Incorporation of C1402 into Organic Compounds by Cell-free Extracts of Autotrophically Grown Hydrogenomonas sp. ∗

Abstract

Summary

Cell-free extracts from auto-trophically grown Hydrogenomonas, in the presence of NaHC¹⁴O3 and certain organic acids, are capable of performing the following reactions: 1) To incorporate C¹⁴ into malic acid, in the presence of TPNH or DPNH, pyruvic acid, and Mn⁺⁺ ions; the same is accomplished when malic acid plus TPN or DPN instead of the reduced forms of the coenzymes are used in the above reaction mixtures. 2) To incorporate C¹⁴ into the beta-carboxyl group of oxalacetic acid when NaHC¹⁴O3 is incubated with pyruvic acid, Mn⁺⁺ ions, and oxalacetic acid; ATP is required for this reaction. 3) To incorporate C¹⁴ into isocitric acid when NaHC¹⁴O₃ is incubated with alpha-ketoglutaric acid, Mn⁺⁺ ions, TPNH, or with isocitric acid and TPN in place of TPNH. Cell-free extracts of heterotrophically grown Hydrogenomonas, like the extracts from autotrophically grown cells, are able to accomplish the same reactions.