Photosynthetic Bioplastics Production with Cyanobacteria by Coupled Growth-Production Mutants

LASRY TESTA, R.; ESTRADA, V.; DELPINO, C.; DIAZ, M. S.

Computer Aided Chemical Engineering

Elsevier

Año: 2021

1570-7946

In this work, we study PHB direct production (without a heterotrophic step) usingSynechocystis sp PCC 6803 with a Systems Metabolic Engineering approach. Weconsider a GEnome-scale Model (GEM) of the cyanobacteria, developed in previouswork, and use it to couple growth with PHB production by finding genetic interventions(knock-outs) that make PHB production essential for growth. This is achieved by abilevel-programming problem, in which the knock-outs are represented by binaryvariables related to the genes of the GEM. After reformulation based on duality theory, aMixed Integer Linear Programming (MILP) problem is obtained and solved in GAMS. Amutant that completely couples biopolymer production with growth in Synechocystis isobtained, and its flux distributions under exponential growth conditions are analysed byFlux Balance Analysis (FBA). Numerical results provide useful insights on sustainablephotosynthetic bioplastics production with cyanobacteria.