TABLE 1.
NaCl-induced osmotic effects on production of HMW EPS I and LMW EPS I by R. meliloti Rm2011 mutants characterized by alterations in the ExoP proteina
| Strain/plasmid | Mutation | Glucose equivalents (mg/liter), HMW EPS:LMW EPS (%) at osmolarity (osmol/liter):
|
||||
|---|---|---|---|---|---|---|
| 0.09 | 0.18 | 0.29 | 0.38 | 0.48 | ||
| Rm2011 | None (wild type) | 790, 31:69 | 802, 58:42 | 782, 72:28 | 785, 79:21 | 766, 77:23 |
| RmΔP*1 | exoP* | 90, 0:100 | 250, 11:89 | 265, 27:73 | 250, 49:51 | 243, 51:49 |
| RmΔexoP/pExoP | None (wild type) | 781, 30:70 | 792, 57:43 | 782, 73:27 | 786, 78:22 | 770, 77:23 |
| RmΔexoP/pExoP-R443L | exoP, R443L | 777, 3:97 | 788, 22:78 | 782, 50:50 | 784, 54:46 | 766, 59:41 |
| RmΔexoP/pExoP-P457S | exoP, P457S | 803, 2:98 | 807, 20:80 | 805, 52:48 | 789, 58:42 | 775, 60:40 |
a
The data represent averages of at least five independent experiments. Strains were grown for 10 days in GMS medium supplemented with sodium chloride to the osmolarity specified. Standard deviations were equal to or less than 8 and 4% for the determination of the total amount of extracellular carbohydrates in glucose equivalents and the ratio of HMW to LMW EPS, respectively.