Metagenomic investigation of the geologically unique Hellenic Volcanic Arc reveals a distinctive ecosystem with unexpected physiology.
Hydrothermal vents represent a deep, hot, aphotic biosphere where chemosynthetic primary producers, fuelled by chemicals from Earth's subsurface, form the basis of life. In this study, we examined microbial mats from two distinct volcanic sites within the Hellenic Volcanic Arc (HVA). The HVA is geologically and ecologically unique, with reported emissions of CO2 -saturated fluids at temperatures up to 220°C and a notable absence of macrofauna. Metagenomic data reveals highly complex prokaryotic communities composed of chemolithoautotrophs, some methanotrophs, and to our surprise, heterotrophs capable of anaerobic degradation of aromatic hydrocarbons. Our data suggest that aromatic hydrocarbons may indeed be a significant source of carbon in these sites, and instigate additional research into the nature and origin of these compounds in the HVA. Novel physiology was assigned to several uncultured prokaryotic lineages; most notably, a SAR406 representative is attributed with a role in anaerobic hydrocarbon degradation. This dataset, the largest to date from submarine volcanic ecosystems, constitutes a significant resource of novel genes and pathways with potential biotechnological applications.
Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece.
Anastasis
A
Oulas
Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece.
Paraskevi N
PN
Polymenakou
Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.
Rekha
R
Seshadri
Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.
H James
HJ
Tripp
Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece.
Manolis
M
Mandalakis
Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.
A David
AD
Paez-Espino
Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.
Amrita
A
Pati
Los Alamos National Laboratory, Los Alamos, NM, USA.
Patrick
P
Chain
National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Athens, Greece.
Paraskevi
P
Nomikou
Graduate School of Oceanography, University of Rhode Island, Kingston, RI, USA.
Steven
S
Carey
National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Athens, Greece.
Stephanos
S
Kilias
Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece.
Christos
C
Christakis
Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece.
Georgios
G
Kotoulas
Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece.
Antonios
A
Magoulas
Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.
Natalia N
NN
Ivanova
Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.|Department of Biological Sciences, King Abdulaziz, Jeddah, Saudia Arabia.
Nikos C
NC
Kyrpides
D001105:Archaea / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D001419:Bacteria / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D017753:Ecosystem; D005844:Geology; D060086:Hydrothermal Vents / Q000382:microbiology*; D056186:Metagenomics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013696:Temperature
D012336:RNA, Ribosomal, 16S