magistrsko delo
Nina Kuzmić (Author), Aleš Podgornik (Mentor), Marjan Marinšek (Thesis defence commission member), Gabriela Kalčíková (Thesis defence commission member)

Abstract

Bakteriofagi so prisotni povsod okrog nas. Njihova ključna vloga je regulacija mikrobnega ravnovesja v različnih ekosistemih, prav tako pa se zaradi različnih prednosti, antibakterijskih učinkov ter naraščanja antibiotske rezistence vse bolj uporabljajo pri zdravljenju bakterijskih okužb ter v najrazličnejših medicinskih in okoljskih aplikacijah. Bakteriofagi za svoj obstoj potrebujejo bakterije in so njihovi naravni sovražniki. Sodelujejo v procesu infekcije in končne lize bakterije. Gojenje bakteriofagov v laboratorijskem merilu se običajno izvaja v stresalnih kulturah, medtem ko se v industriji uporabljajo šaržni procesi v bioreaktorjih. Pri zdravljenju z bakteriofagi so potrebne večje količine bakteriofagov, zato smo se med raziskovanjem ukvarjali z vplivom spreminjanja hitrosti redčenja na produktivnost gojenja bakteriofagov v kontinuirnem sistemu. V kontinuirnih sistemih nenehno dovajamo hranila in odvajamo odpadne produkte in celice, zato je volumen v bioreaktorju ves čas konstanten in se v določenem času vzpostavi stacionarno stanje. To smo spremljali z merjenjem optične gostote. Miniaturni kontinuirni sistem je sestavljen iz črpalke in dveh zaporedno povezanih bioreaktorjev »C« in »P« (volumen prvega je 25 ml, volumen drugega je 5 ml). Svež napajalni tok je tekoče LB gojišče, ki ga uvajamo v prvi bioreaktor »C«, kjer poteka gojenje bakterije. V drugem bioreaktorju »P« poteka pomnoževanje bakteriofagov. Kot modelna organizma smo uporabljali bakterijo E. coli K-12 in bakteriofag T4. Izvajali smo dva različna tipa eksperimentov z variabilnim in konstantnim fiziološkim stanjem bakterije. Iztok iz drugega reaktorja in s tem število namnoženih bakteriofagov smo spremljali z vzorčenjem. Vzorce smo nato analizirali in ovrednotili s CFU in PFU analizo. Iz podatkov o koncentraciji bakteriofagov in hitrosti redčenja v drugem bioreaktorju smo izračunali in spreminjali produktivnost. Pokazali smo, da pri optimalni hitrosti redčenja dosežemo maksimalno koncentracijo fagov in produktivnost.

Keywords

bakteriofagi;bakteriofag T4;E. coli K-12;gojenje bakterij;kontinuirna proizvodnja;produktivnost;hitrost redčenja;sistem Cellstat;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [N. Kuzmić]
UDC: 66.098:578.81(043.2)
COBISS: 1538320579 Link will open in a new window
Views: 524
Downloads: 150
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Other data

Secondary language: English
Secondary title: Changes of productivity in continuous production of bacteriophages
Secondary abstract: Bacteriophages (phages) are present almost everywhere around us. Their key role is regulating microbial community in various ecosystems, therefore they are regaining attention as natural antimicrobial agents for potential antibacterial treatments also in human medicine, especially for multi-drug resistant bacteria. Phages are bacterial viruses which are formed during the process of infection and final lysis of bacteria. In medical applications and therapeutics, large amount and higher concentrations of phages are required. Phages are nowadays still being amplified traditionally, on laboratory scale in shaking culture flasks and as batch process in bioreactors on industry level. In our case, we studied the effect of dilution rate on productivity of continuous production of phages in “cellstat” which consists of two connected glass bioreactors »C« and »P« (volume of the first bioreactor was 25 mL and second bioreactor was 5 mL, respectively), run by a single pump. Fresh LB medium was continuously pumped in the first bioreactor »C« where bacteria were continuously growing and then continuously introduced into second bioreactor »P« where multiplication of phages occurred. As a model system we used well-studied phage T4 and Escherichia coli K-12 as a host. Two different sets of experiments where bacterial physiological state was either varied or kept constant were performed. When the steady state was reached, concentration of phages at the outflow of second bioreactor was evaluated by standard plaque assay and average values were obtained. Productivity of continuous production of bacteriophages was calculated from average phage titers and dilution rate in second bioreactor. The results obtained show that there exists an optimal dilution rate when maximal phage concentration and productivity are achieved.
Secondary keywords: bacteriophage T4;E. coli K-12;continuous production;productivity;dilution rate;
Type (COBISS): Master's thesis/paper
Study programme: 1000376
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemijsko inženirstvo
Pages: 59 str.
ID: 11372679