Engineering Streptomyces for Efficient Terpenoid Production.

Area of Science:

• Metabolic Engineering
• Synthetic Biology
• Natural Product Biosynthesis

Background:

• Terpenoids possess significant agricultural and therapeutic potential but face production challenges due to low natural abundance and complex oxidative tailoring.
• Conventional microbial hosts often lack the necessary enzymatic machinery, particularly cytochrome P450s, for efficient production of complex terpenoid derivatives.

Purpose of the Study:

• To develop alternative microbial chassis for scalable production of structurally complex terpenoids.
• To leverage the biosynthetic capabilities of Streptomyces for enhanced terpenoid synthesis and oxidative tailoring.

Main Methods:

• Engineered two Streptomyces hosts as alternative production chassis.
• Employed the EcoMine strategy to identify and assemble a TriMEP cassette with rate-limiting MEP pathway genes.
• Optimized culture medium and utilized strong constitutive promoters for gene expression.

Main Results:

• Achieved high-level production of four terpenoids, including three oxidized products, in shake-flask cultures.
• Reported yields include (-)-epi-α-bisabolol (237 ± 14 mg/L), ent-(13Z)-isocupressic acid (173 ± 14 mg/L), ent-(13E)-isocupressic acid (209 ± 20 mg/L), and ent-atiserenoic acid (325 ± 17 mg/L).
• Demonstrated successful cytochrome P450-mediated oxidative tailoring within the engineered Streptomyces hosts.

Conclusions:

• Streptomyces serves as a robust and underutilized microbial chassis for the sustainable production of complex terpenoids.
• The developed metabolic engineering strategies enable access to valuable oxidized terpenoid derivatives.