不同培养基对湖泊氨氧化细菌MPN计数的影响

Effect of Different Media on MPN Estimation of Ammonia-oxidizing Bacteria in Lakes

本文研究了培养时间、培养基类型、硫酸铵浓度对湖泊沉积物与水中氨氧化细菌(AOB)MPN计数的影响。结果表明,MPN值随培养时间的延长而增大,且趋于稳定。对不同样品而言,培养40d后,MSF培养基均给出稳定的MPN值。在3种不同类型的培养基(XZ-AOB、MSF、SW)中,MSF产生的MPN值最大。此外,培养基中的硫酸铵浓度对MPN计数亦有重要影响,与沉积物AOB相比,湖水AOB对硫酸铵浓度更为敏感。

The MPN method was used to enumerate ammonia-oxidizing bacteria （AOB） in water and sediments of several shallow lakes. The suitable incubation time, medium types and substrate （ammonium sulphate） concentrations were studied. The results showed that, MPN values increased with the incubation time, reaching a stable maximum at some time stages, which was 40 days in all the samples for MSF medium. Among the three media used （XZ-AOB, MSF, SW）, MSF give the highest MPN value. In addition, ammonium sulphate concentration in medium was an important factor affecting MPN estimation of AOB. Compared to AOB in lake sediments, AOB in lake water was more sensitive to ammonium sulphate concentration.