title: Symbiosis insights through metagenomic analysis of a microbial consortium.
abstract: Symbioses between bacteria and eukaryotes are ubiquitous, yet our understanding of the interactions driving these associations is hampered by our inability to cultivate most host-associated microbes. Here we use a metagenomic approach to describe four co-occurring symbionts from the marine oligochaete Olavius algarvensis, a worm lacking a mouth, gut and nephridia. Shotgun sequencing and metabolic pathway reconstruction revealed that the symbionts are sulphur-oxidizing and sulphate-reducing bacteria, all of which are capable of carbon fixation, thus providing the host with multiple sources of nutrition. Molecular evidence for the uptake and recycling of worm waste products by the symbionts suggests how the worm could eliminate its excretory system, an adaptation unique among annelid worms. We propose a model that describes how the versatile metabolism within this symbiotic consortium provides the host with an optimal energy supply as it shuttles between the upper oxic and lower anoxic coastal sediments that it inhabits.
authors.affiliation: DOE Joint Genome Institute, Walnut Creek, California 94598, USA.
authors.forename: Tanja
authors.initials: T
authors.lastname: Woyke
authors.forename: Hanno
authors.initials: H
authors.lastname: Teeling
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Ivanova
authors.forename: Marcel
authors.initials: M
authors.lastname: Huntemann
authors.forename: Michael
authors.initials: M
authors.lastname: Richter
authors.forename: Frank Oliver
authors.initials: FO
authors.lastname: Gloeckner
authors.forename: Dario
authors.initials: D
authors.lastname: Boffelli
authors.forename: Iain J
authors.initials: IJ
authors.lastname: Anderson
authors.forename: Kerrie W
authors.initials: KW
authors.lastname: Barry
authors.forename: Harris J
authors.initials: HJ
authors.lastname: Shapiro
authors.forename: Ernest
authors.initials: E
authors.lastname: Szeto
authors.forename: Nikos C
authors.initials: NC
authors.lastname: Kyrpides
authors.forename: Marc
authors.initials: M
authors.lastname: Mussmann
authors.forename: Rudolf
authors.initials: R
authors.lastname: Amann
authors.forename: Claudia
authors.initials: C
authors.lastname: Bergin
authors.forename: Caroline
authors.initials: C
authors.lastname: Ruehland
authors.forename: Edward M
authors.initials: EM
authors.lastname: Rubin
authors.forename: Nicole
authors.initials: N
authors.lastname: Dubilier
mesh_terms: D000818:Animals; D002244:Carbon / Q000378:metabolism; D004063:Digestion / Q000502:physiology; D004734:Energy Metabolism; D004777:Environment; D023281:Genomics; D008829:Microbiology; D008954:Models, Biological; D009835:Oligochaeta / Q000382:microbiology* / Q000502:physiology*; D020560:Proteobacteria / Q000235:genetics* / Q000378:metabolism*; D013559:Symbiosis / Q000235:genetics* / Q000502:physiology*
chemical_list: D002244:Carbon