Fig. 3: Analysis of intracellular metabolites in the ΔglgC mutant cyanobacteria.

The wild-type (blue circles) and ΔglgC mutant (orange squares) cyanobacteria were cultured using media with initial nitrate concentrations of 7.5 mM (low nitrogen, LN) and 17.6 mM (high nitrogen, HN); then, the intracellular metabolites were comprehensively analyzed. The solid and dotted lines represent single and multiple enzymatic steps, respectively. a Metabolites in the CBB cycle and glycolysis, b metabolites in the glycolysis, TCA cycle, and GS-GOGAT cycle. 2-OG 2-oxoglutarate, 2-PGA 2-phosphoglycerate, 3-PGA 3-phosphoglycerate, AcCoA acetyl-coenzyme A, Aco aconitate, ADP adenosine diphosphate, ADP-Glc adenosine diphosphate-glucose, Ala alanine, Arg arginine, Asn asparagine, Asp aspartate, ATP adenosine triphosphate, CBB cycle Calvin–Benson–Bassham cycle, Cit citrate, Cys cysteine, DCW dry cell weight, F6P fructose-6-phosphate, Fum fumarate, G1P glucose-1-phosphate, GAP glyceraldehyde-3-phosphate, Gln glutamine, GS-GOGAT cycle glutamine synthase–glutamate synthase cycle, Glu glutamate, Gly glycine, His histidine, Icit isocitrate, Ile isoleucine, Lac lactate, Leu leucine, Lys lysine, Mal malate, Met methionine, OAA oxaloacetate, PEP phosphoenolpyruvate, Phe phenylalanine, Pro proline, Pyr pyruvate, Ru5P ribulose-5-phosphate, RuBP ribulose-1,5-bisphosphate, S7P sedoheptulose-7-phosphate, Ser serine, SSA succinic semialdehyde, Suc succinate, TCA cycle tricarboxylic acid cycle, Thr threonine, Trp tryptophan, Tyr tyrosine, Val valine. Error bars indicate standard deviation of three replicate experiments (*P < 0.05 by Welch’s t test).