A heterotrophic nitrification and aerobic denitrification (HNAD) strain WN1 with significant tolerance against high ammonium concentrations was isolated from a reactor treating high-strength ammonium organic wastewater. Based on colony morphology and 16S rDNA analysis, it was identified as Corynebacterium glutamicum. The growth and metabolic characteristics of WN1 were studied under different initial ammonium concentrations of 500, 1000, 1500, 2000, 2500 and 3000mg/L, respectively. The results showed that strain WN1 could still grow well (48h, OD600=3.264) at an initial ammonium concentration of 3000mg/L, corresponding to a free ammonia concentration of 590.2mg/L. As initial ammonium concentrations increased from 500 to 3000mg/L, the maximum ammonium conversion rate (Rm) of strain WN1increased from 15.93 to 43.29mg/(L·h). Additionally, the average conversion rates of ammonium and COD were 7.06~9.36mg/(L·h) and 95.63~199.13mg/(L·h), respectively. Furthermore, the Haldane model was used to characterize the growth and substrate degradation properties of strain WN1under different initial ammonium concentrations (R2 = 0.99). Strain WN1had a maximum specific growth rate of umax = 0.36h-1, a maximum specific ammonium degradation rate of rmax = 6.45gN/(gDCW·d), and a maximum specific COD degradation rate of rmax = 122.85gCOD/(gDCW·d). The ammonium inhibition constant Ki of strain WN1was 3749.49mg/L, indicating greater resistance to high ammonium concentrations compared with other autotrophic or heterotrophic ammonium-oxidizing bacteria. The results suggest that strain WN1is promising for treating high-strength ammonium organic wastewater.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |