Razvoj mikropretočnih sistemov za gojenje biofilmov bakterije Bacillus subtilis ; Development of microfluidic devices for Bacillus subtilis biofilm cultivation

Vitamin B2 (riboflavin) je primarni metabolit, ki ga gensko spremenjeni sevi Bacillus subtilis proizvajajo v industrijskih količinah. V stresanih kulturah smo preizkusili različna gojišča, da smo dobili tako, v katerem je imel zbrani proizvodni organizem najvišjo produktivnost. Za izboljšanje razumevanja rasti B. subtilis in proizvodnje riboflavina smo razvili mikropretočni reaktor za gojenje biofilmov. V tem reaktorju smo izvedli teste prenosa kisika, da smo potrdili, da je reaktor primeren za gojenje aerobnih mikroorganizmov. Biofilme B. subtilis smo gojili pri različnih pretokih gojišča in različnih geometrijah kanalčka. Ugotovili smo, da je za tvorbo stabilnih biofilmov potreben dovolj hiter pretok gojišča, in sicer vsaj 1 μl/min. Biofilme smo v mikropretočnem reaktorju gojili v različnih gojiščih in z dovajanjem različnih količin kisika. Ugotovili smo, da količina razpoložljivega kisika močno vpliva na tvorbo in razvoj biofilma ter njegove morfološke karakteristike. V razvitem mikroreaktorskem sistemu zaradi kratkih zadrževalnih časov bakterija ni proizvedla zadostnih količin riboflavina, da bi ga lahko spremljali v integriranem analiznem sistemu. ; Vitamin B2 (riboflavin) is the primary metabolite produced in industrial quantities by genetically modified strains of Bacillus subtilis. Different media were tested in shake cultures to obtain the one with the highest productivity of the selected production organism. To improve the understanding of B. subtilis growth and riboflavin production, we have developed a microfluidic reactor for biofilm cultivation. In this reactor, oxygen transfer tests were carried out to confirm that the reactor is suitable for the cultivation of aerobic microorganisms. Biofilms of B. subtilis were grown at different flow rates and different channel geometries. We found that a sufficiently fast medium flow rate of at least 1 μl/min was required for the formation of stable biofilms. Biofilms were grown in the microfluidic reactor in different media and with different amounts of ...