Novel Xylose and Shikimate Transporters Facilitating the Design of a Microbial Consortium as a Chassis for Benzylisoquinoline Alkaloid Production

Abstract

Abstract Plant-sourced aromatic amino acid (AAA) derivatives are a vast group of compounds with broad applications. This study focuses on the development of a yeast consortium for efficient production of (S)-norcoclaurine, the key precursor for benzylisoquinoline alkaloid biosynthesis. A novel xylose-specific transporter insensitive to glucose inhibition enabled the concurrent mixed-sugar utilization in Scheffersomyces stipitis, which played a crucial role in enhancing the flux entering the highly regulated shikimate pathway located upstream of AAA biosynthesis. Two novel quinate permeases isolated from Aspergillus niger facilitated shikimate translocation to the co-cultured Saccharomyces cerevisiae that converted shikimate to (S)-norcoclaurine, resulting in the highest titer (4.2 mg/L) ever reported in literature, nearly 40-fold higher than the best titer from an S. cerevisiae monoculture. Our findings magnify the potential of microbial consortium platforms for the economical de novo synthesis of complex compounds, where pathway modularization and compartmentalization in distinct specialty strains enable effective fine-tuning of long biosynthetic pathways and diminish intermediate buildup, thereby leading to remarkable increases in production.