一株自养硝化细菌培养条件的优化

摘要

针对前期筛选的自养硝化杆菌(Nitrobacter)菌株y3-2,以实时荧光定量核酸扩增检测系统(qPCR)测定的菌液终浓度为指标,设计单因素试验和正交试验对其培养基和培养条件进行优化.结果表明,优化的硝化杆菌y3-2的培养基中CaCO3、Na2CO3、NaNO2浓度分别为0.5、1.0、0.5 g/L.最佳培养条件为培养温度28℃、pH 8.0、摇床转速200 r/Min.优化后硝化杆菌y3-2的发酵周期由优化前的7d缩短至4d,菌液终浓度达到4.31×109 CFU/mL.%The culture medium and culture conditions for an autotrophic nitrifying bacterium (Nitrobacter) strain y3-2 were optimized by single factor experiments and orthogonal test using final concentration of bacteria tested by Real-time quantitative PCR detecting system (qPCR) as indicator.The results showed that the optimum concentration of CaCO3,Na2CO3 and NaNO2 in Nitrobacter strain y3-2 culture medium was 0.5,1.0 and 0.5 g/L.The optimal culture conditions were temperature 28 ℃,pH 8.0,shaker speed 200 r/min.After optimization,the batch fermentation cycle for y3-2 was shortened from 7 d to 4 d,while bacteria concentration was increased to 4.31×109CFU/mL.