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Al-Shayeb, B.*; Sachdeva, R.*; Chen, L.-X.*; Ward, F.*; Munk, P.*; Devoto, A.*; Castelle, C. J.*; Olm, M. R.*; Bouma-Gregson, K.*; 天野 由記; et al.
Nature, 578(7795), p.425 - 431, 2020/02
被引用回数：223 パーセンタイル：99.47(Multidisciplinary Sciences)Phage typically have small genomes and depend on their bacterial hosts for replication. We generated metagenomic datasets from many diverse ecosystems and reconstructed hundreds of huge phage genomes, between 200 kbp and 716 kbp in length. Thirty four genomes were manually curated to completion, including the largest phage genomes yet reported. Expanded genetic repertoires include diverse and new CRISPR-Cas systems, tRNAs, tRNA synthetases, tRNA modification enzymes, initiation and elongation factors and ribosomal proteins. Phage CRISPR have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. Some phage repurpose bacterial systems for phage-defense to eliminate competing phage. We phylogenetically define seven major clades of huge phage from human and other animal microbiomes, oceans, lakes, sediments, soils and the built environment. We conclude that large gene inventories reflect a conserved biological strategy, observed across a broad bacterial host range and resulting in the distribution of huge phage across Earth's ecosystems.
Matheus Carnevali, P. B.*; Schulz, F.*; Castelle, C. J.*; Kantor, R. S.*; Shih, P.*; Sharon, I.*; Santini, J.*; Olm, M. R.*; 天野 由記; Thomas, B. C.*; et al.
Nature Communications (Internet), 10, p.463_1 - 463_15, 2019/01
被引用回数：35 パーセンタイル：86.27(Multidisciplinary Sciences)The metabolic platform in which microbial aerobic respiration evolved is tightly linked to the origins of Cyanobacteria (Oxyphotobacteria). Melainabacteria and Sericytochromatia, close phylogenetic neighbores to Oxyphotobacteria comprise both fermentative and aerobic representatives, or clades that are capablee of both. Here, we predict the metabolisms of Margulisbacteria from two distinct environments and Saganbacteria, and compare them to genomes of organisms from the related lineages. Melainabacteria BJ4A obtained from Mizunami site are potentially able to use O
and other terminal electron acceptors. The type C heme-copper oxygen reductase found in Melainabacteria BJ4A may be adapted to low O levels, as expected for microaerophilic or anoxic environments such as the subsurface. Notably, Melainabacteria BJ4A seems to have a branched electron transport chain, with one branch leading to a cytochrome d ubiquinol oxidoreductase and the other one leading to the type C heme-copper oxygen reductase. Both these enzymes have high affinity for O, thus are adapted to low O levels. These contemporary lineages have representatives with fermentative H-based metabolism, lineages capable of aerobic or anaerobic respiration, and lineages with both. Our findings support the idea that the ancestor of these lineages was an anaerobe in which fermentation and H metabolism were central metabolic features.
Magnani, N.*; Caciuffo, R.*; Colineau, E.*; Wastin, F.*; Amoretti, G.*; Carretta, S.*; Santini, P.*; Baraldi, A.*; Capelletti, R.*; Adroja, D. T.*; et al.
no journal, ,
近年Mn
, Fe
等の3d電子(遷移金属)系錯体が、新規な高密度記憶媒体や量子コンピューター素子としての応用の可能性を含めて広く注目されるようになっている。しかし、実用的には、希土類4f電子系の中心金属イオンを有する系が、より強い磁気異方性やより高い磁気ブロッキング温度を持った、より高性能の分子磁性体として期待されている。われわれは、この中でも最近特に注目を集めている4f希土類(Ln)系ダブルデッカー型フタロシアニン化合物の一つ、ツリウム(Tm)系のマクロ量(グラムオーダー)の試料合成に、初めて成功した。本試料を用い、ヨーロッパ超ウラン元素研究所らとの国際研究協力の下、光吸収,非弾性中性子散乱,比熱測定など多角的な手法で、本系の分子磁性にかかわる基礎物性の解明を開始した。本発表では、これらの成果について報告する。
