Isoprene is the most abundantly produced biogenic volatile organic compound (BVOC) on Earth, with annual global emissions almost equal to those of methane. Despite its importance in atmospheric chemistry and climate, little is known about the biological degradation of isoprene in the environment. The largest source of isoprene is terrestrial plants, and oil palms, the cultivation of which is expanding rapidly, are among the highest isoprene-producing trees. DNA stable isotope probing (DNA-SIP) to study the microbial isoprene-degrading community associated with oil palm trees revealed novel genera of isoprene-utilising bacteria including Novosphingobium, Pelomonas, Rhodoblastus, Sphingomonas and Zoogloea in both oil palm soils and on leaves. Amplicon sequencing of isoA genes, which encode the α-subunit of the isoprene monooxygenase (IsoMO), a key enzyme in isoprene metabolism, confirmed that oil palm trees harbour a novel diversity of isoA sequences. In addition, metagenome-assembled genomes (MAGs) were reconstructed from oil palm soil and leaf metagenomes and putative isoprene degradation genes were identified. Analysis of unenriched metagenomes showed that isoA-containing bacteria are more abundant in soils than in the oil palm phyllosphere. This study greatly expands the known diversity of bacteria that can metabolise isoprene and contributes to a better understanding of the biological degradation of this important but neglected climate-active gas.

中文翻译：

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来自高异戊二烯排放环境的叶际和土壤群落中异戊二烯降解细菌的多样性：马来西亚油棕种植园。


异戊二烯是地球上产生最丰富的生物挥发性有机化合物（BVOC），全球每年的排放量几乎与甲烷相当。尽管异戊二烯在大气化学和气候中很重要，但人们对环境中异戊二烯的生物降解知之甚少。异戊二烯的最大来源是陆地植物，而油棕的种植规模正在迅速扩大，是异戊二烯产量最高的树木之一。 DNA稳定同位素探测（DNA-SIP）研究与油棕树相关的微生物异戊二烯降解群落，揭示了油棕土壤和叶子上新的异戊二烯利用细菌属，包括Novosphingobium、Pelomonas、Rhodoblastus、Sphingomonas和Zoogloea。 isoA 基因编码异戊二烯单加氧酶 (IsoMO)（异戊二烯代谢中的关键酶）的 α 亚基，对 isoA 基因的扩增子测序证实，油棕榈树具有新颖的 isoA 序列多样性。此外，从油棕土壤和叶子宏基因组中重建了宏基因组组装基因组（MAG），并鉴定了假定的异戊二烯降解基因。对未富集宏基因组的分析表明，土壤中含有 isoA 的细菌比油棕叶际中的细菌更为丰富。这项研究极大地扩展了已知的可代谢异戊二烯的细菌多样性，并有助于更好地了解这种重要但被忽视的气候活跃气体的生物降解。