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Fungal ve Arkeal Kaynaklı Lipazların Eldesi, Aktivitelerinin Kıyaslanması ve Kağıt Üretiminde Kullanımı
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The potential of archaeosomes as carriers of pDNA into mammalian cells
No full textThis paper describes the formulation of archaeosomes and the evaluation of their abilities to facilitate in vitro DNA delivery. Lipids of the H.hispanica 2TK2 strain were used in archaeosome formation, which is formulated by mixing H.hispanica 2TK2 lipids with plasmid DNA encoding green fluorescent protein (GFP) or beta-galactosidase (beta-gal). Archaeosome/pDNA formation and unbound DNA were monitored by agarose gel electrophoresis. The archaeosome formulations were visualized by AFM and TEM. The zeta potential analysis showed the archaeosomes to be electronegative. The composition of archaeosomes and the DNA dose for transient transfection into HEK293 cells were optimized, and the relationship between the structure and activity of archaeosomes in DNA delivery was investigated. By themselves, archaeosomes showed low efficiency for DNA delivery, due to their anionic nature. By formulating archaeosomes with a helper molecule, such as DOTAP, CaCl2, or LiCl, the capability of archaeosomes for gene transfection is significantly enhanced. The transfection profiles of efficient archaeosomes are proved to have a long shelf-life when maintained at room temperature. Thus, the archaeal lipids have the potential to be used as transfection reagents in vitro
Enzymatic activity of a novel halotolerant lipase from Haloarcula hispanica 2TK2
No full textA strain of Haloarcula hispanica isolated from Tuzkoy salt mine, Turkey exhibited extracellular lipolytic activity. Important parameters such as carbon sources and salt concentration for lipase production were investigated. Optimal conditions for the enzyme production from Haloarcula hispanica 2TK2 were determined. It was observed that the lipolytic activity of Haloarcula hispanica was stimulated by some of the carbon sources. The high lipase acitivity values were obtained in the presence of 2% (v/v) walnut oil (6.16 U/ml), 1% (v/v) fish oil (5.07 U/ml), 1% (v/v) olive oil (4.52 U/ml) and 1% (w/v) stearic acid (4.88 U/ml) at 4M NaCl concentration. Lipase was partially purified by ammonium sulfate precipitation and ultrafiltration. Optimal temperature and pH values were determined as 45 degrees C and 8.0, respectively. Lipase activity decreased with the increasing salt concentration, but 85% activity of the enzyme was maintained at 5M NaCl concentration. The enzyme preserved 41% of its relative activity at 90 degrees C. The partially purified lipase maintained its activity in the presence of surfactants such as Triton X-100 and SDS. Therefore, the lipase which is an extremozyme may have potential applications especially in detergent industry
Degradation Of Pitch Components In Recycled Cardboard Production Process By Fungal Lipase
Get PDFTez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2004Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2004Pitch maddelerinin biyolojik olarak arındırılması, kağıt endüstrisi için son yıllarda geliştirilmiş biyoteknolojik bir metoddur. Odun eksraktiflerinin kağıt makineleri üzerinde birikmesi, düşük kaliteli kağıt hamuru elde edilmesine ve blokajlara neden olur ki bu da üretimin durması, önemli ekonomik kayıplar, ürün kalitesini düşmesi ve zehirli atık su oluşması gibi sonuçlar doğurur Problemli pitch maddelerinin miktarı, kağıt üretimi esnasında biyolojik ve kimyasal işlemlerle azaltılabilir. Son yıllarda, bu problem doğal olarak pitch bileşkenlerini parçalayabilen ve odun üzerinde yaşayan funguslar kullanılarak aşılmaya çalışılmaktadır. Pitch parçalanmasında en başarılı olan funguslar Fusarium oxysporum ve Ophiostoma piliferum’dur. Bu funguslar triaçilgliseritleri hidrolize edebilen bir enzim olan lipaz üretir. Bu çalışmanın amacı, geri dönüşümlü kağıtta bulunan pitch bileşkenlerini analiz ederek bunları parçalamak için uygun bir yöntem geliştirmektir. Bu çalışmada, örneklerdeki triaçilgliserit, serbest yağ asidi, ester, hidrokarbon, mono ve diaçilgliseritler; bir gaz kromatografi cihazında ölçülmüştür. Kontrol olarak ticari enzimlerden Lipozyme IM, Lipozyme TL IM, Novozym 435 (Novo Nordisk) kullanılmıştır. Lipaz aktivitesi pH-stat cihazı ile ölçülmüştür. Hidroliz miktarını daha iyi saptamak amacıyla serbest yağ asitlerinin miktarı asit değeri tayini ile belirlenmiştir. Sonuçlar göstermiştir ki, F. oxysporum ve O. piliferum kültürlerinden elde edilen süpernatanlar geri dönüşümlü kağıt üretiminde pitch maddelerinin yok edilmesinde etkilidir.Biological pitch removal is a biotechnological method that has been developed recently for the paper and pulp industry. Accumulation of wood extractives in pulp and paper mills results in low-quality pulp and blockages that cause shutdowns of operations and important economic losses, reduces the quality of product and also create waste water toxicity. The amount of problematic pitch can be reduced by biological and chemical processes during paper production. In the recent years, this problem was tried to be solved by utilizing wood-dwelling fungi which naturally degrade pitch components. It has been shown that the two most successful fungi for pitch degradation are Fusarium oxysporum and Ophiostoma piliferum. These fungi produce lipases that hydrolyze triacylgyicerides. The aim of this study is to analyze the pitch components found in recycled paper to develop a suitable degradation method. Samples were analyzed on a GC to detect the amount of triacylgyicerides, free fatty acids, esters, hydrocarbons, mono and diacylglycerides. Commercial enzymes Lipozyme IM, Lipozyme TL IM, Novozym 435 from Novo Nordisk were used as controls. Lipase activity was assayed by using pH-stat. The amount of free fatty acids were also determined by acid value analysis in order to get a better quantification of the hydrolysis. Results demonstrated that F. oxysporum and O. piliferum growth medium supernatants can be efficiently used for pitch removal in recycled paper production.Yüksek LisansM.Sc
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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