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Functional Responses of Salt Marsh Microbial Communities to Long-Term Nutrient Enrichment.

Graves CJ, Makrides EJ, Schmidt VT, Giblin AE, Cardon ZG, Rand DM - Appl. Environ. Microbiol. (2016)

Bottom Line: Homology-based taxonomic assignments of nitrous oxide reductase sequences in our data show that increases are spread over a broad taxonomic range, thus limiting detection from taxonomic data alone.Together, these results illustrate a functionally targeted yet taxonomically broad response of microbial communities to anthropogenic nutrient loading, indicating some resolution to the apparently conflicting results of existing studies on the impacts of nutrient loading in sediment communities.In addition, our results illustrate how whole-genome metagenomics combined with targeted hypothesis testing can reveal fine-scale responses of microbial communities to environmental disturbance.

View Article: PubMed Central - PubMed

Affiliation: Brown University, Department of Ecology and Evolutionary Biology, Providence, Rhode Island, USA.

No MeSH data available.


Related in: MedlinePlus

Physical characteristics of water and sediment from the reference and enriched creeks. A single water sample was collected at each site (A and B), while three sediment samples were collected per site (C). (A) Similar gradients between the two creeks from sites 1 through 5 in aspects unrelated to sewage outfall. (B) The sewage outfall is associated with significant nutrient enrichment, with orders-of-magnitude greater concentrations of nitrate/nitrite, phosphorus, and ammonia in water at all sites along the gradient. (C) Concentration of total carbon and nitrogen content in creek sediment are significantly higher in the enriched creek than in the reference creek (P < 0.01).
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Figure 1: Physical characteristics of water and sediment from the reference and enriched creeks. A single water sample was collected at each site (A and B), while three sediment samples were collected per site (C). (A) Similar gradients between the two creeks from sites 1 through 5 in aspects unrelated to sewage outfall. (B) The sewage outfall is associated with significant nutrient enrichment, with orders-of-magnitude greater concentrations of nitrate/nitrite, phosphorus, and ammonia in water at all sites along the gradient. (C) Concentration of total carbon and nitrogen content in creek sediment are significantly higher in the enriched creek than in the reference creek (P < 0.01).

Mentions: Two creeks located in Ipswich, MA, were chosen for this study, Greenwood and Egypt Creeks, here referred to as the enriched and reference creeks, respectively. Both creeks flowed into Plum Island Sound, were regularly fed by freshwater terrestrial streams, and experienced daily tidal height changes of 3 to 4 m. The two creeks were located within 5 km of one another, were surrounded by similar salt marsh plant communities, and had similar salinity gradients (Fig. 1; see also Fig. S1 in the supplemental material). However, the two creeks differed dramatically in the water quality of the freshwater input, with the enriched creek receiving input from Ipswich sewage effluent located near the head of the creek and the reference creek receiving input from a local drinking water reservoir. The treated sewage effluent in the enriched creek came from a wastewater treatment plant that has been in operation since 1958 and that UV-sterilizes wastewater before releasing it into the salt marsh. A satellite image showing the relative locations of the two creeks and the sampling sites within is shown in Fig. S1 in the supplemental material.


Functional Responses of Salt Marsh Microbial Communities to Long-Term Nutrient Enrichment.

Graves CJ, Makrides EJ, Schmidt VT, Giblin AE, Cardon ZG, Rand DM - Appl. Environ. Microbiol. (2016)

Physical characteristics of water and sediment from the reference and enriched creeks. A single water sample was collected at each site (A and B), while three sediment samples were collected per site (C). (A) Similar gradients between the two creeks from sites 1 through 5 in aspects unrelated to sewage outfall. (B) The sewage outfall is associated with significant nutrient enrichment, with orders-of-magnitude greater concentrations of nitrate/nitrite, phosphorus, and ammonia in water at all sites along the gradient. (C) Concentration of total carbon and nitrogen content in creek sediment are significantly higher in the enriched creek than in the reference creek (P < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4836423&req=5

Figure 1: Physical characteristics of water and sediment from the reference and enriched creeks. A single water sample was collected at each site (A and B), while three sediment samples were collected per site (C). (A) Similar gradients between the two creeks from sites 1 through 5 in aspects unrelated to sewage outfall. (B) The sewage outfall is associated with significant nutrient enrichment, with orders-of-magnitude greater concentrations of nitrate/nitrite, phosphorus, and ammonia in water at all sites along the gradient. (C) Concentration of total carbon and nitrogen content in creek sediment are significantly higher in the enriched creek than in the reference creek (P < 0.01).
Mentions: Two creeks located in Ipswich, MA, were chosen for this study, Greenwood and Egypt Creeks, here referred to as the enriched and reference creeks, respectively. Both creeks flowed into Plum Island Sound, were regularly fed by freshwater terrestrial streams, and experienced daily tidal height changes of 3 to 4 m. The two creeks were located within 5 km of one another, were surrounded by similar salt marsh plant communities, and had similar salinity gradients (Fig. 1; see also Fig. S1 in the supplemental material). However, the two creeks differed dramatically in the water quality of the freshwater input, with the enriched creek receiving input from Ipswich sewage effluent located near the head of the creek and the reference creek receiving input from a local drinking water reservoir. The treated sewage effluent in the enriched creek came from a wastewater treatment plant that has been in operation since 1958 and that UV-sterilizes wastewater before releasing it into the salt marsh. A satellite image showing the relative locations of the two creeks and the sampling sites within is shown in Fig. S1 in the supplemental material.

Bottom Line: Homology-based taxonomic assignments of nitrous oxide reductase sequences in our data show that increases are spread over a broad taxonomic range, thus limiting detection from taxonomic data alone.Together, these results illustrate a functionally targeted yet taxonomically broad response of microbial communities to anthropogenic nutrient loading, indicating some resolution to the apparently conflicting results of existing studies on the impacts of nutrient loading in sediment communities.In addition, our results illustrate how whole-genome metagenomics combined with targeted hypothesis testing can reveal fine-scale responses of microbial communities to environmental disturbance.

View Article: PubMed Central - PubMed

Affiliation: Brown University, Department of Ecology and Evolutionary Biology, Providence, Rhode Island, USA.

No MeSH data available.


Related in: MedlinePlus