Novel fermentation processes for manufacturing plant natural products.

Microbial production of plant natural products (PNPs), such as terpenoids, flavonoids from renewable carbohydrate feedstocks offers sustainable and economically attractive alternatives to their petroleum-based production. Rapid development of metabolic engineering and synthetic biology of microorganisms shows many advantages to replace the current extraction of these useful high price chemicals from plants. Although few of them were actually applied on a large scale for PNPs production, continuous research on these high-price chemicals and the rapid growing global market of them, show the promising future for the production of these PNPs by microorganisms with a more economic and environmental friendly way. Introduction of novel pathways and optimization of the native cellular processes by metabolic engineering of microorganisms for PNPs production are rapidly expanding its range of cell-factory applications. Here we review recent progress in metabolic engineering of microorganisms for the production of PNPs. Besides, factors restricting the yield improvement and application of lab-scale achievements to industrial applications have also been discussed.