硝酸盐供应和巨芒草存在对异化硝酸盐还原细菌群落组成和活性的影响。
Effects of Nitrate Availability and the Presence of Glyceria maxima on the Composition and Activity of the Dissimilatory Nitrate-Reducing Bacterial Community.
出版信息
Appl Environ Microbiol. 1997 Mar;63(3):931-7. doi: 10.1128/aem.63.3.931-937.1997.
The effects of nitrate availability and the presence of Glyceria maxima on the composition and activity of the dissimilatory nitrate-reducing bacterial community were studied in the laboratory. Four different concentrations of NO(inf3)(sup-), 0, 533, 1434, and 2,905 (mu)g of NO(inf3)(sup-)-N g of dry sediment(sup-1), were added to pots containing freshwater sediment, and the pots were then incubated for a period of 69 days. Upon harvest, NH(inf4)(sup+) was not detectable in sediment that received 0 or 533 (mu)g of NO(inf3)(sup-)-N g of dry sediment(sup-1). Nitrate concentrations in these pots ranged from 0 to 8 (mu)g of NO(inf3)(sup-)-N g of dry sediment(sup-1) at harvest. In pots that received 1,434 or 2,905 (mu)g of NO(inf3)(sup-)-N g of dry sediment(sup-1), final concentrations varied between 10 and 48 (mu)g of NH(inf4)(sup+)-N g of dry sediment(sup-1) and between 200 and 1,600 (mu)g of NO(inf3)(sup-)-N g of dry sediment(sup-1), respectively. Higher input levels of NO(inf3)(sup-) resulted in increased numbers of potential nitrate-reducing bacteria and higher potential nitrate-reducing activity in the rhizosphere. In sediment samples from the rhizosphere, the contribution of denitrification to the potential nitrate-reducing capacity varied from 8% under NO(inf3)(sup-)-limiting conditions to 58% when NO(inf3)(sup-) was in ample supply. In bulk sediment with excess NO(inf3)(sup-), this percentage was 44%. The nitrate-reducing community consisted almost entirely of NO(inf2)(sup-)-accumulating or NH(inf4)(sup+)-producing gram-positive species when NO(inf3)(sup-) was not added to the sediment. The addition of NO(inf3)(sup-) resulted in an increase of denitrifying Pseudomonas and Moraxella strains. The factor controlling the composition of the nitrate-reducing community when NO(inf3)(sup-) is limited is the presence of G. maxima. In sediment with excess NO(inf3)(sup-), nitrate availability determines the composition of the nitrate-reducing community.
研究了硝酸盐供应和偃麦草（Glyceria maxima）的存在对异化硝酸盐还原菌群落组成和活性的影响。向含有淡水沉积物的锅中添加了四种不同浓度的硝酸盐（NO3-），分别为 0、533、1434 和 2905μgNO3--N g 干沉积物（-1），然后将这些锅培养 69 天。收获时，在接受 0 或 533μgNO3--N g 干沉积物（-1）的沉积物中未检测到 NH4+-N。这些锅中的硝酸盐浓度在收获时从 0 到 8μgNO3--N g 干沉积物（-1）。在接受 1434 或 2905μgNO3--N g 干沉积物（-1）的锅中，最终浓度分别在 10 和 48μgNH4+-N g 干沉积物（-1）和 200 和 1600μgNO3--N g 干沉积物（-1）之间变化。较高的 NO3--输入水平导致根际中潜在硝酸盐还原菌的数量增加和潜在硝酸盐还原活性增加。在根际沉积物样本中，反硝化对潜在硝酸盐还原能力的贡献从硝酸盐限制条件下的 8%变化到有足够硝酸盐供应时的 58%。在过量硝酸盐的 bulk 沉积物中，这一比例为 44%。当未向沉积物中添加硝酸盐时，硝酸盐还原群落几乎完全由不积累 NO2--或不产生 NH4+-的革兰氏阳性物种组成。添加硝酸盐会导致反硝化假单胞菌和莫拉氏菌菌株的增加。当硝酸盐有限时，控制硝酸盐还原群落组成的因素是偃麦草的存在。在过量的硝酸盐中，硝酸盐的可用性决定了硝酸盐还原群落的组成。
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