bacterioplankton dynamics during a mesocosm-simulated oil spill eva teira 1, jm gasol 2, i...
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BACTERIOPLANKTON DYNAMICS DURING A MESOCOSM-SIMULATED OIL SPILL
Eva Teira1, JM Gasol2, I Lekunberri2, XAG Morán3,
E Fernández1, XA Álvarez-Salgado4, F.G. Figueiras4
1 Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo,
36310-Vigo
2 Departament de Biología Marina i Oceanografia, Institut de Ciències del
Mar-CMIMA, CSIC, Pg.Marítim de la Barceloneta 37-49, 08003, Barcelona
3 Instituto Español de Oceanografía-Xixón, Camín de l’Arbeyal s/n, 33212,
Xixón
4 Instituto de Investigaciones Marinas-IIM, CSIC, Eduardo Cabello 6,
36208, Vigo
IMPRESIÓN (VEM2003-20021)
“Impacto del vertido de hidrocarburos del PREStige sobre la red trófica microbiana planctÓNica”.
Work programme 4: Impact on biologic systems. Impact assessment on biodiversity: population and communities distribution and abundance. Ecosystem restoration monitoring. Pelagic system.
Polycyclic Aromatic hydrocarbons (PAHs)
LMW
(2-3 days)
HMW
(9 days)
marine hydrocarbonoclastic bacteria
AlcanivoraxCycloclasticusOleiphilusOleispira
“professionals”
Marine bacteria degrading petroleum hydrocarbons
-Proteobacteria
Planococcus
G+ bacteria
LMW PAHs:Naphthalene
PhenanthreneAnthracene
Mesocosm experiment-IMPRESIÓN-1: Ría de Vigo, March 2005
Water filtered through 200 m
Temperature
10 ºC
Chlorophyll-a
≈5 g/l
1 L1 2 C2
platform
Bouzas bay
1.5m 3 H2 4 C1
5 H1 6 L2
empt
yC-Control L-Low PAHs concentration (6 g/L)H-High PAHs concentration (15 g/L)
Mesocosm experiment-IMPRESIÓN-1: Ría de Vigo, March 2005
The experiment lasted 9 days
Methods
-Bacterial abundance: Direct microscopy on polycarbonate filters (DAPI-staining)
-Bacterial production: Rates of protein synthesis with 3H-Leucine
-Bacterial community composition: Fluorescent In Situ Hybridization
-Proteobacteria (Alfa)
-Proteobacteria (Gamma)
Cytophaga-Flexibacter-Bacteroidetes (CTB)
Cycloclasticus spp. (Cypu)
Fluorescence In Situ Hybridization (FISH): fluorescence-labeled oligonucleotide probes targeting the small subunit rRNA of specific prokaryotic groups.
target
probe
10m
Lauderia annulata
Development and decay of a diatom bloom
Day
0 1 2 3 4 5 6 7 8 9
PA
Hs
conc
entr
atio
n (
g/l)
0
5
10
15
20
Day
0 1 2 3 4 5 6 7 8 9
Cyc
locl
astic
us s
pp.
abun
danc
e (1
04/m
l)
0,0
0,5
1,0
1,5
2,0
ControlHigh concentration
Day
0 1 2 3 4 5 6 7 8 9
Chl
orop
hyll-
a (
g/l)
0
2
4
6
8
10
12
14
ControlHigh concentration
PAHs addition
Day
0 1 2 3 4 5 6 7 8 9
Leu
upta
ke (
pM/h
)
10
100
1000Day
0 1 2 3 4 5 6 7 8 9
BA
(10
5 c
el/m
l)
2
4
6
8
10
12
14
ControlHigh concentration
Day 1-3: bacterial abundance decrease in all the mesocosms
Day 3: bacterial production is higher in H than in C
Day 4-8: bacterial abundance and production is lower in H than in C
Bacterial abundance and production
-No significant differences in bacterial composition between C and H mesocosms
-CTB and -proteobacteria dominate the bacterial community
-Cycloclasticus spp is undetectable.
Bacterial composition-Day 0
Alfa (20%) CTB (35%)
Gamma (10%) Cypu (<1%)
10m
Day 0
C H
%D
AP
I-st
ain
ed
cells
0
10
20
30
40
50
60 AlfaGammaCTBCypu
Control
-Total detection is low in both C and L mesocosms (<50%)
-Cycloclasticus spp comprise 7% of the total bacterial community in H mesocosms
Bacterial composition-Day 4
Alfa (10%) CTB (20%)
Gamma (20%) Cypu (7%)
10m
High
Day 4
C H
% D
AP
I-st
ain
ed
cells
0
10
20
30
40
50
60 AlfaGammaCTBCypu
**
Control High
CTB and AlfaDominate in C
Bacterial composition-Day 8
Alfa (30%) CTB (60%)
Gamma (15%) Cypu (n.d.)
Alfa (15%) CTB (50%)
Gamma (30%) Cypu (1%)
10m 10m
Day 8
C H
% D
AP
I-st
aine
d ce
lls
0
10
20
30
40
50
60 AlfaGammaCTBCypu
CTB and GammaDominate in H
* *
Day
0 1 2 3 4 5 6 7 8 9
PA
Hs
conc
entr
atio
n (
g/l)
0
5
10
15
20
Day
0 1 2 3 4 5 6 7 8 9
Cyc
locl
astic
us s
pp.
abun
danc
e (1
04/m
l)
0,0
0,5
1,0
1,5
2,0
ControlHigh concentration
PAHs concentration and Cycloclasticus abundance
PAHs addition
Day 1-4: PAHs concentration rapidly decrease, and Cycloclasticus abundance increase
Day 4-8: PAHs concentration drop to the levels in C, and Cycloclasticus abundance decrease
Summary
-Most of the PAHs disappeared within 3 days after the fuel addition.
-Cycloclasticus abundance rapidly increased after the PAHs addition, reaching its maximum 3 days after the oil addition.
-Cycloclasticus growth appears to be related to LMW PAHs degradation.
-The bacterial community composition significantly changed 8 days after the oil addition: the -Proteobacteria subclass predominate over -Proteobacteria subclass.