Matematičko modeliranje biosinteze mcl-PHA u stanicama Pseudomonas citronellolis I Pseudomonas chlororaphis

master's thesis

• Title (english): Mathematical modeling of mcl-PHA biosynthesis by Pseudomonas citronellolis and Pseudomonas chlororaphis
• Author: Veronika Gunjević
• Mentor: Predrag Horvat (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2017-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Polihidroksialkanoati srednje duljine lanca (mcl-PHA) privlače sve veću pozornost kao biološki proizvedena i biorazgradiva „zelena plastika“. Za proizvodnju mcl-PHA korišteni su kao proizvodni mikroorganizmi bakterije Pseudomonas chlororaphis i P. citronellolis, a kao sirovina zasićeni metilni esteri masnih kiselina iz biodizela. U svrhu optimizacije proizvodnje mcl-PHA, detekcije određenih nepravilnosti prilikom provođenja procesa (režima pritoka izvora C i N) te u svrhu boljeg razumjevanja kinetike rasta navedenih mikroorganizama, izrađeni su formalno kinetički matematički modeli zasnovani na eksperimentalnim podacima. Modeli su temeljeni na strategiji „dva odjeljka“ biomase (biokatalitički dio i rezervne tvari) i na Leudeking-Piret odnosu između specifične brzine rasta i biosinteze proizvoda. Za modeliranje i simulacije korišten je program Berkeley Madonna. Matematički modeli se djelomično slažu s eksperimentalnim podacima. Neslaganje postoji za varijablu koncentracija rezidualne biomase (biokatalitički aktivne komponente) za period limitacije rasta izvorom dušika, a vidljivo je kao prisutan rast rezidualne biomase u dijelu uzgoja kad u podlozi nije bilo iskoristivog izvora dušika. Takav rezultat upućuje na potrebnu korekciju metode određivanja koncentracije rezidualne biomase.

Abstract (english)

Medium chain length polyhydroxyalkanoate (mcl-PHA) attract increasing attention as biobased and biodegradable „green plastics“. Pseudomonas chlororaphis and P. citronellolis were selected as production strains for mcl-PHA production from saturated fatty acids methyl esters (excluded from biodiesel). For the optimization of the mcl-PHA production process, for detection of irregularities during the process and for better understanding of the growth kinetics and mcl-PHA biosynthesis, formal kinetic mathematical models (based on experimental data) were established. The models were based on the „two main biomass compartments strategy“ (biocatalitycally active part and storage materials) as well as on the Leudeking-Piret relation between the specific growth and PHA production rate respectively. For modelling and simulation purposes Berkeley Madonna software was used. Mathematical models partially match the experimental data. There was a disagreement between the experimental concentration of the residual biomass and the simulated values in the nitrogen-limited growth phase. This disagreement is evident as the growth of residual biomass in the cultivation phase when there wasn't utilizable nitrogen source. Such results indicate the necessary correction of the biomass concentration determination method.

• Keywords: srednjelančani PHA; matematičko modeliranje; formalno kinetički model; Pseudomonas chlororaphis; Pseudomonas citronellolis
• Keywords (english): mcl-PHA; mathematical modelling; formal kinetic model; Pseudomonas chlororaphis; Pseudomonas citronellolis
• Language: croatian
• URN:NBN: urn:nbn:hr:159:167716
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-11-23 09:28:21