20.500.12556/RUL-163160 Povezava med raztopljenim kisikom, rastjo in izražanjem surfaktinskega operona v stresani kulturi bakterije Bacillus subtilis Relationship between dissolved oxygen, growth and surfactin operon expression in shaken culture of Bacillus subtilis V magistrskem delu smo preučevali povezanost med kisikom, izražanjem surfaktinskega operona in optično gostoto v stresani kulturi bakterije Bacillus subtilis. Uspešno smo sestavili aparaturo za hkratno gojenje, vzorčenje in spremljanje raztopljenega kisika. Izražanju surfaktinskega operona smo sledili posredno preko genskega konstrukta srfA-lacZ. Rezultati kažejo, da raztopljeni kisik v splošnem pada z naraščanjem celične gostote, vendar se ob koncu eksponentne faze rasti pojavljajo nihanja v koncentraciji raztopljenega kisika, ki mu sledi nihanje v izražanju surfaktinskega operona. Povišana koncentracija zunajcelične β-galaktozidaze, odsotnost oz. spremenjeno nihanje v koncentraciji kisika pri mutantah okvarjenih v genih za encime odgovorne za avtolizo, ΔlytABC, kažejo da je v lokalno nihanje koncentracije kisika vpletena celična liza. Običajno je, tekom rasti, izražanje surfaktinskega operona pozitivno povezano s celično gostoto in negativno z raztopljenim kisikom. V stresani kulturi je odnos med celično gostoto in raztopljenim kisikom v splošnem v negativni linearni korelaciji. In the master's thesis, we investigated the relationship between dissolved oxygen, surfactin operon expression, and optical density in shaken cultures of Bacillus subtilis. We have successfully assembled a device for simultaneous cultivation, sampling, and monitoring of dissolved oxygen. Surfactin operon expression was indirectly monitored using the srfA-lacZ genetic construct. The results show that dissolved oxygen generally decreases with increasing cell density; however, at the end of the exponential growth phase, fluctuations in dissolved oxygen concentration occur, followed by fluctuations in surfactin operon expression. The increased extracellular β-galactosidase concentrations, oxygen availability, and altered oxygen concentration fluctuations in mutants deficient in ΔlytABC, genes encoding enzymes responsible for autolysis, suggest that cell lysis is involved in local oxygen concentration fluctuations. Overall, during growth, the expression of the surfactin operon is positively correlated with cell density and negatively correlated with dissolved oxygen. In shaken cultures, the relationship between cell density and dissolved oxygen is generally in a negatively linearly related. Bacillus subtilis raztopljeni kisik surfaktin stresana kultura Bacillus subtilis dissolved oxygen surfactin shake flask culture true false false [S. Bricman] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2024-10-03 07:16:31 2024-10-03 07:16:35 2024-10-09 13:51:35 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579.22/.26:579.852.11 248169 210876163 44295.pdf 44295.pdf 1 6331C8FB727EDCA9BE28F72D149BB50C 6c54968c60acb5f7327d3f5fbcfa73e898a33d214c0e0f03c62580bdedc94212 80335716-8146-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=192674 Biotehniška fakulteta 0 0 0