两株不同大肠杆菌菌株释磷聚磷特性研究

The characteristics of phosphorus release and accumulation of the two different strains of Escherichia

目的研究来源不同、且部分生理特性不同的两株大肠杆菌菌株DCJ-1,DCJ-2在厌氧/好氧交替培养方式下释磷聚磷特性。方法以厌氧/好氧交替方式培养大肠杆菌菌株DCJ-1和DCJ-2,改变碳源种类,分别提供乙酸钠、丙酸钠、丁酸钠和不同比例乙酸钠/丙酸钠混合碳源,同时改变磷酸盐浓度,测定两菌株厌氧释磷量和好氧聚磷量,比较两者释磷聚磷特性的差异。结果 DCJ-1菌株在以乙酸盐为单一碳源,在磷浓度为40 mg/L时,具有最大释磷聚磷特性。在以不同比例乙酸钠/丙酸钠为混合碳源时,乙酸钠和丙酸钠比例为5∶1,2∶1,1∶2和1∶5时,DCJ-1表现出典型的聚磷特性。DCJ-2菌株在任何碳源情况下,在磷浓度10～40 mg/L时,均表现出一定的释磷聚磷特性,且释磷能力大于聚磷能力。在磷浓度50～60 mg/L时,两菌株均表现出只释磷不聚磷特性。结论 DCJ-1,DCJ-2两菌株释磷聚磷特性不同。揭示不同生物强化除磷反应器中同一菌种除磷效果不同原因可能在于其中菌株不同,不同菌株由于生理生长特性差异,导致聚磷释磷特性差异。

Aim To study the characteristics of phosphorus release and accumulation of two strains of Escherichia DCJ-1, DCJ-2, which vary in their resources and grow characteristics, cultured under anaerobic/aerobic conditions. Methods Supplied different carbon sources of acetate, propionate, butyrate and different ratios of acetate/ propionate, and under different concentrations of phosphorus, the phosphorus release and accumulation of two strains were measured and compared. Results DCJ-1 fed with acetate, considerable phosphorus was released and accumulated at 40 mg/L PO43 - , and DCJ-1 had the capacity of phosphorus release and accumulation when the ratios of acetate/propionate were 5： 1, 2： 1, 1 ： 2 and 1 ： 5. DCJ-2 had a rather weaker capability of phosphorus release and accumulation in any ratios of acetate/propionate with the phosphorus concentration of 10 -40 rag/L; and its capacity of phosphorus release was greater than accumulation. In the phosphorus concentration of 50 - 60 mg/L, DCJ-1 and DCJ-2 only released but did not accumulate phosphorus. Conclusion The characteristics of phosphorus release and accumulation of the two strains were different. It is implied that in different EBPRs, the phosphorus removal of the same bacteria is different owning to the different strains of bacterium in it, and different growing characteristics of strains resulted in different levels of phosphorus release and accumulation.