Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
Chan Zuckerberg Biohub, San Francisco, CA, USA.
Nat Rev Microbiol. 2018 Oct;16(10):629-645. doi: 10.1038/s41579-018-0076-2.
Candidate phyla radiation (CPR) bacteria and DPANN (an acronym of the names of the first included phyla) archaea are massive radiations of organisms that are widely distributed across Earth's environments, yet we know little about them. Initial indications are that they are consistently distinct from essentially all other bacteria and archaea owing to their small cell and genome sizes, limited metabolic capacities and often episymbiotic associations with other bacteria and archaea. In this Analysis, we investigate their biology and variations in metabolic capacities by analysis of approximately 1,000 genomes reconstructed from several metagenomics-based studies. We find that they are not monolithic in terms of metabolism but rather harbour a diversity of capacities consistent with a range of lifestyles and degrees of dependence on other organisms. Notably, however, certain CPR and DPANN groups seem to have exceedingly minimal biosynthetic capacities, whereas others could potentially be free living. Understanding of these microorganisms is important from the perspective of evolutionary studies and because their interactions with other organisms are likely to shape natural microbiome function.
候选门辐射（CPR）细菌和 DPANN（所包含的最初的门的名称的缩写）古菌是生物体的大规模辐射，它们广泛分布在地球的环境中，但我们对它们知之甚少。初步迹象表明，由于它们的细胞和基因组尺寸小、代谢能力有限，并且通常与其他细菌和古菌具有共生关系，因此它们与基本上所有其他细菌和古菌都明显不同。在本分析中，我们通过对基于几种宏基因组学研究重建的大约 1000 个基因组进行分析，研究了它们的生物学和代谢能力的变化。我们发现，它们在代谢方面并不是单一的，而是具有多样性的能力，这与一系列生活方式和对其他生物的依赖程度一致。然而，值得注意的是，某些 CPR 和 DPANN 群体的生物合成能力似乎极小，而其他群体则可能是自由生活的。从进化研究的角度来看，理解这些微生物是很重要的，因为它们与其他生物的相互作用可能会影响自然微生物组的功能。
