Identification of novel anthocyanins synthesis pathway from fungus, Aspergillus sydowii H-1

Background Anthocyanins are common substance in people's production and life. Usually it was used as a natural dye, more and more studies have shown that anthocyanins have potential preventive and / or therapeutic effects on human health, such as improving cardiovascular function and treating obesity. However, anthocyanins are generally thought to occur only in natural plants. The difficulty of mass production limits the application of anthocyanins in industry. Production of anthocyanins from microbial fermentation is not restricted by time, space and environmental conditions as compared with plants, which makes it more anxious to obtain anthocyanins from microorganisms. Here, we firstly reported a fungus, Aspergillus sydowii H-1which can produce anthocyanins under the specific fermentation, and analyzed its metabolome and transcriptome. Results All of the 31 gene loci related to anthocyanins synthesis pathway were identified in A. sydowii H-1, and almost all of those genes display high correlation with the data from metabolome. Among them, chalcone synthase gene (CHS) and cinnamate-4-hydroxylase gene (C4H) were only found using denovo assembly without reference, and interestingly, the best hits of these two genes all belong to plant species. Therefore, the plant-derived genes, CHS and C4H, may be one of the reasons why A. sydowii H-1 can produce anthocyanins. We also identified 530 lncRNAs in our datasets, and among them, three lncRNAs targeted to the genes related to anthocyanins biosynthesis via cis-regulation, which likewise provide clues for the underlying mechanism of anthocyanins’ production in the fungi. Conclusions In this study, we discovered a fungus, Aspergillus sydowii H-1, which can produce anthocyanins under the specific fermentation condition. It’s the first report that anthocyanins can be produced in non-plant species.