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Long-term sulfide input enhances chemoautotrophic denitrification rather than DNRA in freshwater lake sediments.
- Source :
- Environmental Pollution; Feb2021, Vol. 270, pN.PAG-N.PAG, 1p
- Publication Year :
- 2021
-
Abstract
- Partitioning between nitrate reduction pathways, denitrification and dissimilatory nitrate reduction to ammonium (DNRA) determines the fate of nitrate removal and thus it is of great ecological importance. Sulfide (S<superscript>2−</superscript>) is a potentially important factor that influences the role of denitrification and DNRA. However, information on the impact of microbial mechanisms for S<superscript>2−</superscript> on the partitioning of nitrate reduction pathways in freshwater environments is still lacking. This study investigated the effects of long-term (108 d) S<superscript>2−</superscript> addition on nitrate reduction pathways and microbial communities in the sediments of two different freshwater lakes. The results show that the increasing S<superscript>2−</superscript> addition enhanced the coupling of S<superscript>2−</superscript> oxidation with denitrification instead of DNRA. The sulfide-oxidizing denitrifier, Thiobacillus , was significantly enriched in the incubations of both lake samples with S<superscript>2−</superscript> addition, which indicates that it may be the key genus driving sulfide-oxidizing denitrification in the lake sediments. During S<superscript>2−</superscript> incubation of the Hongze Lake sample, which had lower inherent organic carbon (C) and sulfate (SO 4 <superscript>2−</superscript>), Thiobacillus was more enriched and played a dominant role in the microbial community; while during that of the Nansi Lake sample, which had higher inherent organic C and SO 4 <superscript>2−</superscript>, Thiobacillus was less enriched, but increasing abundances of sulfate reducing bacteria (Desulfomicrobium , Desulfatitalea and Geothermobacter) were observed. Moreover, sulfide-oxidizing denitrifiers and sulfate reducers were enriched in the Nansi Lake control treatment without external S<superscript>2−</superscript> input, which suggests that internal sulfate release may promote the cooperation between sulfide-oxidizing denitrifiers and sulfate reducers. This study highlights the importance of sulfide-driven denitrification and the close coupling between the N and S cycles in freshwater environments, which are factors that have often been overlooked. Image 1 • Long-term sulfide input favors chemoautotrophic denitrification instead of DNRA. • Thiobacillus was the key genus driving sulfide-oxidizing denitrification. • Inherent C and S in the samples influenced microbial interactions under S<superscript>2−</superscript> input. • Internal SO 4 <superscript>2−</superscript> release increased cooperation between N and S cycling microorganisms. Long-term sulfide input favors chemoautotrophic denitrifiers instead of DNRA bacteria in freshwater sediments. [ABSTRACT FROM AUTHOR]
- Subjects :
- LAKES
LAKE sediments
DENITRIFICATION
SULFATE-reducing bacteria
SULFIDES
SULFIDE ores
Subjects
Details
- Language :
- English
- ISSN :
- 02697491
- Volume :
- 270
- Database :
- Supplemental Index
- Journal :
- Environmental Pollution
- Publication Type :
- Academic Journal
- Accession number :
- 148075132
- Full Text :
- https://doi.org/10.1016/j.envpol.2020.116201