淡水水体底泥厌氧氨氧化菌的初步富集培养与氨氧化特性

Preliminary cultivation and characteristics of the ammonium oxidation of anammox bacteria in freshwater sediments

对已通过16SrRNA基因方法检测到厌氧氨氧化菌(anammox菌)的江苏新沂河底泥样品在厌氧生物反应器中进行连续培养,研究这种新发现的anammox菌的生长特性,及其厌氧氨氧化效应.培养试验历时49d.经25d的启动期,反应器中氨氮和亚硝酸氮开始同时降低,并与厌氧氨氧化反应的化学计量关系类似.此后,反应器的氮转化量呈上升趋势(最大值接近0.17kg.m-.3d-1).底泥经培养后,anammox菌得到了富集,其数量从<1%提高到5.6%,其倍增时间为12d.研究还发现反应器生物量的流失,出水中含有与anammox菌特异性基因探针杂交并正进行增殖的细菌细胞,但其生物特性有待深入研究.

Anammox bacteria were detected in sediment samples from the Xinyi River in Jiangsu Province using 16S rRNA gene approach used in previous studies. In this work,the samples were cultivated continuously in anaerobic biological reactors to study the growth rate of the bacteria and the characteristics of anaerobic ammonium oxidation. The bacteria were cultivated for 49 days. After an adaptation period of 25 days,the concentration of both ammonium and nitrite in the reactors started to decrease simultaneously according to the anammox stoichiometry. Afterwards the nitrogen conversion rate showed an increasing trend,and its maximal value was up to 0.17 kg·m-3·d-1. After cultivation,the original anammox bacteria in the sediment samples were enriched and the percentage of the bacteria in the total bacteria was increased from lower than 1% to 5.6%,indicating that the doubling time of the amount of the bacteria is about 12 days. In addition,it was found that the biomass of the samples was lost from reactors during cultivation since the bacterial cells in the effluent were hybridized with the anammox-specific gene probes. Further study of the biological characteristics of the bacteria is needed.