20.500.12556/RUL-188214 Primerjava dinamike izrezovanja profaga v različnih gostiteljskih sevih Bacillus subtilis ter njena korelacija z dinamiko sporulacije in stopnjo disperzibilnosti spor Comparison of prophage excision dynamics in different host strains of Bacillus subtilis and its correlation with sporulation dynamics and spore dispersibility Temperatni fag SPβ z regulirano integracijo in ekscizijo svojega genoma (profaga) iz genoma gostiteljske bakterije uravnava izražanje gena spsM bakterije Bacillus subtilis. Produkt gena spsM sodeluje pri tvorbi skorje spore in prispeva k disperzibilnosti spor v vodnem okolju. Do ekscizije profaga SPβ iz gena spsM prihaja izključno v materinski celici spore, pri čemer pri procesu sodeluje produkt gena sprB, katerega izražanje je regulirano v okviru sporulacijskega programa. Ker je ekscizija tesno povezana s potekom sporulacije bakterije Bacillus subtilis in ker se dinamika sporulacije med sevi Bacillus subtilis ter gojišči razlikuje, je bil cilj našega dela preučiti časovno dinamiko ekscizije profaga SPβ v različnih sevih in pogojih gojenja. V tem magistrskem delu smo ugotovili, da je ekscizija profaga pri laboratorijskem sevu 168 v bogatem gojišču časovno zakasnjena v primerjavi z naravnim izolatom, medtem ko v ionsko bogatem sporulacijskem gojišču NSM razlik v časovni dinamiki ekscizije profaga med sevoma nismo opazili. Podoben vzorec smo zaznali tudi pri dinamiki sporulacije, saj je bil začetek sporulacijskega programa v gojišču LB pri laboratorijskem sevu zakasnjen, v gojišču NSM pa je potekal bolj usklajeno med sevoma. Rezultati tako nakazujejo, da sestava gojišča pomembno vpliva na časovni potek sporulacije. Hkrati smo ugotovili, da mutacijsko onemogočena ekscizija profaga SPβ ne vpliva neposredno na časovni potek aktivacije programa sporulacije. Naši rezultati nakazujejo, da sta ekscizija profaga SPβ in sporulacija razvojno usklajena procesa, na katera pomembno vplivata genetsko ozadje gostitelja in okoljski pogoji. Raziskava tako prispeva k boljšemu razumevanju vloge temperatnih fagov pri regulaciji razvojnih procesov bakterij. Temperate phage SPβ regulates the expression of the spsM gene in Bacillus subtilis through precisely controlled integration and excision. The spsM gene is involved in the formation of the spore crust and contributes to the dispersibility of spores in aquatic environments. Excision of the SPβ prophage from the spsM gene occurs exclusively in the spore mother cell and involves the sprB gene product, whose expression is associated with the sporulation program. Previous studies have shown that excision of the SPβ prophage is closely linked to the sporulation process in the bacterium Bacillus subtilis. Since sporulation dynamics differ between Bacillus subtilis strains and growth media, we investigated the dynamics of prophage excision in different Bacillus subtilis strains under different cultivation conditions. In this master's thesis we found that excision of the prophage in the laboratory strain 168 was delayed in LB medium compared with the natural isolate, whereas no such differences in the dynamics of prophage excision between the two strains were observed in the sporulation medium NSM. A similar pattern was observed in sporulation dynamics. The initiation of sporulation in LB medium was delayed in the laboratory strain, whereas in NSM medium the dynamics were more synchronised between strains. These results suggest that the composition of the growth medium plays an important role in determining sporulation timing. We found that mutationally preventing SPβ prophage excision does not directly affect the timing of sporulation initiation. Our results indicate that SPβ prophage excision and sporulation are developmentally coordinated processes that are strongly influenced by the genetic background of the host and environmental conditions. This study contributes to a better understanding of the role of temperate phages in the regulation of bacterial developmental processes. temperatni fag SPβ Bacillus subtilis ekscizija profaga sporulacija disperzibilnost spor temperate phage SPβ Bacillus subtilis prophage excision sporulation spore dispersibility true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-09-19 08:16:57 2026-09-19 08:16:59 2026-09-23 09:43:46 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 290076 292109827 63053.pdf 63053.pdf 1 197613C6A2AA827CD0A7C45FFC19D99F 3d598b09a1f2bbfe522872ff280a1a4e77b23ba231cb676c3ed884be90b044c6 ab2ebc67-b3f1-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=248243 Biotehniška fakulteta 0 0 0