Genome-scale analysis of the metabolic networks of oleaginous Zygomycete fungi

• Metabolic annotation of Mortierella alpina and Mucor circinelloides genomes
• Construction of genome-scale metabolic networks of the oleaginous fungi
• Identification of consensus metabolic routes of the oleaginous fungi
• Unique metabolic features in fungi (NADPH and sterol metabolisms) identified
• The metabolic inter-relationship frameworks of the oleaginous fungi generated

Microbial lipids are becoming an attractive option for the industrial production of foods and oleochemicals. To investigate the lipid physiology of the oleaginous microorganisms, at the system level, genome-scale metabolic networks of Mortierella alpina and Mucor circinelloides were constructed using bioinformatics and systems biology. As scaffolds for integrated data analysis focusing on lipid production, consensus metabolic routes governing fatty acid synthesis, and lipid storage and mobilisation were identified by comparative analysis of developed metabolic networks. Unique metabolic features were identified in individual fungi, particularly in NADPH metabolism and sterol biosynthesis, which might be related to differences in fungal lipid phenotypes. The frameworks detailing the metabolic relationship between M. alpina and M. circinelloides generated in this study is useful for further elucidation of the microbial oleaginicity, which might lead to the production improvement of microbial oils as alternative feedstocks for oleochemical industry.