Interfacing microbial styrene production with a biocompatible cyclopropanation reaction

Area of Science:

• Synthetic biology
• Biocatalysis
• Metabolic engineering

Background:

• Integrating non-native chemical reactivity into living systems for small-molecule production remains a significant challenge.
• While progress has been made in developing aqueous-compatible catalysts and in vitro enzyme engineering, combining these with metabolic pathways is underexplored.

Purpose of the Study:

• To develop a biocompatible catalyst for introducing new reactivity into microorganisms.
• To demonstrate the direct synthesis of non-natural small molecules from metabolic feedstocks using a combined chemo- and bio-catalytic approach.

Main Methods:

• A biocompatible iron(III) phthalocyanine catalyst was employed for olefin cyclopropanation.
• Escherichia coli (E. coli) was engineered to produce styrene, a precursor for cyclopropanation.
• Single-vessel fermentations were performed, integrating the catalyst with the engineered microbial metabolism.

Main Results:

• The iron(III) phthalocyanine catalyst demonstrated efficient olefin cyclopropanation in the presence of living E. coli.
• Non-natural phenyl cyclopropanes were successfully synthesized directly from D-glucose in a single fermentation vessel.
• This represents the first successful integration of nonbiological carbene-transfer reactivity with cellular metabolism for small-molecule production.

Conclusions:

• The developed catalyst and integrated process enable the direct production of non-natural compounds from simple sugars within living microorganisms.
• This work opens new avenues for producing valuable chemicals by merging synthetic chemistry with microbial fermentation.
• The approach holds promise for sustainable and efficient biosynthesis of complex molecules.