Members of the uncultured bacterial candidate division WWE1 are implicated in anaerobic digestion of cellulose

Rim Driss Limam (1) , Rakia Chouari (2) , Laurent Mazéas (1) , Ting-Di Wu (3) , Tianlun Li (1) , Julien Grossin-Debattista (1) , Jean-Luc Guerquin-Kern (3) , Mouldi Saidi (4) , Ahmed Landoulsi (2) , Abdelghani Sghir (5) , T. Bouchez (1)

1 UR HBAN - Hydrosystèmes et Bioprocédés
2 Faculté des Sciences de Bizerte [Université de Carthage]
3 Imagerie intégrative de la molécule à l'organisme
4 Medical and Agricultural Applications of Nuclear Techniques
5 GENOSCOPE - Genoscope - Centre national de séquençage [Evry]

Clones of the WWE1 (Waste Water of Evry 1) candidate division were retrieved during the exploration of the bacterial diversity of an anaerobic mesophilic (35 +/- 0.5 degrees C) digester. In order to investigate the metabolic function of WWE1 members, a 16S rRNA gene -based stable isotope probing (SIP) method was used. Eighty-seven percent of 16S r rRNA gene sequences affiliated to WWE1 candidate division were retrieved in a clone library obtained after polymerase chain reaction (PCR) amplification of enriched DNA fraction from anaerobic municipal solid waste samples incubated with C-13-cellulose, at the end of the incubation (day 63) using a Pla46F-1390R primer pair. The design of a specific WWE1 probe associated with the fluorescence in situ hybridization (FISH) technique corroborated the abundant representation of WWE1 members in our C-13-cellulose incubations. Secondary ion mass spectrometry-in situ hybridization (SIMSISH) using an iodine-labeled oligonucleotide probe combined with high-resolution nanometer-scale SIMS (NanoSIMS) observation confirmed the isotopic enrichment of members of WWE1 candidate division. The C-13 apparent isotopic composition of hybridized WWE1 cells reached the value of about 40% early during the cellulose degradation process, suggesting that these bacteria play a role either in an extracellular cellulose hydrolysis process and/or in the uptake fermentation products.

Mots clés: DIGESTION ANAEROBIE; CELLULOSE

Domaines: Sciences de l'environnement

Rim Driss Limam, Rakia Chouari, Laurent Mazéas, Ting-Di Wu, Tianlun Li, et al.. Members of the uncultured bacterial candidate division WWE1 are implicated in anaerobic digestion of cellulose. MicrobiologyOpen, 2014, 3 (2), pp.157-167. ⟨10.1002/mbo3.144⟩. ⟨hal-01141717⟩