Funkcionalna svojstva površinskog proteina bakterije Lactobacillus acidophilus M92

master's thesis

• Title (english): Functional properties of the surface protein in bacteria Lactobacillus acidophilus M92
• Author: Zrinka Kršek
• 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: 2007-05-03, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

U prethodnim istraživanjima, dokazana su probiotička svojstva tri soja bakterija mliječne kiseline: Lactobacillus acidophilus M92, Lactobacillus plantarum L4 i Enterococcus faecium L3. Probiotički soj Lactobacillus acidophilus M92 je pokazao najbolja imunomodulacijska svojstva što bi se moglo pripisati površinskom parakristalnom sloju, tzv. S-layer proteinu. Osim što potiče sintezu ukupnih IgA, IgG i IgM antitijela u serumima imuniziranih miševa, S-layer protein utječe i na bolje preživljavanje Lactobacillus acidophilus M92 u simuliranim uvjetima želučanog soka i soka tankog crijeva, kao i tijekom priprave suhog bakterijskog preparata Lactobacillus acidophilus M92 liofilizacijom, što ukazuje na njegovu zaštitnu ulogu. Također, pokazalo se da je Sprotein odgovoran za adheziju Lactobacillus acidophilus M92 na epitelne stanice tankog i debelog crijeva miševa u in vitro i in vivo pokusima. Nakon infekcije miševa s patogenom bakterijom Salmonella enterica serovar Typhimurium, a koji su prethodno bili hranjeni s probiotičkim sojem Lactobacillus acidophilus M92, broj patogenih stanica u njihovom intestinalnom sustavu bio je 50% manji nego u miševa koji nisu bili tretirani s probiotičkim bakterijama. Adhezija ispitivanih probiotičkih sojeva u tankom i debelom crijevu pokusnih miševa potvrđena je induciranjem rezistencije ovih sojeva na rimfampicin te identifikacijom izoliranih bakterijskih sojeva iz crijeva miševa RAPD-PCR metodom.

Abstract (english)

In previous researches, three strains of Lactic Acid Bacteria with probiotic properties have been defined: Lactobacillus acidophilus M92, Lactobacillus plantarum L4 and Enterococcus faecium L3. Probiotic strain of L. acidophilus M92 has shown the highest immunomodulatory properties that could be attributed to the paracrystalline layer so called S-layer protein. Besides stimulating the synthesis of total IgA, IgG and IgM antibodies in immunized mice serum, S protein influences enhanced survival of L. acidophilus M92 under simulated conditions of gastric juice and intestinal juice, as well as during preparation of dry bacterial culture using lyophillization proving its protective function. Also, adhesive function of L. acidophilus M92 S protein has been shown on epithelial cells of mice small and large intestine in vitro as well as in vivo tests. After injecting mice, previously fed with probiotic strain of L. acidophilus M92, with pathogenic bacteria Salmonella enterica serovar Typhimurium, number of pathogenic cells in their intestinal system was 50% smaller compared to mice that were not fed with probiotic bacteria. Adhesive function of tested probiotic strains in the small and large intestine of experimental mice has been confirmed by inducing the resistance of these strains on rimphampicin, and by identification of isolated bacterial strains out of mice intestine by RAPD-PCR method.

• Keywords: adhezija; ELISA; imunomodulacija; Lactobacillus acidophilus; RAPDPCR; S-sloj
• Keywords (english): adhesion; ELISA; immunomodulation; Lactobacillus acidophilus; RAPDPCR; S-layer
• Language: croatian
• URN:NBN: urn:nbn:hr:159:214067
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-06 12:54:49