Microbial community responses to nitrogen- and phosphorus- deficient nutrient inputs: microplankton dynamics and biochemical characterization

Abstract. Ocean acidification resulting from the uptake of anthropogenic carbon dioxide (CO2) by the ocean is considered a major threat to marine ecosystems. Here we examined the effects of ocean acidification on microbial community dynamics in the eastern Baltic Sea during the summer of 2012 when inorganic nitrogen and phosphorus were strongly depleted. Large-volume in situ mesocosms were employed to mimic present, future and far future CO2 scenarios. All six groups of phytoplankton enumerated by flow cytometry ( <  20 µm cell diameter) showed distinct trends in net growth and abundance with CO2 enrichment. The picoeukaryotic phytoplankton groups Pico-I and Pico-II displayed enhanced abundances, whilst Pico-III, Synechococcus and the nanoeukaryotic phytoplankton groups were negatively affected by elevated fugacity of CO2 (fCO2). Specifically, the numerically dominant eukaryote, Pico-I, demonstrated increases in gross growth rate with increasing fCO2 sufficient to double its abundance. The dynamics of the prokaryote community closely followed trends in total algal biomass despite differential effects of fCO2 on algal groups. Similarly, viral abundances corresponded to prokaryotic host population dynamics. Viral lysis and grazing were both important in controlling microbial abundances. Overall our results point to a shift, with increasing fCO2, towards a more regenerative system with production dominated by small picoeukaryotic phytoplankton.

Download Full-text

Response of Aerobic Granular Sludge to the Long-Term Presence of CuO NPs in A/O/A SBRs: Nitrogen and Phosphorus Removal, Enzymatic Activity, and the Microbial Community

Environmental Science & Technology ◽

10.1021/acs.est.7b02768 ◽

2017 ◽

Vol 51 (18) ◽

pp. 10503-10510 ◽

Cited By ~ 19

Author(s):

Xiao-ying Zheng ◽

Dan Lu ◽

Wei Chen ◽

Ya-jie Gao ◽

Gan Zhou ◽

...

Keyword(s):

Microbial Community ◽

Enzymatic Activity ◽

Phosphorus Removal ◽

Granular Sludge ◽

Aerobic Granular Sludge ◽

Nitrogen And Phosphorus ◽

Nitrogen And Phosphorus Removal ◽

Cuo Nps

Download Full-text

Stream Restoration for Legacy Sediments at Gramies Run, Maryland: Early Lessons from Implementation, Water Quality Monitoring, and Soil Health

Water ◽

10.3390/w12082164 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2164

Author(s):

Katie Mattern ◽

Alyssa Lutgen ◽

Nathan Sienkiewicz ◽

Grant Jiang ◽

Jinjun Kan ◽

...

Keyword(s):

Water Quality ◽

Riparian Vegetation ◽

Stream Restoration ◽

Soil Health ◽

Water Quality Monitoring ◽

Quality Monitoring ◽

Nutrient Inputs ◽

Nitrogen And Phosphorus ◽

Partial Removal ◽

Riparian Trees

While stream restorations are increasingly being adopted to mitigate sediment and nutrient inputs and to meet water quality regulatory targets, less information is available on the drivers behind the design, implementation, effectiveness, and cost of restorations. We address these issues for a $4.2 million stream restoration for legacy sediments implemented for a rural Piedmont stream in Maryland, USA. A total of 1668 m of stream was restored in three phases, which included the partial removal of legacy sediments, the grading of streambanks, floodplain creation, channel reshaping with meanders and pool-riffle forms, the raising of the stream bed, and the planting of riparian vegetation. The sediment, nitrogen, and phosphorus concentrations and fluxes were monitored before- and during the restoration phases. The sites selected for restoration had legacy sediments vulnerable to erosion and were on state-owned land. The restoration design was based on the need to maintain mature riparian trees and preserve existing sensitive wetland habitats. Water quality monitoring indicated that the sediment and nutrient fluxes increased during the restoration phase and were attributed to disturbance associated with construction activities and increased runoff. We also recommend that soil health needs to be included as an integral component to enhance the effectiveness and resilience of stream restorations.

Download Full-text

Responses of soil microbial communities and enzyme activities to nitrogen and phosphorus additions in Chinese fir plantations of subtropical China

Biogeosciences Discussions ◽

10.5194/bgd-12-10359-2015 ◽

2015 ◽

Vol 12 (13) ◽

pp. 10359-10387 ◽

Cited By ~ 4

Author(s):

W. Y. Dong ◽

X. Y. Zhang ◽

X. Y. Liu ◽

X. L. Fu ◽

F. S. Chen ◽

...

Keyword(s):

Microbial Community ◽

Microbial Communities ◽

Enzyme Activities ◽

Microbial Community Composition ◽

Soil Microbial Communities ◽

Chinese Fir ◽

Subtropical China ◽

Nitrogen And Phosphorus ◽

Soil Microbial ◽

Nutrient Additions

Abstract. Nitrogen (N) and phosphorus (P) additions to forest ecosystems are known to influence various above-ground properties, such as plant productivity and composition, and below-ground properties, such as soil nutrient cycling. However, our understanding of how soil microbial communities and their functions respond to nutrient additions in subtropical plantations is still not complete. In this study, we added N and P to Chinese fir plantations in subtropical China to examine how nutrient additions influenced soil microbial community composition and enzyme activities. The results showed that most soil microbial properties were responsive to N and/or P additions, but responses often varied depending on the nutrient added and the quantity added. For instance, there were more than 30 % greater increases in the activities of β-Glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG) in the treatments that received nutrient additions compared to the control plot, whereas acid phosphatase (aP) activity was always higher (57 and 71 %, respectively) in the P treatment. N and P additions greatly enhanced the PLFA abundanceespecially in the N2P treatment, the bacterial PLFAs (bacPLFAs), fungal PLFAs (funPLFAs) and actinomycic PLFAs (actPLFAs) were about 2.5, 3 and 4 times higher, respectively, than in the CK. Soil enzyme activities were noticeably higher in November than in July, mainly due to seasonal differences in soil moisture content (SMC). βG or NAG activities were significantly and positively correlated with microbial PLFAs. There were also significant relationships between gram-positive (G+) bacteria and all three soil enzymes. These findings indicate that G+ bacteria is the most important microbial community in C, N, and P transformations in Chinese fir plantations, and that βG and NAG would be useful tools for assessing the biogeochemical transformation and metabolic activity of soil microbes. We recommend combined additions of N and P fertilizer to promote soil fertility and microbial activity in this kind of plantation.

Download Full-text