Methylocella silvestris is a facultative aerobic methanotrophic bacterium which uses not only methane, but also other alkanes such as ethane and propane, as carbon and energy sources. Its high metabolic versatility, together with the availability of tools for its genetic engineering, make it a very promising platform for metabolic engineering and industrial biotechnology using natural gas as substrate. The first Genome Scale Metabolic Model for M. silvestris is presented. The model has been used to predict the ability of M. silvestris to grow on 12 different substrates, the growth phenotype of two deletion mutants (ΔICL and ΔMS), and biomass yield on methane and ethanol. The model, together with phenotypic characterization of the deletion mutants, revealed that M. silvestris uses the glyoxylate shuttle for the assimilation of C1 and C2 substrates, which is unique in contrast to published reports of other methanotrophs. Two alternative pathways for propane metabolism have been identified and validated experimentally using enzyme activity tests and constructing a deletion mutant (Δ1641), which enabled the identification of acetol as one of the intermediates of propane assimilation via 2-propanol. The model was also used to integrate proteomic data and to identify key enzymes responsible for the adaptation of M. silvestris to different substrates. The model has been used to elucidate key metabolic features of M. silvestris, such as its use of the glyoxylate shuttle for the assimilation of one and two carbon compounds and the existence of two parallel metabolic pathways for propane assimilation. This model, together with the fact that tools for its genetic engineering already exist, paves the way for the use of M. silvestris as a platform for metabolic engineering and industrial exploitation of methanotrophs.

中文翻译：

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通用甲烷氧化亚甲基小球藻的基因组规模代谢模型。

Silvestris是一种兼性需氧甲烷氧化营养细菌，它不仅使用甲烷，还使用其他烷烃（例如乙烷和丙烷）作为碳和能源。它具有很高的代谢通用性，加上其基因工程工具的可用性，使其成为以天然气为底物的代谢工程和工业生物技术的非常有前途的平台。提出了第一个基因组规模代谢模型。该模型已被用于预测苜蓿分枝杆菌在12种不同底物上生长的能力，两个缺失突变体（ΔICL和ΔMS）的生长表型以及甲烷和乙醇的生物量产量。该模型与缺失突变体的表型特征一起显示，M。silvestris使用乙醛酸转运蛋白对C1和C2底物进行同化，与其他甲烷营养菌的公开报道相比，这是独特的。已使用酶活性测试和构建缺失突变体（Δ1641）鉴定并实验验证了丙烷代谢的两种替代途径，这使得能够将丙酮醇鉴定为通过2-丙醇进行丙烷同化的中间体之一。该模型还用于整合蛋白质组学数据，并鉴定负责使西莫氏梭菌适应不同底物的关键酶。该模型已被用于阐明芒草分枝杆菌的关键代谢特征，例如其使用乙醛酸酯穿梭物来同化一种和两种碳化合物，以及存在着两个平行的丙烷同化代谢途径。该模型以及其基因工程工具已经存在的事实，