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

-10

0

10

20

30

40

50

60

70

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.

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

-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

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

-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