Microbial Processes in the Anoxic Cariaco Basin Microbial Processes in the Anoxic Cariaco Basin

Prof . Gordon TaylorProf . Gordon TaylorMarine Sciences Research CenterMarine Sciences Research Center

Stony Brook UniversityStony Brook UniversityNew York, USANew York, USA

microbes (# L-1)2 4 6

flagellates x106

prokaryotes x108

production (gC L-1d-1)2 4 6

chemoautotrophicheterotrophic

H2S (mol L-1)

10 20 30

H2S

A B C

O2 (mol L-1)50 100 150 200

dept

h (m

)0

200

400

600

800

1000

1200

O2

Typical vertical distributions of properties and activities. Note relative rates of chemoauto- and heterotrophs in panel C. (currently have 112 bact and 29 flag profiles)

CAR-32(7 Jul 98)

water density nearly homogenous below 200 mwater density nearly homogenous below 200 m

Note: bottom temp > 17°CNote: bottom temp > 17°C

light scattering particle layerslight scattering particle layers

pMn (nM)0 25 50 75

NO2- (M)

0.0 0.1 0.2

Mn2+ (nM)

0 200 400 600

NH4+ (M), NO3

- (M)0 5 10 15 20

Dep

th (

m)

0

100

200

300

400

500

1000

1200

Fe2+ (nM)

0 200 400 600

pFe (nM), O2 (M)0 50 100 150 200

NH4+

NO3-

NO2-

Mn2+

pMn

pFe

Fe2+

O2

CAR-32(7 Jul 98)

(Taylor et al. 2001)

nitrification?

Guilds organized by chemical gradients, not water density

0 2 4 6 8

A B

( x 109 )

0.0 0.5 1.0 4.0

VLP L-1, prokaryotes L-1

1 2 3 4D

epth

(m

)0

100

200

300

400

500

1000

1200

vlp ( x1010 )prokaryotes ( x108 )

heterotrophic bacterial production, BNP ( g C L-1 d-1 )

0 1 2 3

bnp

Vertical distributions of viruses (VLP) closely correlated w/ prokaryotic abundances & activity (Taylor et al. 2003)

0 1 20 1 20 1 2

Dep

th (

m)

100

200

300

400

500

0 1 2

dark DIC assimilation ( M C d-1 )0 1 2 0 1 2 0 1 2

9 Nov 96 8 May 97 14 Nov 97 10 Mar 98 7 Jul 98 7 Nov 98 7 May 99

0 200 20 0 20 0 20

O2 ( M ), H2S ( M )

O2

H2S

0 200 20 0 20

cap

Chemoautotrophic production peaks always apparent below O2/H2S interface (Taylor et al. 2001) (currently have 16 such profiles)

(Madrid et al. 2001)

Affiliation of 16S rDNA sequences from the Cariaco Basina

identified in 320, 500 and 1310 m libraries with major taxa.Phylogenetic Affiliation % in library

November 1996Nov1997

320m 500m 1310m 310 mArchaea 0 1.97 13.11 0 Crenarchaeota 0 0 1.64 0 Euryarchaeota 0 1.96 11.47 0

Bacteria 100 98.03 86.89 100 Candidate division OP3 1.67 3.94 8.19 0 Candidate division OP8 0 0 1.64 0 Planctomyces 0 0 4.92 0 Fibrobacter and relatives 0 19.6 1.64 0 Flexibacter-Cytophaga-Bacteroides

0 3.94 6.56 0

Verrumicrobiales 0 1.97 0 0 High GC Gram + bacteria. 0 3.94 8.2 0Proteobacteria [98.33] [64.64] [55.74] [100] New candidate subdivisions (1.67) (3.97) (3.28) 0 -proteobacteria (0) (0) (0) (4.83) -proteobacteria (0) (0) (1.64) (0) -proteobacteria (1.67) (23.48) (31.15) (87.11) Unknown 1.67 0 4.92 6.45Gamma symbiont relatives 0 0 0 80.66 Pseudoalteromonas (PVB18) 0 11.74 19.37 0 Photobacterium spp. 0 0 1.64 0Other potential fermenters 0 11.74 4.92 0-proteobacteria (1.67) (17.62) (11.48) (8.06) Unknown 1.67 3.94 0 6.45 Desulfovibrio sp. (SB-30) 0 5.85 6.56 0 Desulfonema sp. (RFLP25) 0 0 1.64 0 Desulfuromonas sp. 0 1.97 0 0 Other potential SO4 reducers 0 5.86 3.28 1.61-proteobacteria (93.32) (17.6) (8.19) (0) Epsilon symbiont relatives 88.31 14.5 8.19 0 'Thiomicrospira' spp. 1.67 1.97 0 0 Arcobacter spp. 3.34 0 0 0

a chimeric sequences were excluded from the analysis.

redoxcline 16S rDNA library dominated -proteobacteria

(Archaea uncommon in libraries)

(Madrid et al. 2001)

-proteobacterial symbiont relatives putatively w/ S-metabolism

16S rDNA library

Cariaco Cariaco Black Sea Black Sea

Similar to Similar to hydrothermal vents, hydrothermal vents, --proteobacteria are proteobacteria are most common most common organisms at boundary organisms at boundary where sulfide meets where sulfide meets oxygen (Lin et al. oxygen (Lin et al. submitted AEM). Group submitted AEM). Group tends to be chemo-tends to be chemo-autotrophic w/ sulfur autotrophic w/ sulfur metabolism.metabolism.

EPS549-positive cellsEPS549-positive cells

OO22/H/H22S interfaceS interface

0 20 40 60

0 10 20 30

dept

h (m

)

200

400

600

800

1000

1200

-proteobacteria (% of DAPI)0 10 20 30

H2S (M)

0 20 40 60

0 10 20 30

0 20 40 60

8 May 03(CAR-89)

20 Jan 04(CAR-96)

18 May 04(CAR-100)

O2

H2S

EP

S54

9-po

sitiv

e ce

lls

CARD-FISH time series for -proteobacteria [Lin & Taylor unpubl. data]

Improved detection provided by CARD-FISH (catalyzed reporter deposition) using modified protocols of Pernthaler and others [Lin et al. AEM submitted]

0 20 40 60

0 10 20 30 40

dept

h (m

)

200

400

600

800

1000

1200

Archaea (% of DAPI)0 10 20 30 40

H2S (M)

0 20 40 60

0 10 20 30 40

0 20 40 60

8 May 03(CAR-89)

20 Jan 04(CAR-96)

18 May 04(CAR-100)

O2

H2S

AR

CH

915-

posi

tive

cells

CARD-FISH time series for Archaea [Lin & Taylor unpubl. data]

(Stoeck, Taylor & Epstein, AEM 2003)

18S rDNA libraries includephylotypes with close affinitiesto known ciliates that:

possess symbionts and hydrogenosomes

occupy low O2 habitats

(Stoeck, Taylor & Epstein, AEM 2003)

Novel “class-level” clade of ciliates suggested from 18S rDNA libraries harvestedfrom 900 m – “cryptic diversity”w/i anaerobic protists

(Madrid 2000 & Lin unpubl data)(Madrid 2000 & Lin unpubl data)

MnO2 reduced at expense of S2O3

Classical enrichment cultures revealed:Classical enrichment cultures revealed:

S2O3 oxidizing / MnO2 reducers H2S oxidizing / NO3 reducers S0 & S2O3 disproportionaters no aerobic sulfide oxidizers– none identified yet!

Cariaco Participants

• Time SeriesTime Series – F. Muller-Karger (USF), R. Thunell (USC), M. – F. Muller-Karger (USF), R. Thunell (USC), M.

Scranton & G. Taylor (SBU)Scranton & G. Taylor (SBU)

• Prokaryotic ObservatoryProkaryotic Observatory – A. Chistoserdov (ULL), G. Taylor – A. Chistoserdov (ULL), G. Taylor

(SBU), M. Scranton (SBU), P. Suarez (U Simon Bolivar) (SBU), M. Scranton (SBU), P. Suarez (U Simon Bolivar)

• Protistan ObservatoryProtistan Observatory – S. Epstein (NEU), G. Taylor (SBU), – S. Epstein (NEU), G. Taylor (SBU),

V. Edgcomb (WHOI), S. Sievert (WHOI), D. Patterson V. Edgcomb (WHOI), S. Sievert (WHOI), D. Patterson

(MBL), P. Suarez (U Simon Bolivar) (MBL), P. Suarez (U Simon Bolivar)

Support: NSF ChemOce- OCE-0326175, OCE01-18491, OCE97-30278

NSF Molec. Cell Biol - MCB-0347811, MCB-0348442

FONACIT (Venezuela) - #2000001702