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| Author(s): |
Mateus Schreiner Garcez Lopes
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2010-06-15 |
| Examining board members: |
Luiziana Ferreira da Silva;
Flavio Alterthum;
Shaker Chuck Farah;
Rosane Aparecida Moniz Piccoli;
Jose Geraldo da Cruz Pradella
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| Advisor: | Luiziana Ferreira da Silva |
| Abstract | |
The aim of this thesis is to produce poly3-hydroxybutyrate (P3HB) and poli-3-hidroxibutirate-co-3-hydroxyvalerate (PHB-co-3HV), biodegradable polymers, using hemicellulosic hydrolysate, rich in xylose, from sugarcane bagasse. Metabolic flux analysis in silico of xylose metabolism indicated that, though metabolism redirection is possible to increase P3HB yield from 0.25 g g-1 to 0.40 g g-1. It was observed simultaneous consumption of sugars and reduction of time necessary to exhaust of all sugars in the media culture in mutants with catabolite repression partially abolished. However, differences in carbon flux resulted in lower growth and P3HB production in comparison to the parental strain. A bioprospecting program selected Burkholderia sp. F24, in experiments in bioreactor it reached 25.04 g l-1, 49.31% of P3HB accumulation of the dry cell mass and 0.28 g l-1 h-1 of productivity. Moreover, it was possible to modulate to molar fraction of 3HV in PHB-co-3HV biosyntheses with Burkholderia sp. F24 using xylose and levulinic acid. (AU) | |