Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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2003 - 200912010 - 20121

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Publisher: search.filters.publisher.Izmir Institute of TechnologySubject: search.filters.subject.Microbial biotechnology

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  • Master Thesis
    Screening for Industrially Important Extracellular Enzymes From Alkalophilic Bacillus Genus
    (Izmir Institute of Technology, 2003) Akbalık, Güney; Yenidünya, Ali Fazıl; Yenidünya, Ali Fazıl; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Alkalophilic Bacillus include industrially important species since they can produce many extracellular enzymes which are active and stable at high pH values.These alkaline enzymes (proteases, amylases, xylanases, cellulases, lipases and pectinases) find use in various field of industry such as leather, detergent, paper industries and waste water treatment.Isolation of diverse bacteria plays an important role in finding novel enzymes with improved characteristics. The aim of this study was therefore to screen for alkaline extracellular enzymes of alkalophilic Bacillus isolated from soil, horse feces and leather processing and to characterize these strains by phenotypic tests and by 16S-ITS rDNA based RFLP.At the end of the study, rod-shaped, endospore forming and Gram positive 116 strains were identified as Bacillus. Ten of the 116 strains were found to be obligate alkalophilic. 91 protease, 77 amylase, 18 xylanase, 3 cellulase, 74 pectinolytic enzyme (71 polygalacturonic acid degrading and 72 pectin degrading) and 55 lipase (41 Tween 20 hydrolyzing and 14 Tween 80 hydrolyzing) producing strains were obtained. Isolated and reference strains were classified into 18 groups in respect of the enzymes they produced.Two enzymes, Taq I and Hae III were used for 16S-ITS rDNA based RFLPanalysis. Both of the enzymes were found to be necessary for the discrimination of the strains. Reference strains were clustered into different groups by both Taq I and Hae III.Taq I digestion revealed 16 genotypic groups while Hae III revealed 15 different groups. And comparative analysis of the RFLP profiles of 116 isolates and 5 reference strains resulted in 26 genotypic groups.
  • Master Thesis
    Molecular Cloning, Overexpression and Biochemical Characterization of Bacterial Amylase for Biotechnological Processes
    (Izmir Institute of Technology, 2012) Burhanoğlu, Tülin; Şanlı Mohamed, Gülşah; Karakaya, Hüseyin Çağlar; Karakaya, Hüseyin Çağlar; Şanlı Mohamed, Gülşah; 04.03. Department of Molecular Biology and Genetics; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Amylases are the enzymes that act on glycosidic bond of starch and related polysaccarides. They comprise 25% of enzyme utilised in a variety of industry. It is used to obtain maltose, glucose and maltodextrins in various lenghts during industrial processes. Amylases are widely distributed enzymes in bacteria, fungi, higher plants and animals. Thermophilic enzymes are widely demanded in order to be stable at harsh process conditions. Isolating these enzymes from thermophilic microorganism is increasing trend because of ease of enzyme production. In this study α-amylase gene region from a thermophilic Bacillus sp. isolated from Balçova Geotermal region in İzmir was cloned to compotent E. coli BL 21 cells. Additionally protein expression was reinforced with pKJE7 chaperone plasmid. Cloned gene was sequenced and found as 1542 bp in length. Thermophilic amylase that has a 59.9 kD molecular weight was expressed and purified from this recombinant strain. Mass spectrometric analysis were performed and the enzyme was matched with α-amylase family protein of Geobacillus thermodenitrificans NG80-2 using NCBInr database. The aminoacid sequence of this enzyme was seen to be similar 92% with our obtained enzyme. According to the results of characterization studies, the amylase enzyme was seen to have highest activity at pH 8.0 and 60°C. The enzyme was also showed to have resonable activity between pH5 and 9. 85% of the enzyme activity was retained at 70°C. Furthermore, amylase activities at 65 and 85°C were observed to remain stable for 5 and 2 hours, respectively. It was also showed that the activity was stable and pH7 and 9 for 6 hours. The effects of some metal ions, chemical agents and organic solvents on enzyme activity were examined so, Co+2, Mg+2,Ca+2 was determined to be as inducer for the enzyme activity. Conversely the activity was inhibited by Cu+2. Furthermore methanol, DDT and Triton X-100 was found to have no effect on the enzyme activity.