TY - JOUR
T1 - Synergistic co-utilization of biomass-derived sugars enhances aromatic amino acid production by engineered Escherichia coli
AU - Liu, Arren
AU - Machas, Michael
AU - Mhatre, Apurv
AU - Hajinajaf, Nima
AU - Sarnaik, Aditya
AU - Nichols, Nancy
AU - Frazer, Sarah
AU - Wang, Xuan
AU - Varman, Arul M.
AU - Nielsen, David R.
N1 - Publisher Copyright:
© 2023 Wiley Periodicals LLC.
PY - 2024/2
Y1 - 2024/2
N2 - Efficient co-utilization of mixed sugar feedstocks remains a biomanufacturing challenge, thus motivating ongoing efforts to engineer microbes for improved conversion of glucose−xylose mixtures. This study focuses on enhancing phenylalanine production by engineering Escherichia coli to efficiently co-utilize glucose and xylose. Flux balance analysis identified E4P flux as a bottleneck which could be alleviated by increasing the xylose-to-glucose flux ratio. A mutant copy of the xylose-specific activator (XylR) was then introduced into the phenylalanine-overproducing E. coli NST74, which relieved carbon catabolite repression and enabled efficient glucose−xylose co-utilization. Carbon contribution analysis through 13C-fingerprinting showed a higher preference for xylose in the engineered strain (NST74X), suggesting superior catabolism of xylose relative to glucose. As a result, NST74X produced 1.76 g/L phenylalanine from a model glucose−xylose mixture; a threefold increase over NST74. Then, using biomass-derived sugars, NST74X produced 1.2 g/L phenylalanine, representing a 1.9-fold increase over NST74. Notably, and consistent with the carbon contribution analysis, the xylR* mutation resulted in a fourfold greater maximum rate of xylose consumption without significantly impeding the maximum rate of total sugar consumption (0.87 vs. 0.70 g/L-h). This study presents a novel strategy for enhancing phenylalanine production through the co-utilization of glucose and xylose in aerobic E. coli cultures, and highlights the potential synergistic benefits associated with using substrate mixtures over single substrates when targeting specific products.
AB - Efficient co-utilization of mixed sugar feedstocks remains a biomanufacturing challenge, thus motivating ongoing efforts to engineer microbes for improved conversion of glucose−xylose mixtures. This study focuses on enhancing phenylalanine production by engineering Escherichia coli to efficiently co-utilize glucose and xylose. Flux balance analysis identified E4P flux as a bottleneck which could be alleviated by increasing the xylose-to-glucose flux ratio. A mutant copy of the xylose-specific activator (XylR) was then introduced into the phenylalanine-overproducing E. coli NST74, which relieved carbon catabolite repression and enabled efficient glucose−xylose co-utilization. Carbon contribution analysis through 13C-fingerprinting showed a higher preference for xylose in the engineered strain (NST74X), suggesting superior catabolism of xylose relative to glucose. As a result, NST74X produced 1.76 g/L phenylalanine from a model glucose−xylose mixture; a threefold increase over NST74. Then, using biomass-derived sugars, NST74X produced 1.2 g/L phenylalanine, representing a 1.9-fold increase over NST74. Notably, and consistent with the carbon contribution analysis, the xylR* mutation resulted in a fourfold greater maximum rate of xylose consumption without significantly impeding the maximum rate of total sugar consumption (0.87 vs. 0.70 g/L-h). This study presents a novel strategy for enhancing phenylalanine production through the co-utilization of glucose and xylose in aerobic E. coli cultures, and highlights the potential synergistic benefits associated with using substrate mixtures over single substrates when targeting specific products.
KW - aromatic biochemicals
KW - carbon catabolite repression
KW - corn stover hydrolysate
KW - flux balance analysis
KW - phenylalanine
KW - sugar co-utilization
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U2 - 10.1002/bit.28585
DO - 10.1002/bit.28585
M3 - Article
C2 - 37926950
AN - SCOPUS:85176136942
SN - 0006-3592
VL - 121
SP - 784
EP - 794
JO - Biotechnology and bioengineering
JF - Biotechnology and bioengineering
IS - 2
ER -