Mycoplasma pneumoniae is a slow-growing, human pathogen that causes atypical pneumonia. Because it lacks a cell wall, many antibiotics are ineffective. Due to its reduced genome and dearth of many biosynthetic pathways, this fastidious bacterium depends on rich, undefined medium for growth, which makes large-scale cultivation challenging and expensive. To understand factors limiting growth, we developed a genome-scale, constraint-based model of M. pneumoniae called iEG158_mpn to describe the metabolic potential of this bacterium. We have put special emphasis on cell membrane formation to identify key lipid components to maximize bacterial growth. We have used this knowledge to predict essential components validated with in vitro serum-free media able to sustain growth. Our findings also show that glycolysis and lipid metabolism are much less efficient under hypoxia; these findings suggest that factors other than metabolism and membrane formation alone affect the growth of M. pneumoniae. Altogether, our modelling approach allowed us to optimize medium composition, enabled growth in defined media and streamlined operational requirements, thereby providing the basis for stable, reproducible and less expensive production.

肺炎支原体是一种生长缓慢的人类病原体，可引起非典型肺炎。因为它没有细胞壁，所以许多抗生素无效。由于其基因组减少和许多生物合成途径的缺乏，这种挑剔的细菌依赖于丰富的、不确定的培养基进行生长，这使得大规模培养具有挑战性且成本高昂。为了了解限制生长的因素，我们开发了一个基因组规模的、基于约束的肺炎支原体模型称为 iEG158_mpn 来描述这种细菌的代谢潜力。我们特别强调细胞膜的形成，以确定关键的脂质成分，以最大限度地提高细菌的生长。我们已经利用这些知识来预测用能够维持生长的体外无血清培养基验证的基本成分。我们的研究结果还表明，在缺氧条件下糖酵解和脂质代谢的效率要低得多。这些发现表明，除了代谢和膜形成之外，其他因素也会影响肺炎支原体的生长。总而言之，我们的建模方法使我们能够优化培养基组成，实现特定培养基的增长并简化操作要求，从而为稳定、可重复且成本更低的生产奠定基础。