Post on 25-May-2020
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Linking Nutrient Impacts on Microbial Community Structure and Function with
Biogeochemistry in the Everglades
A. Ogram, A. Chauhan, K. Inglett, K. Jayachandran, and S. Newman
Water (Aerobic)
ANAEROBIC
Plant Detritus Monomers and Oligomers
Short chain fatty acids(propionate, butyrate, etc);
alcohols.
H2 and CO2
AcetateAcetate H2 and CO2
CH4S- and CO2
Acetate
Fermentative Bacteria
HomoacetogensSyntrophic Bacteria
Sulfate Reducing Bacteria Methanogens
Methanotrophs
Penton and Newman, 2008
Dec
reas
ing
P In
fluen
ce
Decreasing N Influence
Penton and Newman, 2008
Dec
reas
ing
P In
fluen
ce
Decreasing N Influence
Nutrient Study – Benthic Horizon
1enr
2enr
3enr
ENP- enr
1ref
2ref 3refENP-ref
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0
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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
E cell/E n
Ecel
l/Ep
Dec
reas
ing
P In
fluen
ce
Decreasing N Influence• C mineralization less influenced by N and P at all enriched sites
• WCA-3A exhibited greatest P shift while ENP-TS exhibited greatest N shift
1P ***2P ** 3P ***
ENP-P ***
2N*
1N3N**
ENP-N**
17Penton and Newman, 2007
Periphyton matsPeriphyton mats
••Periphyton refers to the Periphyton refers to the assemblages of prokaryotic and assemblages of prokaryotic and eukaryotic algae. eukaryotic algae.
••Develop at interfaces of waterDevelop at interfaces of water--solid substrates and watersolid substrates and water--air. air.
Photo credit: P. Inglett
AP activity appears to be associated with cells that surround the cluster of chlorophyll containing filamentous cells
APAP
DAPIDAPI
ChlorophyllChlorophyll
Filaments showing AP activity did not appear to have any chlorophyll
Empty sheath of cyanobacteria (CS) with AP activity. C: chlorophyll
5500
(μ(μm)m)
10µm
AP
C
Empty CSvi
10µm
AP
C
Empty CSvi
1010μμmm
Chlorophyll containing cells (C) appear to be closely associated with sites of AP activity.
Cooperative relationship within a periphyton mat Cooperative relationship within a periphyton mat from a low P regionfrom a low P region
UV-IMPACTED MATCO2CO2
N2N2
Lysis
ALGAE
APA
BACTERIA
Uptake
Lysis
C, NC, N
Resolution of SRP assemblages from P-impacted, transition, and low P sites taken over one year.
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0
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0.4
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-0.6 -0.4 -0.2 0 0.2 0.4 0.6
PCA AXIS 1 (30.4%)
PC
A A
XIS
1 (1
7.5%
)
F1F4U3
Distribution of sulfate reducing bacteria
P-impacted F1
Transition F4Low nutrient U3
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-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5
PCA AXIS 1 (29.5%)
PC
A A
XIS
1 (1
1.1%
)
F1F4U3
Resolution of methanogenic assemblages from P-impacted, transition, and low P-sites taken over one year.
Distribution of methanogens
Low Nutrient
Transition
P-impacted
Syntrophs Methanospirillum
Methanosaeta
ButyrateAcetateCH4
H2 CH4
Tree Islands
• Hammocks more diverse and rich• High relative ratio of 342-361 bp- hammocks• Short lengths- 314-327- Alpha and cynaobacteria• Intermediate lengths- beta, gamma and delta
proteobacteria, flexibacter-bacteriodes-cytophaga• Longest domains- low and high G + C gram positive
bacteria• Gamma proteobacteria grow on nutrient rich and alpha
proteobacteria on nutrient poor media
Conclusions from Tree Island Studies
Hammocks are more microbial diverse and rich than bayhead and swamps
Carbon and phosphorous determine the structure of microbial community in tree island ecosystems under the influence of moisture
Summary
• Microbial communities in various compartments differ as a function of nutrient enrichment:– Nutrient enrichment changes community
structure and activities
• Activities important to restoration are likely impacted by nutrient enrichment