Anais do Simpósio Nacional de Bioprocessos
XXII National Bioprocesses Symposium (SINAFERM) XIII Enzymatic Hydrolysis of Biomass Symposium (SHEB)

The Entner-Doudoroff (ED) pathway is a fundamental route in the genus Pseudomonas and it usually operates in a linear mode. Studies with labeling substrates indicated that the pathway can also operate in a cyclic mode. Pseudomonas aeruginosa LFM634 is able to produce simultaneously Polyhydroxyalkanoates (PHA) and Rhamnolipids in non-growing conditions, and it has NADPH as cofactor for the biosynthesis. In this work, we propose to estimate the flux through the cyclic mode of ED pathway in P. aeruginosa LFM634 in non-growing conditions. A computational tool was developed in MATLAB platform that performs 13C-MFA. The tool was applied to perform a design of optimal labeling experiments in order to select a glucose labeling pattern. The simulations indicated two parallel labeling experiments with [6-13C]glucose and [U-13C]glucose as tracers. The experiments were performed in shake flasks and the labeling pattern of monomers in PHA and hydroxyalkanoiloxy-alkanoate were measured by GC-MS. The estimation procedure was then performed and indicated that the glyceraldehyde-3-phosphate is preferentially recycled through the ED cycle. This cyclicity increases the flux of the enzyme Glucose-6-P-1-dehydrogenase that supply NADPH cofactor to the cell. P. aeruginosa LFM634 possibly uses the ED cycle to regulate the generation of this cofactor.