Luo Zhen-Hao, Li Qi, Lai Yan, Chen Hao, Liao Bin, Huang Li-Nan
School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
Front Microbiol. 2020 Dec 21;11:612257. doi: 10.3389/fmicb.2020.612257. eCollection 2020.
Recent genome-resolved metagenomic analyses of microbial communities from diverse environments have led to the discovery of many novel lineages that significantly expand the phylogenetic breadth of Archaea. Here, we report the genomic characterization of a new archaeal family based on five metagenome-assembled genomes retrieved from acid mine drainage sediments. Phylogenomic analyses placed these uncultivated archaea at the root of the candidate phylum Parvarchaeota, which expand this lesser-known phylum into two family levels. Genes involved in environmental adaptation and carbohydrate and protein utilization were identified in the ultra-small genomes (estimated size 0.53-0.76 Mb), indicating a survival strategy in this harsh environment (low pH and high heavy metal content). The detection of genes with homology to sulfocyanin suggested a potential involvement in iron cycling. Nevertheless, the absence of the ability to synthesize amino acids and nucleotides implies that these archaea may acquire these biomolecules from the environment or other community members. Applying evolutionary history analysis to Parvarchaeota suggested that members of the two families could broaden their niches by acquiring the potentials of utilizing different substrates. This study expands our knowledge of the diversity, metabolic capacity, and evolutionary history of the Parvarchaeota.
最近，对来自不同环境的微生物群落进行的基因组解析宏基因组分析，发现了许多新的谱系，这些谱系显著扩展了古菌的系统发育广度。在此，我们基于从酸性矿山排水沉积物中检索到的5个宏基因组组装基因组，报告了一个新的古菌家族的基因组特征。系统发育基因组分析将这些未培养的古菌置于候选门“微小古菌门”的根部，这将这个鲜为人知的门扩展到了两个家族水平。在超小基因组（估计大小为0.53 - 0.76 Mb）中鉴定出了参与环境适应以及碳水化合物和蛋白质利用的基因，这表明了它们在这种恶劣环境（低pH值和高重金属含量）中的生存策略。与硫氰蛋白具有同源性的基因的检测表明其可能参与铁循环。然而，缺乏合成氨基酸和核苷酸的能力意味着这些古菌可能从环境或其他群落成员那里获取这些生物分子。对微小古菌门进行进化历史分析表明，这两个家族的成员可以通过获得利用不同底物的潜力来拓宽其生态位。这项研究扩展了我们对微小古菌门的多样性、代谢能力和进化历史的认识。
