Vpliv spreminjanja pogojev gojenja v kontinuirnem bioprocesu na rastne parametre bakteriofaga T4

Stošicki, Janja (author), Podgornik, Aleš (mentor)

Bakteriofagi so virusi, ki lahko okužijo in ubijejo bakterijske celice. Kmalu po odkritju so bili uporabljeni za zdravljenje bakterijskih okužb, vendar so takratne študije zaznamovale številne pomanjkljivosti, poleg tega je sledilo odkritje antibiotikov, kar je skupaj večinoma zavrlo razvoj fagne terapije. Zaradi vse pogostejših bakterijskih sevov, odpornih na številne antibiotike, ter boljšega poznavanja biologije bakteriofagov, je preučevanje fagne terapije ponovno v zagonu. Poleg raziskav je potrebno razviti tudi učinkovite načine proizvodnje bakteriofagov. Kontinuirni sistemi kot je cellstat se lahko uporabljajo tako za proizvodnjo bakteriofagov, kot tudi za laboratorijsko evolucijo za pridobitev učinkovitejših bakteriofagov za uporabo v zdravljenju in diagnostiki. V sklopu tega magistrskega dela smo uporabili kontinuirni sistem – cellstat, v kateremu smo tekom 14 dni poviševali hitrost razredčevanja bioreaktorju z bakteriofagi. Po vsaki spremembi hitrosti redčenja smo iz sistema izolirali vzorec bakteriofagov, na katerih smo preučevali tri fagne parametre (latentno periodo, pomnožitveno število, konstanto adsorbcije) in izračunali fitnes oziroma hitrost rasti. Te vrednosti smo nato primerjali z vrednostmi, ki so bile določene začetni populaciji bakteriofagov. Z višanjem hitrosti redčenja smo res pridobili bakteriofage z naraščajočim fitnesom, vendar so se pri najvišjih hitrostih redčenja bakteriofagi najverjetneje že začeli spirati iz sistema.

• Language: Slovenian
• Keywords: Fag T4, E. coli, latentna perioda, pomnožitveno število, konstanta adsorbcije, fitnes
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [J. Stošicki]
• Year: 2022
• PID: 20.500.12556/RUL-134632
• UDC: 602.3:578.347:602.42:577.152.3: 606:61(043.2)
• COBISS.SI-ID: 95344131
• Publication date in RUL: 22.01.2022

STOŠICKI, Janja, 2022, Vpliv spreminjanja pogojev gojenja v kontinuirnem bioprocesu na rastne parametre bakteriofaga T4 [online]. Master’s thesis. Ljubljana : J. Stošicki. [Accessed 19 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=134632

Secondary language

• Language: English
• Title: Effect of changing conditions during continuous production on phage parameters of phage T4

Abstract

Bacteriophages are viruses, capable of infecting and lysing bacterial cells. Soon after discovery, they were used for treating bacterial infections, however due to poorly executed studies and discovery of antibiotics, phage therapy was no longer pursued. Nowadays, because many bacterial strains have become resistant to antibiotics, and we have a better understanding of phage biology, phage therapy is gaining new momentum. In addition to research, effective ways of producing bacteriophages, also need to be developed. Continuous systems, such as cellstat, can be used for production and for laboratory evolution of bacteriophages to obtain more effective bacteriophages to be used for treatment or diagnostics. During our experiments, we used cellstat continuous system in which we increased dilution rate in second bioreactor over a two-week span. After each increase in dillution rate, we isolated phages from the system, determined all phage parameters (latent period, burst size, adsorbtion constant) and calculated fitnes or growth rate for each sample. Obtained values were compared with values for initial phage sample (working bank). With increasing dillution rates, we isolated phages with higher growth rates, however at highest growth rates, phages had started to wash out of the system.

• Keywords: Phage T4, E. Coli, latent period, burst size, adsorbtion constant, fitnes