Genomes of rumen bacteria encode atypical pathways for fermenting hexoses to short-chain fatty acids
Item Type Article
Authors Hackmann, Timothy J.;Ngugi, David;Firkins, Jeffrey L.;Tao, Junyi Citation Hackmann TJ, Ngugi DK, Firkins JL, Tao J (2017) Genomes of
rumen bacteria encode atypical pathways for fermenting hexoses to short-chain fatty acids. Environmental Microbiology. Available:
http://dx.doi.org/10.1111/1462-2920.13929.
Eprint version Post-print
DOI 10.1111/1462-2920.13929
Publisher Wiley
Journal Environmental Microbiology
Rights This is the peer reviewed version of the following article:
Genomes of rumen bacteria encode atypical pathways for fermenting hexoses to short-chain fatty acids, which has been published in final form at http://doi.org/10.1111/1462-2920.13929.
This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Download date 2023-11-01 05:41:09
Link to Item http://hdl.handle.net/10754/625456
Fig. S2. Pathway for fermentation of glucose to butyrate and acetate. (A) Typical pathway, which does not involve Ech. (B) Atypical pathway, which involves Ech and found in some rumen bacteria (Butyrivibrio hungatei JK615, Butyrivibrio proteoclasticus B316, Pseudobutyrivibrio xylanivorans Mz 5). The coefficient x is the number of acetate formed (consumed) and varies by bacterium (see Supporting Information Table S2). It is assumed that another reaction (e.g., that catalyzed by an antiporter) balances Na+ and H+. Panel A is adapted from Louis and Flint (2017), and panel B is adapted from Hackmann and Firkins (2015). Panel A includes reactions shown in Supporting Information Fig. S1A, E, J, L, U, X, Y, AD, AE, AF, AY, BC, and BD. Panel B includes reactions shown in Supporting Information Fig. S1A, E, J, L, U, X, Y, AD, AE, AF, BB, BC, and BD. Reactions: 1. pyruvate:ferredoxin oxidoreductase; 2.
acetyl-CoA C-acetyltransferase; 3. 3-hydroxybutyryl-CoA dehydrogenase; 4. enoyl-CoA hydratase; 5. butyryl-CoA dehydrogenase; 6. ferredoxin hydrogenase, cytoplasmic; 7. Rnf; 8.
ATP synthase; 9. Ech hydrogenase. Abbreviations: Fdox= oxidized ferredoxin, Fdred = reduced ferredoxin, NADox= oxidized NAD, and NADred= reduced NAD.
Figure S2
1
2 Pyruvate
2 Fdox 2 CoA
1
2 Fdred 2 CO2
x Acetate x Acetyl-CoA x ADP +x Pi
x ATP x CoA
(2 - x) Acetyl-CoA
(1 - x/2) Butanoyl-CoA 2
(1 + x/2) CoA (1 - x/2) Acetoacetyl-CoA (1 - x/2) NADred
3 (1 - x/2) NADox
(1 - x/2) (S)-3-Hydroxybutanoyl-CoA
4
(1 - x/2) H2O (1 + x/2) Crotonoyl-CoA (1 - x/2) (Fdox+ 2 NADred)
5 (1 - x/2) (Fdred+ 2 NADox)
(1 - x/2) (ADP +Pi)
(1 - x/2) ATP (1 - x/2) CoA (1 - x/2) Butyrate
1 1 Glucose 2 ADP + 2 Pi +2 NADox
2 ATP + 2 NADred 2 H2O
(2 - 3x) H+ (2 - 3x) H+ (2 - 3x)/4× (ADP +Pi)
(2 - 3x)/4× (ATP +H2O) 8
in out
(2 - 3x) Na+ (2 - 3x) Na+ (1 - 3/2 x) (Fdred+ NADox)
(1 - 3/2 x) (Fdox+ NADred) 7 (2 + x) Fdred
6
(2 + x) Fdox (2 + x) H2 (A)
Figure S2
2
2 Pyruvate
2 Fdox 2 CoA
1
2 Fdred 2 CO2
x Acetate x Acetyl-CoA x ADP +x Pi
x ATP x CoA
(2 - x) Acetyl-CoA
(1 - x/2) Butanoyl-CoA 2
(1 + x/2) CoA (1 - x/2) Acetoacetyl-CoA (1 - x/2) NADred
3 (1 - x/2) NADox
(1 - x/2) (S)-3-Hydroxybutanoyl-CoA
4
(1 - x/2) H2O (1 + x/2) Crotonoyl-CoA (1 - x/2) (Fdox+ 2 NADred)
5 (1 - x/2) (Fdred+ 2 NADox)
(1 - x/2) (ADP +Pi)
(1 - x/2) ATP (1 - x/2) CoA (1 - x/2) Butyrate
1 1 Glucose 2 ADP + 2 Pi +2 NADox
2 ATP + 2 NADred 2 H2O
(6 - x) H+ (6 - x) H+ (6 - x)/4× (ADP +Pi)
(6 - x)/4× (ATP +H2O) 8
in out
(2 - 3x) Na+ (2 - 3x) Na+ (1 - 3/2 x) (Fdred+ NADox)
(1 - 3/2 x) (Fdox+ NADred) 7
(4 + 2x) H+ (4 + 2x) H+ (2 + x) Fdred
(2 + x) Fdox 9
(2 + x) H2 (B)
Figure S2
3