Table 4. Influence of nitrogen sources on growth and EPS production by H. xianhensis SUR308.
| Nitrogen source | Growth |
Production of EPS, g/L | |
| OD at 540 nm | DCW, g/L | ||
| Control | 7.71 ± 0.06 | 3.04 ± 0.02 | 5.82 ± 0.01 |
| Tryptone | 6.27 ± 0.06 | 3.32 ± 0.02 | 5.80 ± 0.01 |
| Beef extract | 8.13 ± 0.12 | 4.51 ± 0.01 | 5.50 ± 0.01 |
| Casein hydrolysate | 8.52 ± 0.03 | 4.37 ± 0.02 | 6.56 ± 0.00 |
| Yeast extract | 7.71 ± 0.06 | 3.72 ± 0.00 | 6.49 ± 0.01 |
| Ammonium sulfate | 4.53 ± 0.02 | 1.81 ± 0.01 | 2.04 ± 0.01 |
| Ammonium nitrate | 0.32 ± 0.02 | 0.31 ± 0.01 | 1.51 ± 0.02 |
| Sodium nitrate | 1.05 ± 0.10 | 0.72 ± 0.02 | 1.52 ± 0.02 |
| Potassium nitrate | 0.633 ± 0.03 | 0.63 ± 0.03 | 1.23 ± 0.01 |
| Ammonium chloride | 2.28 ± 0.03 | 0.68 ± 0.01 | 2.40 ± 0.01 |
Fermentations were carried out in MY medium [(g/L): NaCl, 25; MgCl2·6H2O, 9; MgSO4·7H2O, 13; CaCl2·2H2O, 0.2; KCl, 1.3; NaHCO3, 0.05; NaBr, 0.15; FeCl3·6H2O, 0.005; glucose, 30; yeast extract, 3; malt extract, 3; protease peptone, 5] under continuous shaking (120 rpm) at 32 °C and pH 7.2 with 2% (v/v) initial inoculum. All values were taken in triplicates and the average ± SE was recorded after 11 days of incubation. One way ANOVA has been carried out for each row with the P value of 0.05. Bonferroni's post-test shows the growth (OD at 540 nm), DCW, production of EPS were not significantly different (P > 0.05).