Insights into the Microbial Degradation of Rubber and Gutta-Percha by Analysis of the Complete Genome of Nocardia nova SH22a
Insights into the Microbial Degradation of Rubber and Gutta-Percha by Analysis of the Complete Genome of Nocardia nova SH22a
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DOI：
10.1128/aem.00473-14
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发表时间：
2014-07-01
影响因子：
4.4
通讯作者：
Steinbuechel, Alexander
中科院分区：
文献类型：
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作者：
Luo, Quan;Hiessl, Sebastian;Steinbuechel, Alexander
根据新诺卡氏菌SH22a对橡胶和杜仲胶(GP)的显著降解能力，测定了该菌株的全基因组序列。基因组全长8,348,532个碱基，G+C含量为67.77%，预测了7,583个蛋白质编码基因。72.45%的编码序列被赋予了功能。其中，检测到大量可能参与外源化合物和难降解化合物代谢的基因，以及参与合成聚酮和/或非核糖体肽类次生代谢物的基因。在电子分析和转座子诱变、基因定向缺失等实验研究的基础上，提出了橡胶和GP降解的途径，并揭示了两者之间的关系。除其他外，涉及的基因包括参与细胞被膜合成的基因(长链脂肪酸-AMP连接酶和阿拉伯呋喃糖基转移酶)、β-氧化(α-甲基酰基辅酶A[α-甲基酰基辅酶A]外消旋酶)、丙酸分解代谢(酰基辅酶A羧基酶)、糖异生(磷酸烯醇式丙酮酸羧酸激酶)和跨膜底物摄取(MCE[哺乳动物细胞进入]转运体)。这项研究不仅加深了我们对橡胶和GP微生物降解机理的认识，而且扩大了我们对诺卡氏菌属代谢多样性的认识。
The complete genome sequence of Nocardia nova SH22a was determined in light of the remarkable ability of rubber and guttapercha (GP) degradation of this strain. The genome consists of a circular chromosome of 8,348,532 bp with a G+C content of 67.77% and 7,583 predicted protein-encoding genes. Functions were assigned to 72.45% of the coding sequences. Among them, a large number of genes probably involved in the metabolism of xenobiotics and hardly degradable compounds, as well as genes that participate in the synthesis of polyketide-and/or nonribosomal peptide-type secondary metabolites, were detected. Based on in silico analyses and experimental studies, such as transposon mutagenesis and directed gene deletion studies, the pathways of rubber and GP degradation were proposed and the relationship between both pathways was unraveled. The genes involved include, inter alia, genes participating in cell envelope synthesis (long-chain-fatty-acid-AMP ligase and arabinofuranosyltransferase), beta-oxidation (alpha-methylacyl-coenzyme A [alpha-methylacyl-CoA] racemase), propionate catabolism (acyl-CoA carboxylase), gluconeogenesis (phosphoenolpyruvate carboxykinase), and transmembrane substrate uptake (Mce [mammalian cell entry] transporter). This study not only improves our insights into the mechanism of microbial degradation of rubber and GP but also expands our knowledge of the genus Nocardia regarding metabolic diversity.