YIN Mengqi, ZHAO Jianzhi
Terpenoids,natural products formed from isopentenyl diphosphate (IPP)and dimethylallyl diphosphate (DMAPP)as precursors,are almost ubiquitous in all organisms,with medicinal plants being predominant.They find wide applications in pharmaceuticals,food,chemical,and energy industries.The extraction from plants and chemical synthesis are commonly employed methods to obtain terpenoids.However,both methods suffer from drawbacks such as low efficiency,unstable quality,and high costs.These limitations clearly cannot meet the increasing demand for terpenoids.With the rapid development of synthetic biology techniques,significant progress has been made in engineering microorganisms for the synthesis of terpenoids,particularly yeast cells.Yeast cells,owing to their similar structure to plant cells and mature genetic manipulation systems,have been utilized for the synthesis of various terpenoids,gradually showcasing the advantages of biosynthetic approaches.This article reviews the progress of metabolic engineering for efficient synthesis of important terpenoids using two model yeasts,Saccharomyces cerevisiae and Yarrowia lipolytica,as examples.Specifically,it summarizes various strategies for metabolic engineering,including the screening and expression of highly active terpenoid synthases,the supply and efficient utilization of key precursor acetyl-CoA,as well as strategies for enhancing the synthesis flux of direct precursors,IPP and DMAPP,while minimizing their consumption.Finally,the article concludes with a summary and outlook on the opportunities and challenges faced by yeast-based synthesis of terpenoids.