Free-Living and Symbiotic Bacterial Communities in Contrasting Hydrothermally Active Habitats

Simple item page
dc.contributor.authorForget, Nathalie
dc.contributor.supervisorJuniper, S. K.
dc.date.accessioned2013-08-29T22:43:08Z
dc.date.available2014-08-17T11:22:05Z
dc.date.copyright2013en_US
dc.date.issued2013-08-29
dc.degree.departmentDepartment of Biology
dc.degree.levelDoctor of Philosophy Ph.D.en_US
dc.description.abstractProkaryotic microorganisms, which are at the base of deep-sea hydrothermal vent food webs, adapt rapidly to environmental fluctuations. This study aimed at comparing bacterial communities in contrasting hydrothermal habitats to better understand compositional adaptations to local conditions. I first used small subunit (SSU) ribosomal RNA (rRNA) gene sequences to compare mat-forming bacterial communities associated with iron oxides at two hydrothermal vent sites on the Tonga Arc, southwest Pacific. Operational taxonomic units (OTUs), defined at 97% sequence similarity, were affiliated to a great diversity of autotrophic and heterotrophic groups. Metabolically diverse Gammaproteobacteria dominated the sample from Volcano 19, collected at 992 m depth. The sample from Volcano 1, collected at 197 m depth, was dominated by iron-oxidizing bacteria from the class Zetaproteobacteria. The depth of the sampling sites was proposed to explain clone library dissimilarities. In the following studies, I compared bacterial communities associated with the vestimentiferan tubeworm Ridgeia piscesae, a foundation species at the Juan de Fuca Ridge. Samples of the polychaete were collected from tubeworm habitats in contrasting flow regimes that influenced temperature and hydrogen sulphide concentrations. Free-living bacteria were analyzed using both sequencing and 454 pyrosequencing of the SSU rRNA gene. Statistical analyses suggested a predictable pattern of bacterial community composition for the two habitats, with higher proportions of sulphur and hydrogen oxidizers in High Flow and more heterotrophic groups in Low Flow environments. Temperature, available energy for metabolism, and stability of the habitat were suggested to explain these distinctive bacterial communities. Symbiotic assemblages were investigated using the same sequencing methods together with catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). Gammaproteobacteria dominated all sequence libraries, followed by Epsilonproteobacteria. CARD-FISH confirmed the co-occurrence of these groups within R. piscesae trophosomes. Statistical analyses indicated distinctive membership and structure of trophosome assemblages between sampling sites. Analysis of R. piscesae juvenile showed distinctive structural properties when compared to adult individuals, but similar membership, within sampling sites. These results suggested that the composition of trophosome assemblages might be affected by specific physical and chemical conditions at each vent site and that a selection process might occur during R. piscesae’s development.en_US
dc.description.proquestcode0410en_US
dc.description.proquestcode0416en_US
dc.description.proquestcode0329en_US
dc.description.proquestemailnathalieforget@gmail.comen_US
dc.description.scholarlevelGraduateen_US
dc.identifier.bibliographicCitationForget, N.L., Murdock, S.A., and Juniper, S.K. (2010) Bacterial diversity in Fe-rich hydrothermal sediments at two South Tonga Arc submarine volcanoes. Geobiology 8: 417-432.en_US
dc.identifier.bibliographicCitationForget, N.L., and Juniper, S.K. (2013) Free-living bacterial communities associated with tubeworm (Ridgeia piscesae) aggregations in contrasting diffuse flow hydrothermal vent habitats at the Main Endeavour Field, Juan de Fuca Ridge. MicrobiologyOpen 2: 259- 275.en_US
dc.identifier.urihttp://hdl.handle.net/1828/4869
dc.languageEnglisheng
dc.language.isoenen_US
dc.rights.tempAvailable to the World Wide Weben_US
dc.subjectHydrothermal ventsen_US
dc.subjectMicrobial Ecologyen_US
dc.subjectVestimentiferansen_US
dc.subjectRidgeia piscesaeen_US
dc.subjectTonga Arcen_US
dc.subjectJuan de Fuca Ridgeen_US
dc.subjectMolecular Biologyen_US
dc.subjectSSU rRNA geneen_US
dc.subjectSanger sequencingen_US
dc.subjectPyrosequencingen_US
dc.subjectCARD-FISHen_US
dc.subjectEndeavour Hydrothermal Ventsen_US
dc.subjectAxial Volcanoen_US
dc.titleFree-Living and Symbiotic Bacterial Communities in Contrasting Hydrothermally Active Habitatsen_US
dc.typeThesisen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Forget_Nathalie_PhD_2013.pdf
Size:
69.55 MB
Format:
Adobe Portable Document Format
Description:
PhD Dissertation
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.74 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Electronic Theses and Dissertations (ETD)
 
University of Victoria Libraries

We acknowledge and respect the Lək̓ʷəŋən (Songhees and Esquimalt) Peoples on whose territory the university stands, and the Lək̓ʷəŋən and W̱SÁNEĆ Peoples whose historical relationships with the land continue to this day.