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Appl Environ Microbiol, January 1998, p. 370-375, Vol. 64, No. 1
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Stable-Carbon-Isotope Composition of Fatty Acids in
Hydrothermal Vent Mussels Containing Methanotrophic and Thiotrophic
Bacterial Endosymbionts
David W.
Pond,1,2,*
Michael V.
Bell,1
David R.
Dixon,2
Anthony E.
Fallick,3
Michel
Segonzac,4 and
John R.
Sargent1
NERC Unit of Aquatic Biochemistry, Department
of Biological and Molecular Sciences, University of Stirling,
Stirling FK9 4LA,1
Plymouth Marine
Laboratory, Plymouth PL1 3DH,2 and
Isotope Geosciences Unit, SURRC, East Kilbride, Glasgow
G75 OQF,3 United Kingdom, and
IFREMER,
F-29280 Plouzané, Brest, France4
Received 26 August 1997/Accepted 31 October 1997
 |
ABSTRACT |
Fatty acid biomarker analysis coupled with gas
chromatography-isotope ratio mass spectrometry was used to confirm the
presence of methanotrophic and thiotrophic bacterial endosymbionts in
the tissues of a hydrothermal vent mussel (Bathymodiolus
sp.), collected from the Menez Gwen vent field on the mid-Atlantic
ridge. Monounsaturated (n-8) fatty acids, which are diagnostic of
methanotrophic bacteria, were detected in all three types of tissues
examined (gill, posterior adductor, and mantle), although levels were
highest in gill tissues where the bacteria were found.
Stable-carbon-isotope compositions (
-13C per mille
relative to that of Peedee belemnite) of fatty acids for all three
tissues ranged from 
24.9 to 34.9
, which encompasses the range
predicted for both thiotroph- and methanotroph-based nutrition. The
data suggest that these thio- and methanotrophic bacterial
endosymbionts are equally important in the nutrition of the vent mussel
at this particular vent site.
| |
TEXT |
Symbioses between deep-sea bivalves
and either thio- (4, 18) or methanotrophic bacteria (5,
8, 18) have been widely reported. More recently, it has been
established that some bivalves from hydrothermal vents on the
mid-Atlantic ridge (MAR) contain both types of symbiotic bacteria in
their gills (6), and this has been interpreted as being
advantageous for the bacteria in colonizing a wider range of
geochemical environments (17).
Fatty acid biomarkers, diagnostic for thio- and methanotrophic
bacteria, have proven to be a useful tool in the study of host-symbiont relationships in deep-sea faunas (33-35). When such
analyses are coupled with isotope ratio mass spectrometry (IRMS), the
technique becomes even more powerful and it may be possible to identify both the source of carbon and trophic transfer within
chemoautolithotrophic ecosystems (1, 16, 28, 33, 36).
In contrast to deeper MAR sites (3,000 to 3,650 m), where alvinocaridid
shrimps tend to dominate (38, 41), the Menez Gwen (850 m)
and Lucky Strike (1,650 m) vent fields at the Azores triple junction
are dominated by an undescribed bivalve mussel,
Bathymodiolus sp. (14, 21, 42).
Stable-carbon-isotope (-13C) values of 24.1 for the
mussels at Lucky Strike led to speculation that methanotrophic
metabolism could be a significant source of nutrition (17).
In the present study we conducted gas chromatography (GC)-IRMS analysis
of various tissue types in the mussel species from Menez Gwen in an
attempt to establish, from the stable-isotope compositions of their
fatty acid biomarkers, the relative importance of thio- and
methanotrophic bacterial endosymbionts in its nutrition.
Station location and description.
Three specimens of
Bathymodiolus sp. were collected from the same locality by
using the IFREMER submersible vessel Nautile, during the
DIVA 2 cruise (dive PL 16), in June 1994 from the Menez Gwen
hydrothermal vent field at 37°50'N, 31°31'W (850 m) on the MAR. As
with other vent sites, the mussels at Menez Gwen were found in areas
typified by diffuse-flow, low-temperature venting. A full description
of the Menez Gwen site and ecology is given in references 14,
21, and 22. Mussels were frozen at
70°C shortly after collection. Specimens were measured (greatest
anterior-to-posterior-shell lengths) and weighed in the laboratory
before removal of mantle, gill, and posterior adductor tissues. Thin
films of dark-brown epibiotic material which coated the outside of the
shells were scraped off with a scalpel for analysis.
Lipid analyses.
Immediately after dissection, mussel tissue
samples and epibiotic material were homogenized in chloroform-methanol
(2:1, vol/vol) before being filtered through a prewashed
(chloroform-methanol [2:1, vol/vol]) Whatman no. 1 paper filter.
Total lipid was extracted by following the method of Folch et al.
(20) and dried under nitrogen. Aliquots of total lipid were
transesterified in methanol containing 1.5% (vol/vol) sulfuric acid
for 16 h at 50°C (9), and the fatty acid methyl
esters were purified by thin-layer chromatography. Component fatty acid
methyl esters were analyzed by GC on a Canberra 436 GC fitted with a
BP20 fused silica capillary column (50 m by 0.32 mm, inside diameter;
SGE) with hydrogen as a carrier gas.
GC-MS.
To reduce coelution of fatty acids, methyl esters were
first separated into saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), diunsaturated fatty acid (DUFA), and polyunsaturated fatty
acid (PUFA; three or more double bonds) fractions by argentation high-performance thin-layer chromatography with hexane-diethyl ether
(90:10, vol/vol) (43). MUFA positional isomers were
determined with dimethyl disulfide adducts (30) and the
double-bond positions of DUFAs and PUFAs as both diethylamide
(31) and picolinyl (10) derivatives with a Fisons
MD 800 GC-MS. The GC was fitted with a DB-5MS column (15 m by 0.25 mm,
inside diameter; J & W Scientific) and the MS was operated in the
electron-impact-negative mode with helium as the carrier gas.
GC-IRMS.
Stable-carbon-isotope ratios
(13C/12C) were measured by GC-combustion IRMS
with a VG Isochrom II instrument equipped with a column similar to that
described above (15). Conventional quartz closed-tube combustion (39) was employed to determine the
-13C composition of the methanol used to prepare the
methyl esters, and the contribution of derivatized carbon to specific
fatty acids was calculated as described previously (33).
The three mussels used in this study had wet masses, including their
shells, of 17.5, 12.6, and 10.3 g. Maximum
anterior-to-posterior-shell dimensions of these same specimens were
6.7, 5.4, and 4.9 cm, respectively.
Fatty acid composition.
Overall, the fatty acid compositions
of gill, mantle, and posterior adductor tissues were similar and
dominated by the SFA 16:0 and (n-7) MUFAs (Table
1; Fig. 1).
Lesser amounts of 16:1(n-9) and 16:1(n-8) MUFAs were also detected,
although these could not be adequately resolved for accurate
quantification by GC and hence had to be combined (Table 1). Notably,
there were significantly higher proportions of 16:1(n-9+n-8) and
20:1(n-13) MUFAs in the gill tissue fractions than in mantle and
adductor tissue fractions (analysis of variance [ANOVA],
P < 0.001 and P < 0.01, respectively) (Fig. 1). Gill tissue also contained a significantly lower proportion of 18:1(n-7) than mantle and adductor tissues (ANOVA, P < 0.001 and P < 0.003, respectively).
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FIG. 1.
Proportions of different groups of fatty acids from gill
tissue containing endosymbionts (a), mantle tissue (b), posterior
adductor tissue (c), and epibiotic material (d). Thiotrophic and
methanotrophic fatty acid markers comprise only those fatty acids
considered to be specific to either group (Table 1).
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|
The non-methylene-interrupted dienes (NMIDs) 20:2
5, 11; 20:2
5,
13; and 22:2
7, 15 were moderately abundant in all three
tissues
and, when combined, accounted for 8.2 to 11.4% of the
total fatty
acids (Fig.
1). Gill tissue contained significantly
higher proportions
of the triunsaturated fatty acid 18:3(n-7)
than mantle and adductor
tissues (ANOVA,
P < 0.001, and
P < 0.004,
respectively) (Table
1), while 20:3(n-7) was only significantly
higher in gill tissue than in mantle tissue (ANOVA,
P < 0.03).
The PUFAs 20:5(n-3) and 22:6(n-3) were detected only in
posterior
adductor tissue in very small amounts (Table
1; Fig.
1).
Compared to the mussel tissues, epibiotic material from the shell
surfaces contained larger amounts of SFAs (14:0, 16:0, and
18:0)
and smaller amounts of NMIDs and 20:3(n-7) (Table
1; Fig.
1). When
combined, the (n-13) and (n-9+n-8) MUFAs were present
in proportions
comparable to those observed in mussel tissue and
accounted for
approximately 16% of both mussel tissue and epibiotic
fatty acids.
20:5(n-3) was also detected in the epibiotic fatty
acids, although in
very small amounts (Table
1).
Stable-isotope composition.
The methanol used to prepare
methyl esters had a -13C value of 41.8 relative to
that of Peedee belemnite (PDB), and GC-IRMS values of fatty acids were
corrected (33). Mean stable-carbon-isotope compositions
(-13C per mille relative to that of PDB) of fatty acids
in the mussel tissues ranged from 24.9 for the NMID 20:2 5,11
to 34.9 for 14:0 (in gill tissue), although the majority of fatty
acids were in the general range 28.5 to 32.0 (Table
2). Although stable-isotope ratios for
specific fatty acids in the three tissue types were similar, the gill
SFAs 14:0, 16:0, and 18:0 were all significantly 12C
enriched compared to the corresponding fatty acids from mantle and
adductor tissues (ANOVA, P < 0.05) (Table 2).
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TABLE 2.
-13C values of fatty acids in various
tissues and epibiotic material of the hydrothermal vent mussel
Bathymodiolus sp.
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|
Stable-isotope compositions of epibiont fatty acids were within the
range of values determined for the mussel tissues (
26.0
to
30.1
)
(Table
2). The fatty acids 14:0, 16:1(n-9+n-8+n-7),
and 18:1(n-7) had
significantly higher levels of
-
13C in epibiotic
material than in all mussel tissues, while 16:0
was only significantly
13C enriched compared to gill tissue (ANOVA,
P < 0.01).
In order to gain further information on the contribution of the
thiotrophic and methanotrophic endosymbionts to the nutrition
of the
mussel, the stable-carbon-isotope composition of total
free fatty acids
of mantle tissue was measured; the value was
determined to be
28.3
by closed-tube combustion. Mantle tissue
is not known to contain
endosymbionts, and all fatty acids contained
in this tissue can be
attributed to the mussel.
Discussion.
The occurrence of deep-sea invertebrate-bacterium
symbioses has previously been well-established by techniques such as
electron microscopy (6, 18, 40), enzyme assays diagnostic of
particular bacterial symbionts (6, 17, 18), and analyses of
bulk-carbon-isotope ratios (6, 19). However, these
techniques offer limited quantitative information and do not
discriminate between material derived from the host, bacterial
endosymbiont(s), and exogenous sources. By contrast, analyses of fatty
acid biomarkers often allow a fuller evaluation of host-symbiont energy
relationships and carbon sources (23, 26, 33, 34, 36).
Electron microscopy of gill tissues from mussels at the adjacent Lucky
Strike site has indicated the presence of endosymbiotic
bacteria with
stacked intracellular membranes, which are characteristic
of type I
methanotrophs (
17). Mussels at Menez Gwen also appear
to
have endosymbiotic bacteria with stacked intracellular membranes,
as
was confirmed by the detection of 16:1(n-8), a fatty acid which
is
considered to be a definitive marker for this bacterial group
(
3,
29). Furthermore, the occurrence of this same fatty acid
in all
tissues, gill, mantle, and adductor muscle, confirmed that
(i)
methane-oxidizing metabolism is active in the mussel and (ii)
the type
I methanotroph-derived fatty acids contribute directly
to the overall
nutrition of the bivalve host. It is notable that
the 18:1(n-8) fatty
acid, which is diagnostic of type II methanotrophic
bacteria (
3,
29), was also detected in all the three tissue
types. It is
established that 16:1(n-7) is a major component of
thiotrophic
bacteria, and hence this fatty acid has been used
as a marker for the
presence and abundance of thiotrophic bacteria
both in sediments and
deep-sea invertebrates (
24,
35). However,
as 16:1(n-7) can
also be a major component of both type I methanotrophs
and conventional
heterotrophic bacteria (
3,
29,
37), its
use as a marker for
thiotrophs is not definitive. Similarly, 18:1(n-7)
has been reported as
indicative of the presence of thiotrophic
bacteria (
24), but
this fatty acid is also a substantial component
of type II
methanotrophs (
3). Thiotrophic bacteria have been
detected
previously in the gill tissues of mussels from the adjacent
Lucky
Strike vent field (
6,
17,
41) and are likely to be
present
in the animals analyzed in the present study, but the
low proportions
of 18:1(n-7) in the gill tissues of the Menez
Gwen mussels (2.4%) does
allow the conclusion that type II methanotroph
fatty acids contribute
in only a limited way to the overall nutrition
of the mussel. The
larger amounts of 18:1(n-7) in mantle and adductor
tissues (7 to 8%)
may indicate active elongation of 16:1(n-7)
by the host species,
although the presence of a functional gut
(
28) makes an
exogenous bacterial source also a possibility.
The exceptionally low levels of the PUFAs 20:5(n-3) and 22:6(n-3) in
all samples implies that (i) there is not a significant
source of these
compounds at Menez Gwen, either from the endosymbionts
or from
suspended particles, and (ii) these are not essential
fatty acids for
the mussel, as they are for higher marine vertebrates
and possibly
hydrothermal vent shrimps (
32-34). It has been proposed
that animals whose diets predominantly consist of bacteria, i.e.,
diets
rich in 16:0, 16:1(n-7), and 18:1(n-7) fatty acids, while
being
relatively deficient in (n-3) PUFAs, produce NMIDs from
monenoic fatty
acids (
2,
27) which effectively substitute
for the low
levels of (n-3) PUFAs. The presence of circa 10% NMIDs
in mussel
tissues is consistent with this hypothesis. The higher
levels of the
triunsaturated fatty acids 18:3(n-7) and 20:3(n-7)
in gill tissue
suggest that bacterial symbionts may be the source
of these compounds.
Several studies have demonstrated that thiotrophic
bacteria are capable
of synthesizing polyunsaturated fatty acids
(
25,
34),
although this ability has not been identified to
any extent in
methanotrophs (
3,
29).
The fatty acid profile of the epibiotic material, while exhibiting
large amounts of (n-8) MUFAs, contained substantially higher
levels of
the SFAs 14:0, 16:0, and 18:0. This is consistent with
the epibiotic
samples comprising predominantly detrital material,
since these fatty
acids are least prone to auto-oxidation and
tend to accumulate in
marine sediments. Furthermore, the detection
of (n-8) and NMID fatty
acids, albeit in small amounts, suggests
this detrital material is
derived from the mussel, most probably
via feces and pseudofeces.
However, it is possible that some of
the epibiotic fatty acids
originated from bacteria living on the
shell, a substratum which is
known to be colonized by methanotrophs
(
12).
Different groups of chemolithotrophic bacteria (thio- and
methanotrophs) associated with hydrothermal ecosystems utilize
different
carbon sources with distinct carbon isotope ratios.
Furthermore,
these different bacterial groups utilize different enzyme
systems
for carbon fixation which discriminate by various degrees
against
13C. Thiotrophic bacteria oxidize hydrogen sulfide
and utilize the
energy released to fix carbon dioxide into organic
compounds.
Similarly, methanotrophs also use a reduced compound as an
energy
source, in this case methane, which they also use as a carbon
source (
18). Thus, the isotope signatures in specific
carbon-containing
compounds can give a valuable indication as to the
nature of the
original carbon source and the organism(s) responsible
for their
synthesis.
The carbon isotope ratio of methane in the seawater at Menez Gwen has
recently been determined to be circa
13
(
7), a
value
which is also within the range reported for thiotrophs (
11).
Methanotrophic bacteria in deep-sea bivalves discriminate against
13CH
4 by approximately 6 to 12
(
8), and as lipid is isotopically
lighter than total organic
carbon by 3
(due to discrimination
against
13C during
the synthesis of acetyl coenzyme A by pyruvate decarboxylase
[
13]), we can predict that fatty acids derived from a
methane
carbon source would have isotope values in the range
22 to
28
.
This range agrees well with the value of
24.1
determined
previously
from a total carbon analysis of mussels from Lucky Strike,
which
also contain methanotrophic and thiotrophic endosymbionts
(
17).
In contrast, the carbon isotope ratio of hydrothermal
bivalves
containing only thiotrophic endosymbionts is usually somewhat
lower, with
-
13C values typically in the range
30 to
36
(
6,
11,
19).
If first we consider gill tissue, where the endosymbionts are known to
be located (
17), it is apparent that the fatty acids
14:0,
18:0, 18:1(n-7), 20:1(n-7), 18:3(n-7), and 20:3(n-7) are
comparatively
depleted of
13C, which is consistent with a thiotrophic
source for these compounds.
By contrast, the fatty acids which are
markers for methanotrophs,
i.e., 16:1(n-9+n-8+n-7) and
18:1(n-13+n-9+n-8), are relatively
enriched with
13C and
are at the top end of the range predicted for a methanotrophic
carbon
source. Unfortunately, it was not possible to distinguish
the
individual MUFAs, as the GC-IRMS technique necessitates the
use of
helium as a carrier gas, thus reducing resolution. Therefore,
the
slightly higher than predicted isotope ratios for MUFAs suggest
that at
least a proportion of the (n-7) and (n-9) fatty acids
are synthesized
by the thiotrophic endosymbionts. The isotopically
light values for the
fatty acids 18:3(n-7) and 20:3(n-7) support
the earlier assertion that
these compounds are of thiotrophic
origin.
Although some fatty acids are characteristic of either a thio- or a
methanotrophic origin, others are synthesized by both
types of bacteria
and hence their isotope ratios should reflect
dual biosynthetic
pathways. Based on information from the literature
(
3,
6,
17,
28,
29) and data from the present study,
each fatty acid was assigned
a biomarker designation in accordance
with its origin (Table
1). It was
then possible to calculate
the potential minimum and maximum percent
contributions of the
two symbiont pathways to the overall host-symbiont
fatty acid
pool (Table
3). Minimum
estimates include only fatty acids which
are recognized specific thio-
or methanotroph markers and also
those fatty acids whose isotope ratios
are typical of one group
only. Maximum estimates for each group were
based on these same
fatty acids, plus those capable of being produced
by both symbiont
types. Clearly, the maximum value may exaggerate the
contributions
of those fatty acids which are synthesized by both
symbionts.
Given that the carbon isotope composition for total fatty
acids
in mantle tissue is
28.3
, i.e., a value midway between the
range
expected for thio- and methanotroph metabolism, it is reasonable
to conclude that the two types of symbiont are more or less equally
important for the nutrition of the mussel host at this particular
vent
site. Such nutritional plasticity clearly facilitates the
colonization
of more than one type of chemical environment (
17).
It may
explain the dominance of mussels at both Menez Gwen and
other
"shallow" sites on the MAR (e.g., Lucky Strike at 1,700
m),
where vent effluent is richer in methane than it is at deeper
sites and
where thiotrophic bacteria-shrimp symbioses dominate
(
33,
38,
41).
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TABLE 3.
Estimated minimum and maximum percent contributions of
thiotrophic and methanotrophic fatty acids to the mussel tissues
and epibiotic materiala
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ACKNOWLEDGMENTS |
We thank Anne-Marie Alayse (IFREMER, Brest, France), chief
scientist of the DIVA 2 cruise, for providing the mussel specimens. We
also thank C. Taylor for conducting GC-IRMS analysis and J. R. Dick for GC-MS analysis of fatty acids.
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FOOTNOTES |
*
Corresponding author. Mailing address: NERC Unit of
Aquatic Biochemistry, Department of Biological and Molecular Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom. Phone: 44 1786 473171. Fax: 44 1786 464994. E-mail:
dwp1{at}stirling.ac.uk.
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REFERENCES |
| 1.
|
Abrajano, T. A.,
D. E. Murphy,
J. Fang,
P. Comet, and J. M. Brooks.
1994.
13C/12C ratios in individual fatty acids of marine mytilids with and without bacterial symbionts.
Org. Geochem.
21:611-617.
|
| 2.
|
Ackman, R. G., and S. N. Hooper.
1973.
Non-methylene interrupted fatty acids in lipids of shallow-water marine invertebrates: a comparison of the two molluscs (Littorina littorea and Lunatia trisseriata) with the sand shrimp (Crangon septemspinous).
Comp. Biochem. Physiol. B
46:153-165.
|
| 3.
|
Bowman, J. P.,
J. H. Skerratt,
P. D. Nichols, and L. I. Sly.
1991.
Phospholipid fatty acid and lipopolysaccharide fatty acid signature lipids in methane-utilizing bacteria.
FEMS Microbiol. Ecol.
85:15-22.
|
| 4.
|
Cavanaugh, C. M.
1985.
Symbioses of chemoautotrophic bacteria and marine invertebrates from hydrothermal vents and reducing sediments.
Bull. Biol. Soc. Wash.
6:373-388.
|
| 5.
|
Cavanaugh, C. M.,
P. R. Levering,
J. S. Maki,
R. Mitchell, and M. E. Lidstrom.
1987.
Symbiosis of methylotrophic bacteria and deep-sea mussels.
Nature
325:346-348.
|
| 6.
|
Cavanaugh, C. M.,
C. O. Wirsen, and H. W. Jannasch.
1992.
Evidence for methylotrophic symbionts in a hydrothermal vent mussel (Bivalvia: Mytilidae) from the Mid-Atlantic Ridge.
Appl. Environ. Microbiol.
58:3799-3803[Abstract/Free Full Text].
|
| 7.
| Charlou, J. L., J. P. Donval, Y. Fouquet, E. Douville, J. Knoery, P. Jean-Baptiste, A. Dapoigny, and M. Stievenard. Geochemistry of fluids collected at Lucky Strike
(37°17'N) and Menez Gwen (37°50'N) hydrothermal fields, south of
the Azores Triple Junction on the Mid-Atlantic Ridge (DIVA 1 cruise May 1994). J. Geophys. Res., in press.
|
| 8.
|
Childress, J. J.,
C. R. Fisher,
J. M. Brooks,
M. C. Kennicutt II,
R. Bidigare, and A. E. Anderson.
1986.
A methanotrophic marine molluscan (Bivalvia, Mytilidae) symbiosis: mussels fueled by gas.
Science
233:1306-1308[Abstract/Free Full Text].
|
| 9.
|
Christie, W. W.
1982.
.
Lipid analyses, 2nd ed.
Pergamon Press, Oxford, United Kingdom.
|
| 10.
|
Christie, W. W., and K. Stefanov.
1987.
Separation of picolinyl ester derivatives of fatty acids by high-performance liquid chromatography for identification by mass spectrometry.
J. Chromatogr.
392:259-265.
|
| 11.
|
Conway, N.,
M. C. Kennicutt, and C. L. Van Dover.
1994.
Stable isotopes in the study of marine chemosynthetically-based ecosystems, p. 158-186. In
K. Lajtha, and R. Michener (ed.), Stable isotopes in ecology.
Blackwell Scientific Publications, New York, N.Y.
|
| 12.
|
de Angelis, M. A.,
A. L. Reysenbach, and J. A. Baross.
1991.
Surfaces of hydrothermal vent invertebrates: sites of elevated microbial CH4 oxidation activity.
Limnol. Oceanogr.
36:570-577.
|
| 13.
|
DeNiro, M. J., and S. Epstein.
1977.
Mechanisms of carbon isotope fractionation associated with lipid synthesis.
Science
197:261-263[Abstract/Free Full Text].
|
| 14.
|
Desbruyères, D.,
A.-M. Alyase,
E. Antoine,
G. Barbier,
F. Barriga,
M. Biscoito,
P. Briand,
J. P. Brulport,
T. Comtet,
L. Cornec,
P. Crassous,
P. Dando,
M. C. Fabri,
H. Felback,
F. Lallier,
A. Fiala-Médioni,
J. Gonçalves,
F. Mérnard,
J. Kerdoncuff,
J. Patching,
L. Saldanha, and P.-M. Sarradin.
1994.
New information on the ecology of deep-sea vent communities in the Azores triple junction area: preliminary results of the DIVA 2 cruise (31 May-4 July 1994).
Inter Ridge News
3:18-19.
|
| 15.
|
Eakin, P. A.,
A. E. Fallick, and J. Gerc.
1992.
Some instrumental effects in the determination of stable carbon isotope ratios by gas chromatography-isotope ratio mass spectrometry.
Chem. Geol.
101:71-79.
|
| 16.
|
Fang, J. P.,
T. A. Abrajano,
P. A. Comet,
J. M. Brooks,
R. Sassen, and I. R. MacDonald.
1993.
Gulf of Mexico hydrocarbon seep communities. XI. Carbon isotope fractionation during fatty acid biosynthesis of seep organisms and its implications for chemosynthetic processes.
Chem. Geol.
109:271-279.
|
| 17.
|
Fiala-Médioni, A.,
C. Cavanaugh,
P. Dando, and C. Van Dover.
1996.
Symbiotic mussels from the mid-Atlantic ridge: adaptations to trophic resources.
J. Conf. Abstr.
1:788.
|
| 18.
|
Fisher, C. R.,
J. J. Childress,
R. S. Oremland, and R. R. Bidigare.
1987.
The importance of methane and thiosulphate in the metabolism of the bacterial symbionts of two deep-sea mussels.
Mar. Biol.
96:59-71.
|
| 19.
|
Fisher, C. R.,
J. J. Childress,
A. J. Arp,
J. M. Brooks,
D. Distel,
J. A. Favuzzi,
H. Felbeck,
R. Hessler,
K. S. Johnson,
M. C. Kennicutt II,
S. A. Macko,
A. Newton,
M. A. Powell,
G. N. Somero, and T. Soto.
1988.
Microhabitat variation in the hydrothermal vent mussel, Bathymodiolus thermophilus, at the Rose Garden vent on the Galapagos Rift.
Deep-Sea Res.
35:1769-1791.
|
| 20.
|
Folch, J.,
N. Lees, and G. H. Sloan-Stanley.
1957.
A simple method for the isolation and purification of total lipid.
J. Biol. Chem.
226:497-509[Free Full Text].
|
| 21.
|
Fouquet, Y.,
J.-L. Charlou,
I. Costa,
J.-P. Donval,
J. Radford-Knoery,
H. Pellé,
H. Ondréas,
N. Louren,
M. Segonzac, and M. K. Tivey.
1994.
A detailed study of the Lucky Strike hydrothermal vent site and discovery of a new hydrothermal site: Menez Gwen; preliminary results of the DIVA 1 cruise (5-29 May 1994).
Inter Ridge News
3:14-17.
|
| 22.
|
Fouquet, Y.,
H. Ondréas,
J.-L. Charlou,
J.-P. Donval,
J. Radford-Knoery,
I. Costa,
N. Louren, and M. K. Tivey.
1995.
Atlantic larva lakes and hot vents.
Nature
377:201.
|
| 23.
|
Fullarton, J. G.,
P. R. Dando,
J. R. Sargent,
A. J. Southward, and E. C. Southward.
1995.
Fatty acids of hydrothermal vent Ridgeia piscesae and inshore bivalves containing symbiotic bacteria.
J. Mar. Biol. Assoc. U. K.
75:455-468.
|
| 24.
|
Guezennec, J., and A. Fiala-Medioni.
1996.
Bacterial abundance and diversity in the Barbados Trench determined by phospholipid analysis.
FEMS Microbiol. Ecol.
19:83-93.
|
| 25.
|
Jacq, E.,
D. Prieur,
P. Nichols,
D. C. White,
T. Porter, and G. G. Geesey.
1989.
Microscopic examination and fatty acid characterization of filamentous bacteria colonizing substrata around subtidal hydrothermal vents.
Arch. Microbiol.
152:64-71.
|
| 26.
|
Jahnke, L. L.,
R. E. Summons,
L. M. Dowling, and K. D. Zahiralis.
1995.
Identification of methanotrophic lipid biomarkers in cold-seep mussel gills: chemical and isotope analysis.
Appl. Environ. Microbiol.
61:576-582[Abstract].
|
| 27.
|
Klingensmith, J. S.
1982.
Distribution of non-methylene-interrupted dienoic fatty acids in polar lipids and triacylglycerols of selected tissues of the hardshell clam (Mercenaria mercenaria).
Lipids
17:976-981.
|
| 28.
|
Le Pennec, M.,
A. Donval, and A. Herry.
1990.
Nutritional strategies of the hydrothermal ecosystem bivalves.
Prog. Oceanogr.
24:71-80.
|
| 29.
|
Nichols, P. D.,
G. A. Smith,
C. P. Antworth,
R. S. Hanson, and D. C. White.
1985.
Phospholipid and lipopolysaccharide normal and hydroxy fatty acids as potential signatures for methane-oxidising bacteria.
FEMS Microbiol. Ecol.
31:327-335.
|
| 30.
|
Nichols, P. D.,
J. B. Gurkert, and D. C. White.
1986.
Determinations of monounsaturated fatty acid double-bond position and geometry for microbial monocultures and complex consortia by capillary GC-MS of their dimethyl sulphide adducts.
J. Microbiol. Methods
5:49-55.
|
| 31.
|
Nilsson, R., and C. Liljenberg.
1991.
The determination of double bond positions in polyunsaturated fatty acidsgas chromatography/mass spectrometry of the diethylamide derivative.
Phytochem. Anal.
2:253-259.
|
| 32.
|
Pond, D. W.,
D. R. Dixon, and J. R. Sargent.
1997.
Wax-ester reserves facilitate dispersal of hydrothermal vent shrimps.
Mar. Ecol. Prog. Ser.
146:289-290.
|
| 33.
|
Pond, D. W.,
D. R. Dixon,
M. V. Bell,
A. E. Fallick, and J. R. Sargent.
1997.
Occurrence of 16:2(n-4) and 18:2(n-4) fatty acids in the lipids of the hydrothermal vent shrimps Rimicaris exoculata and Alvinocaris markensis: nutritional and trophic implications.
Mar. Ecol. Prog. Ser.
156:167-174.
|
| 34.
|
Pond, D. W.,
M. Segonzac,
M. V. Bell,
D. R. Dixon,
A. E. Fallick, and J. R. Sargent.
1997.
Lipid and lipid carbon stable isotope composition of the hydrothermal vent shrimp Mirocaris fortunata: evidence for nutritional dependence on photosynthetically fixed carbon.
Mar. Ecol. Prog. Ser.
157:221-231.
|
| 35.
|
Pranal, V.,
A. Fiala-Medioni, and J. Guezennec.
1996.
Fatty acid characteristics in two symbiotic gastropods from a deep hydrothermal vent of the West Pacific.
Mar. Ecol. Prog. Ser.
142:175-184.
|
| 36.
|
Rieley, G.,
C. L. Van Dover,
D. B. Hedrick,
D. C. White, and G. Eglinton.
1995.
Lipid characteristics of hydrothermal vent organisms from 9°N East Pacific Rise, p. 329-342. In
L. M. Parson, C. L. Walker, and D. R. Dixon (ed.), Hydrothermal vents and processes.
The Geological Society, London, United Kingdom.
|
| 37.
|
Sargent, J. R.,
R. J. Parkes,
I. Mueller-Harvey, and J. Henderson.
1987.
Lipid biomarkers in marine ecology, p. 119-138. In
M. A. Sleigh (ed.), Microbes in the sea.
Ellis Horwood, Chichester, United Kingdom.
|
| 38.
|
Segonzac, M.,
M. De-Saint-Laurent, and B. Casanova.
1993.
L'énigme du comportement trophique des crevettes Alvinocarididae des sites hydrothermaux de la dorsale médio-atlantique.
Cah. Biol. Mar.
34:535-571.
|
| 39.
|
Sofer, Z.
1980.
Preparation of carbon dioxide for stable isotope analysis of petroleum fractions.
Anal. Chem.
52:1389-1391.
|
| 40.
|
Vacelet, J.,
A. Fiala-Médioni,
C. R. Fisher, and N. Boury-Esnault.
1996.
Symbiosis between methane-oxidizing bacteria and a deep-sea carnivorous cladorhizid sponge.
Mar. Ecol. Prog. Ser.
145:77-85.
|
| 41.
|
Van Dover, C.
1995.
Ecology of mid-Atlantic ridge hydrothermal vents, p. 257-294. In
L. M. Parson, C. L. Walker, and D. R. Dixon (ed.), Hydrothermal vents and processes.
The Geological Society, London, United Kingdom.
|
| 42.
|
Van Dover, C.,
D. Desbruyères,
M. Segonzac,
T. Comtet,
L. Saldanha,
A. Fiala-Médioni, and C. Langmuir.
1996.
Biology of the Lucky Strike site hydrothermal field.
Deep-Sea Res.
43:1509-1529.
|
| 43.
|
Wilson, R., and J. R. Sargent.
1992.
High-resolution separation of polyunsaturated fatty acids by argentation thin-layer chromatography.
J. Chromatogr.
623:403-407.
|
Appl Environ Microbiol, January 1998, p. 370-375, Vol. 64, No. 1
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
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