Establishing CO2 fixation pathways in Methylobacterium extorquens

Converting a heterotrophic organism into an autotrophic one is one of the long standing goals of synthetic biology. We focus on Methylobacterium extorquens AM1 as a model organism for implementing autotrophy due to easy separation of energy generation and carbon assimilation. The Calvin‑Benson‑Bassham (CBB) cycle was introduced into M. extorquens leading to a growth phenotype but continuous stable growth was not achieved¹. Metabolic ¹³C-tracer analysis demonstrated the functional operation of the synthetic CBB cycle in this strain. Further engineering has been done to establish laboratory evolution conditions which will yield a stable synthetic autotrophic organism.

¹Schada von Borzyskowski, Carrillo et al. An engineered Calvin-Benson-Bassham cycle for carbon dioxide fixation in Methylobacterium extorquens AM1. Metab. Eng. 47, 423–433 (2018).