Elucidating redox balance shift in Scheffersomyces stipitis’ fermentative metabolism using a modified genome-scale metabolic model

Table 5 Reactions that contribute significantly to shift in redox balance

Role	Reaction	Reaction equation	Flux change^a	Match TPM trend
NADH production	GAPD	−1 nad[c] +−1 pi[c] +−1 g3p[c] ⟷ 1 h[c]+1 nadh[c]+1 13dpg[c]	0.585	Yes
NADH production	XDH	−1 h[c] +−1 nadh[c] +−1 xylu-D[c] ⟷ 1 nad[c]+1 xylt[c]	0.112	Yes
NADH consumption	ALCDH	−1 etoh[c] +−1 nad[c] ⟷ 1 h[c]+1 acald[c]+1 nadh[c]	0.746	Yes
	NADHDH	−1 h[c] +−1 nadh[c] +−1 q6[m] ⟶ 1 nad[c]+1 q6h2[m]	− 2.294	Yes
	XYLR1	−1 h[c] +−1 nadh[c] +−1 xyl-D[c] ⟶ 1 nad[c]+1 xylt[c]	1.950	N/A^b
	PYRC	−1 h[c] +−1 nadh[c] +−1 glu-L[c] ⟷ 2 h2o[c]+1 nad[c]+1 1pyr5c[c]	0.282	No
NADPH production	G6PDH	−1 nadp[c] +−1 g6p[c] ⟶ 1 h[c]+1 nadph[c]+1 6pgl[c]	− 0.892	Yes
NADPH production	GND	−1 nadp[c] +−1 6pgc[c] ⟶ 1 nadph[c]+1 co2[c]+1 ru5p-D[c]	− 0.892	Yes
NADPH consumption	XYLR2	−1 h[c] +−1 nadph[c] +−1 xyl-D[c] ⟶ 1 nadp[c]+1 xylt[c]	− 1.950	N/A^b
NADPH consumption	P5CR	−2 h[c] +−1 nadph[c] +−1 1pyr5c[c] ⟶ 1 nadp[c]+1 pro-L[c]	0.282	No
Q6H2 production	NADHDH	−1 h[c] +−1 nadh[c] +−1 q6[m] ⟶ 1 nad[c]+1 q6h2[m]	− 2.294	Yes
Q6H2 consumption	CYOR_u6m	−2 h[m] +−1 q6h2[m] +−2 ficytc[m] ⟶ 4 h[c]+1 q6[m]+2 focytc[m]	− 1.788	Yes
ATP production	ATPSm	−1 adp[m] +−1 pi[m] +−4 h[c] ⟶ 1 atp[m]+1 h2o[m]+4 h[m]	− 1.793	Yes

^aFlux change values given in mmol/gCDW/h
^bThe gene for xylose reductase is the same for both the NAD and NADP dependent routes

ISSN: 1475-2859