FURI | Fall 2025

Improving L-serine Availability for Monoethanolamine Production via CRISPRi Mediated Repression of Downstream Amino Acid Synthesis

Monoethanolamine (MEA) is a compound capable of post-combustion CO₂ capture. Engineering bioproduction of MEA from serine has been achieved in Escherichia coli before but is limited by diversion of serine to glycine and cysteine synthesis via enzymes glyA and cysE. Gene knockout can combat this diversion but forces an auxotrophy, requiring costly media supplementation. Alternatively, CRISPRi can achieve tunable repression by blocking transcription of glyA and cysE without altering the genome sequence. By modulating CRISPRi in an E. coli strain that produces monoethanolamine from serine, repression levels that maximize serine availability while minimizing auxotrophy generation can be identified.