Table 3.

Available measurements of ¹³C/¹²C isotope effects (ε) from diverse forms of purified RuBisCO enzyme, measured under saturating CO₂ levels.

Group	Species	RuBisCO form	13C/12C isotope effect, ε (‰)	Isotope effect reference
Proteobacteria	Solemya velum bivalve symbiont	IA	24.4	[19]
Cyanobacteriaa	Prochlorococcus marinus MIT9313	IA	24.0	[16]
Cyanobacteriaa	Synechococcus elongatus PCC6301	IB	22.0	[17]
Land plant	Flaveria bidentis	IB	27.8	[18]
Land plant	Flaveria floridana	IB	28.6	[18]
Land plant	Nicotiana tabacum	IB	29	[18]
Land plant	Spinacia oleracea	IB	28.2–30.3	[15, 17, 19]
Proteobacteria	Ralstonia eutropha	IC	19.0	[136]
Proteobacteria	Rhodobacter sphaeroides	IC	22.4	[136]
Coccolithophore	Emiliana huxleyi	ID	11.1	[137]
Diatom	Skeletonema costatum	ID	18.5	[27]
Proteobacteria	Rhodospirillum rubrum	II	17.8–23.8	[17, 18, 26, 73]
Proteobacteria	Riftia pachyptila symbiont	II	19.5	[74]

^aHorizontal transfer of RuBisCO Form I genes likely occurred within cyanobacteria [72, 138].