title: A novel archaeal species belonging to Methanoculleus genus identified via de-novo assembly and metagenomic binning process in biogas reactors.
abstract: Recently, a first comprehensive catalogue of microbial genomes populating biogas reactors treating manure and agro-industrial residues was determined by sequencing samples collected from 22 biogas reactors including laboratory and full scale. Among the archaeal community, one of the most abundant methanogens belongs to Methanoculleus genus and for this reason it was provisionally named Methanoculleus sp. DTU006. Its full length 16S rRNA sequence is 97% similar to Methanoculleus marisnigri JR1 and to Methanoculleus palmolei DSM 4273. Despite the high similarity of the 16S gene sequence, Average Nucleotide Identity calculation (ANI) calculated on all protein encoding genes indicated that the two most similar species, Methanoculleus bourgensis MS2Tand Methanoculleus sp. MAB1, are divergent enough to define Methanoculleus sp. DTU006 as new archaeal species. Its genome (2.15 Mbp) has an estimated completeness around 93%. Analysis of the metabolic pathways using KEGG confirmed that it is a hydrogenotrophic methanogen and therefore it is proposed the Candidatus status by naming it as "Candidatus Methanoculleus thermohydrogenotrophicum".
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark. Electronic address: panak@env.dtu.dk.
authors.forename: Panagiotis G
authors.initials: PG
authors.lastname: Kougias
authors.affiliation: Department of Biology, University of Padua, Via U. Bassi 58/b, 35121 Padova, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Campanaro
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark; Department of Agronomy, Food, Natural Resources, Animal and Environment (DAFNAE), University of Padua, Viale dell'Università, 16, 35020 Legnaro (Padova), Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Treu
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
authors.forename: Irini
authors.initials: I
authors.lastname: Angelidaki
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D019149:Bioreactors; D016000:Cluster Analysis; D058893:DNA Barcoding, Taxonomic; D020869:Gene Expression Profiling; D020745:Genome, Archaeal; D059014:High-Throughput Nucleotide Sequencing; D017404:In Situ Hybridization, Fluorescence; D056186:Metagenomics / Q000379:methods; D008697:Methane / Q000096:biosynthesis; D019638:Methanomicrobiaceae / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D010944:Plants / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D056804:Biofuels; D012336:RNA, Ribosomal, 16S; D008697:Methane
keywords: Anaerobic digestion; Archaea; Biogas; Hydrogenotroph; Metagenomic binning; Methanogen