Kougias Panagiotis G, Campanaro Stefano, Treu Laura, Zhu Xinyu, Angelidaki Irini
Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
Department of Biology, University of Padua, Via U. Bassi 58/b, 35121 Padova, Italy.
Anaerobe. 2017 Aug;46:23-32. doi: 10.1016/j.anaerobe.2017.02.009. Epub 2017 Feb 17.
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 MS2 and 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".
最近，通过对从22个沼气反应器（包括实验室规模和全规模）采集的样本进行测序，确定了首个全面的、关于处理粪便和农业工业残留物的沼气反应器中微生物基因组的目录。在古菌群落中，最丰富的产甲烷菌之一属于甲烷袋状菌属，因此暂时将其命名为甲烷袋状菌属DTU006。其全长16S rRNA序列与黑海甲烷袋状菌JR1和棕榈甲烷袋状菌DSM 4273的相似性为97%。尽管16S基因序列相似度很高，但对所有蛋白质编码基因进行的平均核苷酸同一性计算（ANI）表明，两个最相似的物种，布尔根斯甲烷袋状菌MS2和甲烷袋状菌属MAB1，差异足够大，足以将甲烷袋状菌属DTU006定义为新的古菌物种。其基因组（2.15 Mbp）的估计完整性约为93%。使用京都基因与基因组百科全书（KEGG）对代谢途径进行分析证实，它是一种氢营养型产甲烷菌，因此建议给予其候选状态，将其命名为“候选嗜热氢营养甲烷袋状菌”。
