Table 2.
l-[14C]arginine uptake and metabolic products in Anabaena sp. strains PCC 7120 (wild type) and CSMI11 (Δalr2310).
| BG11 | BG110 | |||||||
|---|---|---|---|---|---|---|---|---|
| PCC 7120 | CSMI11 | PCC 7120 | CSMI11 | |||||
| 10 min | 30 min | 10 min | 30 min | 10 min | 30 min | 10 min | 30 min | |
| Arginine taken up (nmol·[mg Chl]−1) | 73.3 | 115.9 | 57.3 | 72.4 | 93.7 | 162.3 | 91.3 | 124.5 |
| Labeled compounds (%) | ||||||||
| Origin | 7.5 | 18.6 | 1.8 | 8.4 | 10.0 | 12.4 | 10.2 | 14.2 |
| Arginine | 54.8 | 21.6 | 52.6 | 19.2 | 66.7 | 50.3 | 51.1 | 17.4 |
| Agmatine | 0.4 | 0.4 | 2.9 | 10.4 | 0.2 | 0.3 | 7.1 | 15.4 |
| Aspartate | 1.5 | 1.5 | 2.1 | 1.8 | 0.5 | 0.8 | 1.1 | 1.2 |
| Glutamate | 7.0 | 33.0 | 24.6 | 52.0 | 1.6 | 10.7 | 8.6 | 37.1 |
| Glutamine/Citrulline | 6.4 | 3.2 | 3.7 | 1.2 | 2.5 | 2.0 | 1.8 | 1.1 |
| Ornithine | 2.2 | 1.0 | 1.6 | 1.2 | 2.5 | 1.6 | 2.4 | 1.5 |
| Proline | 15.4 | 17.4 | 8.6 | 2.7 | 9.5 | 15.8 | 9.3 | 6.4 |
| Spot #6 | 4.6 | 2.5 | 2.1 | 1.5 | 6.6 | 5.1 | 8.4 | 3.3 |
| Spot #7 | – | 0.8 | – | 1.7 | – | 1.3 | – | 2.4 |
Filaments of the indicated strains grown in BG110 NH4+ medium and incubated for 24 h in BG11 or BG110 medium were used at 5–10 μg Chl mL−1 in assays of uptake of 1 μmol/L l-[14C]arginine as described in Materials and Methods. After 10 and 30 min of incubation, uptake of arginine was determined and metabolites in the suspensions were analyzed by TLC. Cell-associated metabolites are presented as the percentage of the sum of radioactivity in 14C-labeled chromatographic spots after subtraction of extracellular arginine. Compounds that do not move with the used solvents accumulate in the origin of the chromatography.