Asimilacija kolesterola i prebiotičkih supstrata s odabranim probiotičkim sojevima bakterija mliječne kiseline

master's thesis

• Title (english): Assimilation of cholesterol and prebiotic substrates with selected probiotic strains of lactic acid bacteria
• Author: Ivona Jurišić
• Mentor: Jagoda Šušković (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2012-07-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Istraživanja u okviru probiotičkog koncepta provedena su sa odabranim sojevima bakterija mliječne kiseline (BMK) kao potencijalnim probiotičkim kulturama. Među odabranim sojevima BMK najviši stupanj preživljavanja u simuliranim uvjetima gastrointestinalnog trakta (GIT) pokazali su sojevi ZG2-25 i ZG3-17. Zbog naglog širenja antibiotičke rezistencije posljednjih godina ispitana je osjetljivost odabranih sojeva BMK na antibiotike. Uočena je osjetljivost odabranih sojeva BMK na sve ispitivane antibitike, s izuzetkom Lactobacillus vrsta koji su, zbog urođene rezistencije, bili rezistentni na vankomicin. Budući da se asimilacijom prebiotičkih supstrata postiže pojačani probiotički, odnosno sinbiotički učinak, ispitana je mogućnost asimilacije četiri prebiotička supstrata sa odabranim sojevima BMK. Pokazalo se da odabrani sojevi najbolje rastu u hranjivim podlogama s prebioticima manitolom i laktulozom. S obzirom da probiotički pripravci često sadrže više od jednog probiotičkog soja proveden je i test koegzistencije. Odabrani sojevi BMK ne pokazuju uzajamni antagonizam i mogu rasti kao združena kultura u istoj hranjivoj podlozi. Jedan od pozitivnih učinaka odabranih probiotičkih sojeva BMK je i asimilacija kolesterola. Za određivanje bazičnih i kiselih svojstava površine mikrobnih stanica korištena je metoda mikrobne adhezije na otapala te je soj ZG4-14 pokazao najveći postotak adhezije u kloroformu što upućuje na luţnata (elektron-donorska) svojstva površine bakterijskih stanica.

Abstract (english)

Research in the field of probiotic concept was conducted with selected strains of lactic acid bacteria (LAB) as a potential probiotic cultures. Among the selected strains of LAB strains ZG2-25 and ZG3-17 showed the highest survival level. Due to the rapid spread of antibiotic resistance during the last years, the sensitivity of selected LAB strains to antibiotics was examined. Selected LAB strains showed antibiotic sensitivity, except the Lactobacillus species, which are due to innate resistance resistant to vancomycin. Since the assimilation of prebiotic substrates achieves enhanced probiotic and synbiotic effect the possibility of assimilation four prebiotic substrates with selected LAB strains was examined. The selected strains grow best in nutrient media with prebiotics lactulose and mannitol. Given that probiotic preparations often contain more than one strain of probiotic the test of coexistence was performed. Selected LAB strains have not show mutual antagonism and have grown as paired in the same culture medium. One of the positive effects of selected probiotic LAB strains is the cholesterol assimilation. For the determination of basic and acidic properties of microbial cell surface the method of microbial adhesion to solvents was used. The strain ZG414 showed the highest percentage of adhesion to chloroform indicating alkaline (electron donor) properties of its surface.

• Keywords: odabrani sojevi bakterija mliječne kiseline; probiotičke bakterije; prebiotički supstrati; stres
• Keywords (english): selected strains of lactic acid bacteria; probiotic bacteria; prebiotic substrates; stress
• Language: croatian
• URN:NBN: urn:nbn:hr:159:281506
• Study programme: Title: Molecular Biotechnology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka molekularne biotehnologije (magistar/magistra inženjer/inženjerka molekularne biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-08 08:13:08