||Postec Anne1, Lesongeur Francoise1, Pignet Patricia1, Ollivier B2, Querellou Joel1, Godfroy Anne1
||1 : IFREMER, Ctr Brest, Lab Microbiol Environm Extremes, UMR 6197, F-29280 Plouzane, France.
2 : Univ Aix Marseille 1, CESB ESIL, Lab IRD Microbiol Anaerobies, UR 101, F-13288 Marseille, France.
||Extremophiles (1431-0651) (Springer), 2007-11 , Vol. 11 , N. 6 , P. 747-757
|WOS© Times Cited
||Metabolic interactions, 16S rRNA gene, Thermophiles, Bioreactor, Continuous enrichment cultures, Deep sea hydrothermal vent, Microbial diversity
||The prokaryotic diversity of culturable thermophilic communities of deep-sea hydrothermal chimneys was analysed using a continuous enrichment culture performed in a gas-lift bioreactor, and compared to classical batch enrichment cultures in vials. Cultures were conducted at 60 degrees C and pH 6.5 using a complex medium containing carbohydrates, peptides and sulphur, and inoculated with a sample of a hydrothermal black chimney collected at the Rainbow field, Mid-Atlantic Ridge, at 2,275 m depth. To assess the relevance of both culture methods, bacterial and archaeal diversity was studied using cloning and sequencing, DGGE, and whole-cell hybridisation of 16S rRNA genes. Sequences of heterotrophic microorganisms belonging to the genera Marinitoga, Thermosipho, Caminicella (Bacteria) and Thermococcus (Archaea) were obtained from both batch and continuous enrichment cultures while sequences of the autotrophic bacterial genera Deferribacter and Thermodesulftitator were only detected in the continuous bioreactor culture. It is presumed that over time constant metabolite exchanges will have occurred in the continuous enrichment culture enabling the development of a more diverse prokaryotic community. In particular, CO2 and H-2 produced by the heterotrophic population would support the growth of autotrophic populations. Therefore, continuous enrichment culture is a useful technique to grow over time environmentally representative microbial communities and obtain insights into prokaryotic species interactions that play a crucial role in deep hydrothermal environments.