Fig. 2.

Growth of C. necator gene deletion strains on glycolate. (A) Growth experiments were conducted in 96-well plate readers in minimal medium (JMM) supplemented with 40 mM sodium glycolate. Doubling times (hours) and SDs of biological triplicates are shown in parentheses. NG corresponds to no growth. Triplicate growth experiments showed identical growth curves (±5%); hence, representative curves are shown. (B) The main pathway for growth on glycolate in C. necator proceeds via glycolate dehydrogenase and the glycerate pathway, which assimilated glyoxylate into central metabolism. (C) In the absence of the glycerate pathway, glyoxylate is decarboxylated mostly via the malate cycle and partly via oxalyl-CoA. Generated CO₂ and reducing equivalents are utilized in the Calvin cycle to support biomass formation. ΔC2, C₂ cycle knockout (ΔgcvTHP); ΔGDH, glycolate dehydrogenase knockout (ΔglcD-kch-glcE-glcF); ΔGP, glycerate pathway knockout (Δgcl-hyi-tsr); ΔMC, malate cycle knockout (ΔaceB); ΔOX, oxalate decarboxylation knockout (frc-oxc); ΔRub, Rubisco knockout (ΔcbbS2-cbbL2 ΔcbbSp− ΔcbbLp); WT, wild type.