Production of mannosylerythritol lipids: biosynthesis, multi-omics approaches, and commercial exploitation

The production of mannosylerythritol lipids (MELs) has been reported on different smut fungi. These biomolecules possess four typical conformations to which key commercially interesting properties have been attributed. In vivo, MEL production could only be explained by the chain-shortening pathway, a new route, unlike the main three fatty acid synthesis pathways described. The production of MELs requires nitrogen starvation and a carbon source, usually a fatty acid, the principals. The first MEL biosynthetic gene cluster was elucidated in U. maydis by the combination of different methodologies, which resulted in a reference genome, on which five genes comprising the MEL cluster were annotated. Subsequently, the evolution of DNA sequencing technologies advanced genome and transcriptome assembly, allowing the annotation of more MEL producers' genomes. These, in combination with different experimental techniques, coupled to bioinformatic methods offer a plethora of genomic resources for further manipulation and commercial exploitation. In this review, we present the main findings, which unraveled MEL production and multi-omics studies, leading to molecular tools for further genomic manipulation and exploitation in smut fungi.