- Liu, Di;
- Hwang, Hee Jin;
- Otoupal, Peter B;
- Geiselman, Gina M;
- Kim, Joonhoon;
- Pomraning, Kyle R;
- Kim, Young-Mo;
- Munoz, Nathalie;
- Nicora, Carrie D;
- Gao, Yuqian;
- Burnum-Johnson, Kristin E;
- Jacobson, Oslo;
- Coradetti, Samuel;
- Kim, Jinho;
- Deng, Shuang;
- Dai, Ziyu;
- Prahl, Jan-Philip;
- Tanjore, Deepti;
- Lee, Taek Soon;
- Magnuson, Jon K;
- Gladden, John M
Microbial production of valuable bioproducts is a promising route towards green and sustainable manufacturing. The oleaginous yeast, Rhodosporidium toruloides, has emerged as an attractive host for the production of biofuels and bioproducts from lignocellulosic hydrolysates. 3-hydroxypropionic acid (3HP) is an attractive platform molecule that can be used to produce a wide range of commodity chemicals. This study focuses on establishing and optimizing the production of 3HP in R. toruloides. As R. toruloides naturally has a high metabolic flux towards malonyl-CoA, we exploited this pathway to produce 3HP. Upon finding the yeast capable of catabolizing 3HP, we then implemented functional genomics and metabolomic analysis to identify the catabolic pathways. Deletion of a putative malonate semialdehyde dehydrogenase gene encoding an oxidative 3HP pathway was found to significantly reduce 3HP degradation. We further explored monocarboxylate transporters to promote 3HP transport and identified a novel 3HP transporter in Aspergillus pseudoterreus by RNA-seq and proteomics. Combining these engineering efforts with media optimization in a fed-batch fermentation resulted in 45.4 g/L 3HP production. This represents one of the highest 3HP titers reported in yeast from lignocellulosic feedstocks. This work establishes R. toruloides as a host for 3HP production from lignocellulosic hydrolysate at high titers, and paves the way for further strain and process optimization towards enabling industrial production of 3HP in the future.