Interaction of lignin derivatives with polymers, ions and soft surfaces in aqueous systems

Lignin is one of the most abundant biopolymers on earth which has recently gained considerable attention due to its unique potentials to be used in many applications. Many efforts have been made in improving the compatibility and reactivity of lignin for different applications. Although different methods have been suggested to ameliorate lignin properties, there has been a continuous demand for finding effective and new ways of revealing the beneficial uses of this polymer. To address the lack of fundamental understanding of lignin modification pathways in generating lignin-based products, the chemical reactions conducted via grafting functional groups of lignin has been comprehensively reviewed in this thesis. Also, the recent progress on lignin reactions as well as advantages and disadvantage, challenges associated with the product development process, and the reaction procedures have been discussed comprehensively in this work. Also, from the commercial point of view, products such as vanillin and phenol have been commercially available since 1933 and 2015, respectively, with equal or lower prices to their fossil-based counterparts. Lignin-based carbon fiber is also estimated to be produced commercially in 2020-2025. Overall, by reviewing different reactions performed on lignin in this chapter and revealing the possible ones that could be implemented, lignin-based polymers with improved properties could be generated to pave the way to even more commercial products from lignin

Keratinolytic protease production and characterization from Bacillus sp. isolated from poultry wastes.

TEZ10350Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2014.Kaynakça (s. 83-95) var.xi, 97 s. : res. (bzs. rnk.), tablo ; 29 cm.Mikroorganizma temelli keratinazlar; keratin içerikli atıkların geri dönüşümü, deri, tekstil, yem, deterjan endüstrisi, medikal uygulamalar, gibi birçok endüstriyel alanda kullanılmaktadır. Bu çalışmada Çukurova Üniversitesi Araştırma-Uygulama ve Tavuk İşletme Ünitesi atıklarından 42 adet Bacillus suşu izole edilmiştir. İzolatlardan 8 tanesi skim-milk agarda proteolitik aktivite ve temel tüylü besiyerinde üretildiğinde keratin-azure ile keratinolitik aktivite göstermiştir. Keratinaz aktivitesi en yüksek olan H62 nolu suş keratinaz üreticisi olarak belirlenmiş, mikroskobik (Gram +, endospor +, basil), biyokimyasal (VITEK-2, %90) ve moleküler analiz (16S rRNA, %99, 9945A) ile Bacillus licheniformis olarak tanılanmıştır. Enzim üretim koşulları optimize edilmiştir. En yüksek enzim üretimi temel tüylü besiyerine (pH 7.0), 0.1 g/L mannitol (karbon kaynağı), 0.1 g/L amonyum nitrat (azot kaynağı) ve 15 g/L tavuk tüyü unu (feather meal) ilave edilerek 40°C’de, 45 saatte gerçekleşmiştir. Keratinaz pH 5.0-13.0 ve 20-90ºC’lerde aktivite göstermesine rağmen optimum aktivite pH 9.5 ve 40ºC’de gözlenmiştir. Enzim farklı tamponlarla (pH 7.0-13.00) 30 dk muamele edilmiştir. pH 8.0’de %100 kararlıklık saptanmışken, pH 7.0-9.0’dan sonra aktivite azalması gözlenmiştir. 20-100ºC’lerde 30 dk ön inkübasyondan sonra enzim 40ºC’de %100 kararlı iken diğer sıcaklıklarda aktivite kaybı gözlenmiştir. Oda sıcaklığında bekletildiğinde 24. saatten itibaren aktivitede azalma saptanmıştır. EDTA, SDS, Üre enzim aktivitesini arttırmış, Tween-20 azaltmıştır. SDS-PAGE analiziyle enzimin 26 kDa boyutunda tek band olduğu gözlenmiştir. Sonuç olarak B. licheniformis H62 keratinazı mezofil ve alkali koşullarda; özellikle medikal uygulamalarda ve yem katkısı olarak kullanılabilecek bir enzimdir.Keratinases originated from microorganisms are used in many industrial fields such as recycle of keratinous wastes, leather, textile, detergent industry and medical applications. In this study, 42 Bacillus strain were isolated from Cukurova University Research and Application and Chicken Management Unit. 8 of these isolates showed proteolytic activity on skim-milk and keratinolytic activity with keratin-azure when they were produced on the basal feather medium. Strain H62 with the highest keratinase activity was determined as the keratinase producer and identified as Bacillus licheniformis with microscopic (Gram +, endospor +, bacil), biochemical (VITEK-2, 90%) and molecular analysis (16S rRNA, 99%, 9945A). Conditions for enzyme production was optimized. The highest enzyme production was carried out at 40°C for 45 hours by adding 0.1 g/L mannitol (as carbon source), 0.1 g/L ammonium nitrate (as nitrogen source) and 15 g/L feather meal into the basal feather medium. Although keratinase showed the activity at 20-90°C and pH 5.0-13.0, optimum activity was obtained at 40°C and pH 9.5. Enzyme was treated with different buffers (pH 7.0-13.0) for 30 minutes. 100% of stability was determined at pH 8.0, whereas the loss of activity was observed at pH 7.0-9.0. After a pre-incubation at 20-100°C for 30 minutes enzyme was 100% stable whereas activity was decreased at the other temperatures. When the enzyme was hold on at the room temperature, a loss of activity was determined after 24th hour. EDTA, SDS and Urea increased the enzyme activity however Tween-20 was decreased. Enzyme was seem to be a single band with the molecular weight of 26 kDa. As a result, keratinase B. Licheniformis H62 is an enzyme that can be used in mesophile and alkali conditions, particularly in medical applications and as feed suplements.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: FEF2013YL34

Production of Flocculants, Adsorbents, and Dispersants from Lignin

Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed