PDF(Pubmed)
Abstract：
Mucor circinelloides serves as a model organism to investigate the lipid metabolism in oleaginous microorganisms. It is considered as an important producer of γ-linolenic acid (GLA) that has vital medicinal benefits. In this study, we used WJ11, a high lipid-producing strain of M. circinelloides (36% w/w lipid, cell dry weight, CDW), to examine the role in lipid accumulation of two mitochondrial malic enzyme (ME) genes malC and malD. The homologous overexpression of both malC and malD genes enhanced the total lipid content of WJ11 by 41.16 and 32.34%, respectively. In parallel, the total content of GLA was enhanced by 16.73 and 46.76% in malC and malD overexpressing strains, respectively, because of the elevation of total lipid content. The fact that GLA content was enhanced more in the strain with lower lipid content increase and vice versa, indicated that engineering of mitochondrial MEs altered the fatty acid profile. Our results reveal that mitochondrial ME plays an important role in lipid metabolism and suggest that future approaches may involve simultaneous overexpression of distinct ME genes to boost lipid accumulation even further.
摘要：
毛霉是研究含油微生物中脂质代谢的模型生物。它被认为是具有重要药用益处的γ-亚麻酸（GLA）的重要生产者。在这项研究中,我们使用了WJ11，这是一种高脂质生产菌株，(36%w/w脂质，细胞干重，CDW)，检查两个线粒体苹果酸酶（ME）基因malC和malD在脂质积累中的作用。malC和malD基因的同源过表达使WJ11的总脂质含量分别提高了41.16和32.34％，分别。并行,在malC和malD过表达菌株中，GLA的总含量分别提高了16.73和46.76％，分别,因为总脂质含量的升高。事实上，GLA含量在较低脂含量增加的菌株中增加更多，反之亦然，表明MEs线粒体工程改变了脂肪酸谱。我们的结果表明，线粒体ME在脂质代谢中起着重要作用，并表明未来的方法可能涉及不同ME基因的同时过表达，以进一步促进脂质积累。
