Fan Haoxin, Bolhuis Henk, Stal Lucas J
Department of Marine Microbiology, Royal Netherlands Institute of Sea Research, PO Box 140, 4400 AC Yerseke, The Netherlands.
Department of Marine Microbiology, Royal Netherlands Institute of Sea Research, PO Box 140, 4400 AC Yerseke, The Netherlands Department of Aquatic Microbiology, Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94248, 1090 GE Amsterdam, The Netherlands
FEMS Microbiol Ecol. 2015 Mar;91(3). doi: 10.1093/femsec/fiu033. Epub 2014 Dec 24.
Denitrification was measured in three structurally different coastal microbial mats by using the stable isotope technique. The composition of the denitrifying community was determined by analyzing the nitrite reductase (nirS and nirK) genes using clone libraries and the GeoChip. The highest potential rate of denitrification (7.0 ± 1.0 mmol N m(-2) d(-1)) was observed during summer at station 1 (supra-littoral). The rates of denitrification were much lower in the stations 2 (marine) and 3 (intermediate) (respectively 0.1 ± 0.05 and 0.7 ± 0.2 mmol N m(-2) d(-1)) and showed less seasonality when compared to station 1. The denitrifying community at station 1 was also more diverse than that at station 2 and 3, which were more similar to each other than either of these stations to station 1. In all three stations, the diversity of both nirS and nirK denitrifiers was higher in summer when compared to winter. The location along the tidal gradient seems to determine the composition, diversity and activity of the denitrifier community, which may be driven by salinity, nitrate/nitrite and organic carbon. Both nirS and nirK denitrifiers are equally present and therefore they are likely to play a role in the denitrification of the microbial mats studied.
利用稳定同位素技术对三种结构不同的沿海微生物垫中的反硝化作用进行了测定。通过使用克隆文库和GeoChip分析亚硝酸还原酶（nirS和nirK）基因，确定了反硝化群落的组成。在夏季，1号站（潮上带）观测到最高的反硝化潜在速率（7.0±1.0 mmol N m(-2) d(-1)）。2号站（海洋）和3号站（中间带）的反硝化速率要低得多（分别为0.1±0.05和0.7±0.2 mmol N m(-2) d(-1)），与1号站相比，季节性也较弱。1号站的反硝化群落也比2号站和3号站更多样化，2号站和3号站彼此之间比它们与1号站中的任何一个都更相似。在所有三个站点中，nirS和nirK反硝化菌的多样性在夏季均高于冬季。沿潮汐梯度的位置似乎决定了反硝化菌群落的组成、多样性和活性，这可能受盐度、硝酸盐/亚硝酸盐和有机碳的驱动。nirS和nirK反硝化菌均有存在，因此它们可能在所研究的微生物垫的反硝化作用中发挥作用。
