Overcoming barriers to medium-chain fatty alcohol production.

Medium-chain fatty alcohols (FaOHs) are aliphatic primary alcohols containing six to twelve carbons that are widely used in materials, pharmaceuticals, and cosmetics. Microbial biosynthesis has been touted as a route to less-abundant chain-length molecules and as a sustainable alternative to current petrochemical processes. Several metabolic engineering strategies for producing FaOHs have been demonstrated in the literature, yet processes continue to suffer from poor selectivity and FaOH toxicity, leading to reduced titers, rates, and yields of the desired compounds. This opinion examines the current state of microbial FaOH biosynthesis, summarizing engineering efforts to tailor selectivity and improve product tolerance by implementing engineering strategies that circumvent or overcome FaOH toxicity.