Increased CO2 fixation enables high carbon-yield production of 3-hydroxypropionic acid in yeast
Ning Qin, Lingyun Li, Xiaozhen Wan, Xu Ji, Yu Chen, Chaokun Li, Ping Liu, Yijie Zhang, Weijie Yang, Junfeng Jiang, Jianye Xia, Shuobo Shi, Tianwei Tan, Jens Nielsen, Yun Chen, Zihe Liu, Yun Chen, Zihe Liu
Abstract
Abstract CO 2 fixation plays a key role to make biobased production cost competitive. Here, we use 3-hydroxypropionic acid (3-HP) to showcase how CO 2 fixation enables approaching theoretical-yield production. Using genome-scale metabolic models to calculate the production envelope, we demonstrate that the provision of bicarbonate, formed from CO 2 , restricts previous attempts for high yield production of 3-HP. We thus develop multiple strategies for bicarbonate uptake, including the identification of Sul1 as a potential bicarbonate transporter, domain swapping of malonyl-CoA reductase, identification of Esbp6 as a potential 3-HP exporter, and deletion of Uga1 to prevent 3-HP degradation. The combined rational engineering increases 3-HP production from 0.14 g/L to 11.25 g/L in shake flask using 20 g/L glucose, approaching the maximum theoretical yield with concurrent biomass formation. The engineered yeast forms the basis for commercialization of bio-acrylic acid, while our CO 2 fixation strategies pave the way for CO 2 being used as the sole carbon source.