Fig 6. ¹³C- or ¹⁵N- excess of labeled amino acids in a Rv2323c knockout strain grown with [U-¹³C₆]arginine (A) or [U-¹⁵N₄]arginine (B).

Mtb wild type (Mtb), Rv2323c knockout mutant (Rv2323c-KO), and the Rv2323c knockout mutant complemented with the Rv2323c wild type gene (Compl.) are shown. Bacteria were cultured in minimal medium with glucose and glycerol as carbon sources and with either 5 mM of a 1:1 mixture of [U-¹³C₆]arginine and unlabeled arginine as sole nitrogen source (A) or with 5 mM of a 1:1 mixture of [U-¹⁵N₄]arginine and unlabeled arginine as sole nitrogen source (B). A) The ¹³C-excess of proline and other selected amino acids such as glutamate and aspartate is shown after 0, 3, 5, and 7 days of growth.¹³C-Excess at day 0 was <1%. B) The ¹⁵N-excess of glutamate and other selected amino acids such as aspartate and alanine is shown after 0, 3, and 5 days of growth (for more details see S3 Table). ¹⁵N-Excess at day 0 was < 1%. Mean values and standard deviations are shown for two independent biological experiments each measured in triplicate.