Publication Date:
2011-06-01
Description:
Distribution of typical denitrifying functional genes and diversity of the nirS -encoding bacterial community related to environmental characteristics of river sediments Biogeosciences Discussions, 8, 5251-5280, 2011 Author(s): S. Huang, C. Chen, Q. Wu, R. Zhang, and X. Yang Denitrification in river sediments leads to nitrate removal from the aquatic system; therefore, it is necessary to understand functional diversity of denitrifier communities in the system. Sediment samples (0–25 cm depth) were collected from three typical locations along the Pearl River. The real-time PCR approach was used to measure the abundance of nitrate ( narG ), nitrite ( nirS , nirK and nrfA ), and nitrous oxide ( nosZ ) reductase genes from the sediment samples. Assemblages of nirS , nirK and nosZ indicated that complete denitrification occurred in sediment cores, with the greatest number of gene copies from 5–15 cm depth. Dissimilatory nitrate reduction appeared to be important below 15 cm depth, based on increasing gene copies of narG and nrfA with sediment depth. There was a close match (78–94 %) between the nirS sequences recovered from Pearl River sediment and those detected in estuarine and marine sediments as well as active sludge, suggesting that domestic sewage inputs and irregular tides. Canonical correspondence analysis indicated that the spatial distribution of denitrifying bacteria was highly correlated with dissolved inorganic N (DIN: NH 4 + , NO 2
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences
