Using Engineered Escherichia coli to Synthesize Squalene with Optimized Manipulation of Squalene Synthase and Mevalonate Pathway

Squalene is the metabolic precursor of sterols and naturally synthesized in the deep-dea shark liver and human sebum. The utilization of squalene is wide such as food, cosmetical, and pharmaceutical industries. This experiment used engineered Escherichia coli to construct the gene circuit for the biosynthesis of squalene. Human squalene synthase (hSQS) efficiently catalyzes the synthesis of squalene. Also, mevalonate (MVA) pathway would increase the yield of the precursor of squalene, farnesyl diphosphate, which then increased the yield of squalene. Meanwhile, the regulation of MVA pathway via different inducer IPTG concentrations and creation of selection pressure by antibiotics were investigated.