Division of Environmental Engineering, Faculty of Engineering, Hokkaido University.
Microbes Environ. 2013;28(4):436-43. doi: 10.1264/jsme2.me13077. Epub 2013 Nov 8.
Enrichment cultures of anaerobic ammonium oxidation (anammox) bacteria as planktonic cell suspensions are essential for studying their ecophysiology and biochemistry, while their cultivation is still laborious. The present study aimed to cultivate two phylogenetically distinct anammox bacteria, "Candidatus Brocadia sinica" and "Ca. Scalindua sp." in the form of planktonic cells using membrane bioreactors (MBRs). The MBRs were continuously operated for more than 250 d with nitrogen loading rates of 0.48-1.02 and 0.004-0.09 kgN m(-3) d(-1) for "Ca. Brocadia sinica" and "Ca. Scalindua sp.", respectively. Planktonic anammox bacterial cells were successfully enriched (>90%) in the MBRs, which was confirmed by fluorescence in-situ hybridization and 16S rRNA gene sequencing analysis. The decay rate and half-saturation constant for NO2(-) of "Ca. Brocadia sinica" were determined to be 0.0029-0.0081 d(-1) and 0.47 mgN L(-1), respectively, using enriched planktonic cells. The present study demonstrated that MBR enables the culture of planktonic anammox bacterial cells, which are suitable for studying their ecophysiology and biochemistry.
富集培养厌氧氨氧化（anammox）细菌的浮游细胞悬浮液对于研究其生理生态学和生物化学特性至关重要，但这种培养方法仍然很繁琐。本研究旨在利用膜生物反应器（MBR）以浮游细胞的形式培养两种在系统发育上有明显区别的厌氧氨氧化菌，即“Candidatus Brocadia sinica”和“Ca. Scalindua sp.”。MBR 连续运行超过 250 天，氮负荷分别为 0.48-1.02 和 0.004-0.09 kgN m(-3) d(-1)，用于“Ca. Brocadia sinica”和“Ca. Scalindua sp.”。通过荧光原位杂交和 16S rRNA 基因测序分析证实，MBR 中成功富集了（>90%）浮游氨氧化细菌细胞。用富集的浮游细胞测定了“Ca. Brocadia sinica”的 NO2(-)衰减率和半饱和常数，分别为 0.0029-0.0081 d(-1)和 0.47 mgN L(-1)。本研究表明，MBR 能够培养浮游氨氧化细菌细胞，适用于研究其生理生态学和生物化学特性。
