Vibha Shukla, Virendra Shukla, Shweta Rawat, Vandana Singh, Suresh Chandra Phulara
Terpenoids (isoprenoids) constitute one of the largest and most structurally diverse families of natural products with application ranging from flavors, pharmaceuticals to biofuels. Conventional extraction from plants is often limited by low yields, seasonal variability, and environmental constraints; whereas, chemical synthesis requires toxic chemicals and energy-intensive processes. Consequently, microbial cell factories have emerged as sustainable and industrially scalable alternatives for terpenoid biosynthesis. Different microorganisms possess distinct physiological and metabolic advantages, including efficient precursor supply, tolerance to toxic products, internal storage for hydrophobic compounds, utilization of renewable carbon sources, and compatibility with complex biosynthetic pathways. Furthermore, several microbial hosts have strains with Generally Recognized as Safe (GRAS) status, making them attractive candidates for food and nutraceutical applications, although their regulatory acceptance ultimately depends on the production strain, genetic modifications, manufacturing process, product, and intended use. In addition, photosynthetic cyanobacteria offer a promising platform for direct conversion of CO2 into terpenoids, providing opportunities for more resource-efficient and sustainable biomanufacturing. Therefore, strategic host selection is a crucial step in designing efficient microbial platforms for terpenoid production. The present review provides a host-centric perspective by comparing conventional and emerging microbial cell factories, highlighting their physiological strengths, product spectrum, industrial applicability, and strategic considerations for sustainable and application-specific terpenoid biomanufacturing.