Master Degree / Yüksek Lisans Tezleri

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

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Publisher: search.filters.publisher.Izmir Institute of TechnologySubject: search.filters.subject.Microencapsulation

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  • Master Thesis
    Developing Probiotic Lozenges To Improve Oral Health
    (Izmir Institute of Technology, 2019) Elvan, Menşure; Baysal, Ayşe Handan; Harsa, Hayriye Şebnem; Harsa, Hayriye Şebnem; Baysal, Ayşe Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Recently, there is a great need to overcome complaints about oral health from children, mental and physically handicapped people who are inadequate in oral hygiene and after chemotherapy of cancer patients. With reduced body resistance, opportunistic Streptococcus mutans and Candida albicans in the mouth become dominant, causing disruption of oral health. Therefore, the effect of lactic acid bacteria on pathogens was investigated in order to protect oral health with the thesis study. Lactobacillus pentosus NRRL-B 227 was determined among the probiotic bacteria tested for this purpose and its activity on the pathogen Streptoccocus mutans ATCC 25175 and Candida albicans DSMZ 5817 was found in broth microdilution, agar overlay and planktonic culture assays except disc diffusion test. To reduce the number of pathogens in oral microflora, lozenges containing L. pentosus were developed. Three different lozenges with encapsulated and free bacteria and control lozenge were produced, kept at different temperatures; 4⁰C and 25⁰C. No significant decrease in viability of the encapsulated probiotic strain after lozenge production and storage at 4°C was observed, the probiotic amount in the lozenge initially counted as 7.84 log CFU/g, while 7.73 log CFU/g at the end of 3 months shelf life. However, lozenges stored at 25⁰C probiotics lost their vitality after one month. Additionally, lozenges containing free bacteria have lost viability rapidly. Color and water activity were observed differently in the formulations (p <0.05). The formulations maintained their microbiological safety during storage. Lozenge with L. pentosus NRRL-B 227 has a significant potential for improving oral health and provides an alternative to the diversification of products containing probiotics.
  • Master Thesis
    Immobilization of Thermophilic Recombinant Esterase Enzyme by Microencapsulation in Alginate-chitosan/Caci2 Polyelectrolyte Beads
    (Izmir Institute of Technology, 2011) Tercan, Cisem; Şanlı Mohamed, Gülşah; Şanlı Mohamed, Gülşah; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    In recent years, enzyme immobilization has gained importance for design of artificial organs, drug delivery systems, and several biosensors. Polysaccharide based natural biopolymers used in enzyme or cell immobilization represent a major class of biomaterials which includes agarose, alginate, dextran, and chitosan. Especially, chitosan has used many biomedical applications, including tissue engineering, because of its biodegradability and biocompatibility, non-toxicity and degradation in the body. In this research, Recombinant esterase enzyme was purified from Thermophilic Bacillus sp. That was isolated from Balçova (Agamemnon) Geothermal region in İzmir by using one-step affinity purification chromatography. In the second step, purified enzyme encapsulated in alginate-chitosan/CaCl2 polyelectrolyte beads that were prepared by adding dropwise a protein-containing sodium alginate mixture into a chitosan-CaCl2 crosslinker solution. And then the polyelectrolyte beads were stabilized in at the same crosslinker solution 30 minutes more. In the third step, the effect of different conditions were tested such as temperature and pH, bead diameter, reuse of beads. Also the effects of inhibition of CaCl2, ZnCl2, MgCl2, CuSO4, MgSO4, Sodium dodecyl sulfate (SDS) and Triton X-100 onto the immobilized and free enzyme activity were studied. In the last step, analysis of surface morphologies of polyelectrolyte beads were determined and examined by means of Scanning Electron Microscope.