TY - JOUR
T1 - Metabolic analyses of Yarrowia lipolytica for biopolymer production reveals roadblocks and strategies for microbial utilizing volatile fatty acids as sustainable feedstocks
AU - Xiao, Zhengyang
AU - Xiong, Xiaochao
AU - Sun, Yufei
AU - Tourang, Masoud
AU - Chen, Shulin
AU - Tang, Yinjie J.
N1 - Publisher Copyright:
© 2024 The Author(s)
PY - 2025/2
Y1 - 2025/2
N2 - This study quantifies metabolic features of engineered Yarrowia lipolytica strains for converting volatile fatty acids (VFAs) into poly-3-hydroxybutyrate (PHB) via 13C-metabolic flux analysis and RNA-Seq. Yarrowia lipolytica is unable to grow with C4 ∼ C6 VFAs due to substrate toxicity, while propionate (C3) metabolism leads to slow growth and minimal PHB production due to enzymatic limitations in substrate assimilation pathways. Acetate is a viable but challenging VFA feedstock. Comparing to glucose, acetate catabolism results in low ATP/ADP ratios, high enzyme usage, substantial CO2 release (>50 % of input carbon), and limited NADPH. Several strategies may overcome these roadblocks: 1) glucose-VFA co-catabolism improves energy charge, alleviates metabolic imbalances, reduces flux rigidity, and lowers the enzyme expression burden; 2) overexpressing acetyl-CoA synthetase and nitrogen limitation increase acetate uptake and PHB synthesis during glucose-acetate co-utilization; and 3) repression of oxidase facilitates fluxes towards PHB synthesis. The results provide insights into efficient utilization of acetate as feedstock.
AB - This study quantifies metabolic features of engineered Yarrowia lipolytica strains for converting volatile fatty acids (VFAs) into poly-3-hydroxybutyrate (PHB) via 13C-metabolic flux analysis and RNA-Seq. Yarrowia lipolytica is unable to grow with C4 ∼ C6 VFAs due to substrate toxicity, while propionate (C3) metabolism leads to slow growth and minimal PHB production due to enzymatic limitations in substrate assimilation pathways. Acetate is a viable but challenging VFA feedstock. Comparing to glucose, acetate catabolism results in low ATP/ADP ratios, high enzyme usage, substantial CO2 release (>50 % of input carbon), and limited NADPH. Several strategies may overcome these roadblocks: 1) glucose-VFA co-catabolism improves energy charge, alleviates metabolic imbalances, reduces flux rigidity, and lowers the enzyme expression burden; 2) overexpressing acetyl-CoA synthetase and nitrogen limitation increase acetate uptake and PHB synthesis during glucose-acetate co-utilization; and 3) repression of oxidase facilitates fluxes towards PHB synthesis. The results provide insights into efficient utilization of acetate as feedstock.
KW - ATP
KW - Co-catabolism
KW - Metabolic flux analysis
KW - PHB
KW - VFA
UR - http://www.scopus.com/inward/record.url?scp=85210022967&partnerID=8YFLogxK
U2 - 10.1016/j.biortech.2024.131855
DO - 10.1016/j.biortech.2024.131855
M3 - Article
C2 - 39580096
AN - SCOPUS:85210022967
SN - 0960-8524
VL - 417
JO - Bioresource Technology
JF - Bioresource Technology
M1 - 131855
ER -