. 2017 Dec 13;7:17540. doi: 10.1038/s41598-017-17345-7

Table 1.

Representation of other C1 carbon fixation pathways in the enumerated set.

Pathway	rTCA Cycle	Calvin-Benson-Bassham Cycle	Wood-Ljungdahl Pathway	Dicarboxylate/4-Hydroxy butyrate Cycle	3-Hydroxy propionate Bicycle	3-Hydroxy propionate/ 4- Hydroxy butyrate Cycle
Number of Intermediates	11	9	4	12	13	12
Intermediates Enumerated	11	3	3	6	9	5
Compounds Excluded	None	Erythrose¹	Methanol¹	Enol pyruvate³	Propionic acid^1,4	Acrylic acid⁴
		Ribose¹		Succinic semialdehyde^1,4	Methylmalic acid¹	Propionic acid^1,4
		Ribulose¹		Crotonic acid^1,4	Mesaconic acid⁴	Crotonic acid^1,4
		Xylulose¹		Acetoacetic acid^1,4	Citramalic acid¹	Acetoacetic acid^1,4
		Fructose¹		3-Hydroxy butyric acid^1,4		Succinic semialdehyde^1,4
		Sedoheptulose^1,2		4-Hydroxy butyric acid^1,4		4-Hydroxybutyric acid^1,4
						4-Hydroxy butyric acid^1,4

The reasons for their exclusion are given as superscripts in the table and annotated here: 1. H/O ratio violation; 2. C atom number violation; 3. disallowed enol tautomer; 4. C/O ratio violation.