelpazede anlamlandırılan imge sorunsalı, eleştirel bir bakış açısıyla irdelenmekte ve mimarlıkta ilişkisel bilginin üretimine yol açabilecek bir okuma yöntemi önerilmektedir. Gündelik dilde görüntü ve biçim yerine kullanılan imgenin, biçime indirgenen yüzeysel algılama ve düşünme süreçlerine karşın imgeyi bir “anlatı olarak okuma”nın mimarlık bilgisinin üretimi için alternatif bir yaklaşım olabileceği tartışılmaktadır. Anlatı, zamansal deneyimin özelliklerini gösterdiği ölçüde yapılı çevrenin olay örgüsüne gönderme yapar. Anlatı olarak imge, bütüncül bir bakış açısı ile elde edilen mimarlık bilgisine ait “büyük resmi” bir olay örgüsüne dönüştürür. Herhangi bir yapılı çevreye ait imgenin katmanlı yapısı ve bu katmanlar arası ilişkileri bir olay örgüsüne dönüştürme sürecinde anlama, doğrusal düşünme biçimi yerine ağ ilişkisi ile temsil edilen karmaşık bir düşünme biçimini zorunlu kılar. Bu çalışmada imgeyi bir anlatı olarak okuma yöntemi, ilişkisel bilgiye ulaşmada bir örneklem olarak Kayseri Sahabiye Mahallesi imgesi üzerinden önerilmektedir. Tikel bir durum olan Sahabiye Mahallesi örneklemini genellenebilir kuramsal bilgi ile ilişkilendirerek deneyimleme; diğer bir deyişle, yapılı çevrenin katmanlı imge okumasını - tikel ve genel arasında gidip gelme hareketiyle eklenerek çoğalan ilişkisel bilgiye dönüştürme stratejisi, tezin kendine özgü yöntemini açıklamaktadır. Anahtar Kelimeler: Görsel kültür, imge, eleştiri, ilişkisel bilgi, anlatı / olay örgüsü. This study, proposes a method for the use of the "image" in architectural criticism, which is perceived as problematic of being a single layered, reductionist concept and dominating the mental processes figuratively. In everyday language, it is being used to define a wide spectrum of meanings from figural to the mental and expresses the thought, representation and criticism. For this reason, to redefine the concept of image as a narrative became necessary, in the field of architecture. In this study, it is argued that, reading the image as a narrative will recover the concept being shallow and reductionist, as it is understood extensively. It is thought that, reading the image as a narrative can be used as a key concept to generate the architectural knowledge from the built environment. In this context, it is thought that understanding and interpreting the "big picture" of architecture can be presented according to the holistic approach. Consequently, the image is presented with its multi-layered properties and the relations between these layers are important in understanding the meaning of the concept, which emerges within the network relations. This relationship requires both a mental process that will include the subject's background and priorities and the affordances of the environment. The narrative of the image is therefore thought to be emerged as the interactive relationship of the object and the subject. It is thought that, the cities, as living spaces having cultural codes, cannot be understood only by syntactic and analytic methods. Togetherness of the subject and the object is needed in order to solve the puzzle like structures of these environments. In such an understanding, the researcher has to experience the research area using her intentionality and try to find out the relations hidden among the layers of the environment. These relations can be considered as "a fold", as a Deleuzian concept, which allows all the layers reflect each other, and make visible the other. The intentionality of the researcher caused by the synergy of these relations will produce a fertile ground for exploring new layers of meanings that cannot be seen only by looking at. Image, considered as a mental construct, represents the subjective thought and the knowledge of the phenomenon can include many meanings. In architectural criticism, it is important to recognize the word as a loaded concept, and not to prefer or stick one of the meanings. According to the holistic approach, none of them is more important than the other, and the whole is greater than the parts. Reading the image of Sahabiye District in Kayseri as a narrative has been considered as an exemplar in this study. It is difficult to explain how to read the image of Sahabiye District as a narrative because of its multi-layered and complex structure having too many cultural codes superimposed within old and new environments. To recognize the experiential, cultural, historical, textural and social contrasts in the district makes its image multi-layered while reading the image as a narrative. The inexhaustibility of contrast (Ross, 1994), proposes an unlimited energy resulting from the tension of the opposing but complementary concepts. This tension makes each of these concepts being visible simultaneously. Sustainability referring to both continuity and change which represents contrast is another concept facilitates reading the image of Sahabiye District. The researcher, as an old resident of the district has a sustainable experience in there. The first-person phenomenological research method (Seamon, 2003) is adapted in this research in order to understand the deep meaning of this experience. Multi layered character of the image of this district, besides the empathic devotion and the theoretical background of the researcher makes the image of the Sahabiye District an exemplar give rise to relational knowledge. In this research, it is emphasized that reading the image of a build environment as a narrative can be translated to a generalized and sustainable knowledge which is contextual and specific to this environment. Reading the image of Sahabiye District as a narrative therefore exemplifies the proposed method based on web of events which is open to critical knowledge. As an exemplar, narrating Sahabiye  District will give rise to an in-between reality concerning singularity and multiplicity and having a potential to move between a specific and general knowledge. As a result, reading the image as a narrative in architectural environments introduces some possibilities for translating the multi-layered structures of the cityscape to critical knowledge that can be used for preservation and gentrification projects. Keywords: visual culture, image, architectural criticism, relational knowledge, narrative / web of event

Heterologous Expression, Purification, and Biochemical Characterization of α-Humulene Synthase from Zingiber zerumbet Smith

The α-humulene synthase from Zingiber zerumbet Smith was expressed as a polyhistidine-tagged protein in an E. coli BL21(DE3) strain. Induction time and inductor (isopropyl-β-D-thiogalactopyranoside) concentration were optimized. The enzyme was successfully purified directly from cell lysate by NTA affinity column chromatography and careful selection of coordinated metal ion and imidazole elution conditions. Bioactivity assays were conducted with the natural substrate farnesyl diphosphate (FDP) in a two-phase system with in situ extraction of products. The conversion of FDP to α-humulene (~94.5 %) and β-caryophyllene (~5.5 %) could be monitored by gas chromatography-flame ionization detection (GC-FID). Optimal pH and temperature as well as kinetic parameters KM and kcat were determined using a discontinuous kinetic assay. The final publication is available at Springer via http://dx.doi.org/10.1007/s12010-015-1888-4.EFRE/ZW-8-8013094

Characterisation of a Recombinant Patchoulol Synthase Variant for Biocatalytic Production of Terpenes

The patchoulol synthase (PTS) is a multi-product sesquiterpene synthases which is the central enzyme for biosynthesis of patchouli essential oil in the patchouli plant. Sesquiterpene synthases catalyse the formation of various complex carbon backbones difficult to approach by organic synthesis. Here, we report the characterisation of a recombinant patchoulol synthase complementary DNA (cDNA) variant (PTS var. 1), exhibiting significant amino acid exchanges compared to the native PTS. The product spectrum using the natural substrate E,E-farnesyl diphosphate (FDP) as well as terpenoid products resulting from conversions employing alternative substrates was analysed by GC-MS. In respect to a potential use as a biocatalyst, important enzymatic parameters such as the optimal reaction conditions, kinetic behaviour and the product selectivity were studied as well. Adjusting the reaction conditions, an increased patchoulol ratio in the recombinant essential oil was achieved. Nevertheless, the ratio remained lower than in plant-derived patchouli oil. As alternative substrates, several prenyl diposphates were accepted and converted in numerous compounds by the PTS var. 1, revealing its great biocatalytic potential. The final publication is available at Springer via http://dx.doi.org/10.1007/s12010-015-1707-yEFRE/ZW-8-8013094

SUMO-fusion, purification, and characterization of a (+)-zizaene synthase from Chrysopogon zizanioides

An uncharacterized plant cDNA coding for a polypeptide presumably having sesquiterpene synthase activity, was expressed in soluble and active form. Two expression strategies were evaluated in Escherichia coli. The enzyme was fused to a highly soluble SUMO domain, in addition to being produced in an unfused form by a cold-shock expression system. Yields up to ∼325 mg/L−1 were achieved in batch cultivations. The 6x-His-tagged enzyme was purified employing an Ni2+-IMAC-based procedure. Identity of the protein was established by Western Blot analysis as well as peptide mass fingerprinting. A molecular mass of 64 kDa and an isoelectric point of pI 4.95 were determined by 2D gel electrophoresis. Cleavage of the fusion domain was possible by digestion with specific SUMO protease. The synthase was active in Mg2+ containing buffer and catalyzed the production of (+)-zizaene (syn. khusimene), a precursor of khusimol, from farnesyl diphosphate. Product identity was confirmed by GC–MS and comparison of retention indices. Enzyme kinetics were determined by measuring initial reaction rates for the product, using varying substrate concentrations. By assuming a Michaelis–Menten model, kinetic parameters of KM = 1.111 μM (±0.113), vmax = 0.3245 μM min−1 (±0.0035), kcat = 2.95 min−1, as well as a catalytic efficiency kcat/KM = 4.43 × 104 M−1 s−1 were calculated. Fusion to a SUMO moiety can substantially increase soluble expression levels of certain hard to express terpene synthases in E. coli. The kinetic data determined for the recombinant synthase are comparable to other described plant sesquiterpene synthases and in the typical range of enzymes belonging to the secondary metabolism. This leaves potential for optimizing catalytic parameters through methods like directed evolution.EU/EFRE/ZW-8-8013094

FEN BİLİMLERİ ENSTİTÜSÜ/LİSANSÜSTÜ TEZ PROJESİ

HAVA KİRLETİCİLERİ OLARAK POLİKLORLU BİFENİLLER (PCB

HAVA KİRLETİCİLERİ OLARAK POLİKLORLU BİFENİLLER

HAVA KİRLETİCİLERİ OLARAK POLİKLORLU BİFENİLLE

The effect of different materials on the coating of baker's yeast (Saccharomyces cerevisiae) with the fluidized bed method

Baker's yeast (BY) is very sensitive to moisture and can lose its activity by working at very low moisture contents. The main purpose of this study is to obtain dry yeast which can be used in ready flour mixtures with no negative effects by preventing moisture transfer from the environment, and which can be stored for a long period. In order to accomplish this purpose, BY was coated in a fluidized bed by using edible films and coating technology, which can be used in the food industry in order to increase the shelf life of foods and improve the product quality. The results show that the Wurster coating method was most effective in the coating of yeast on the fluidized bed drier, and the combination of palm oil, gelatin, and pectin ensured the best results in terms of low water vapor permeability, high yeast activity, and high solubility.TUBITAK-TEYDEB 1505 [5160078]; Pak Gida Uretim ve Pazarlama A.S.This research was supported by TUBITAK-TEYDEB 1505 (Project number 5160078) and Pak Gida Uretim ve Pazarlama A.S