Transcriptional Interplay Between and Species Co-Existing in the Skin Environment

and are the most dominant genera in human skin microbiome. To explore the inter-kingdom interactions between the two genera, we examined the transcriptional changes in and species induced upon co-culturing. RNA-seq analyses revealed that genes encoding ribosomal proteins were upregulated, while those encoding aspartyl proteases were downregulated in after co-culturing with species. We identified MRET_3770 as a major secretory aspartyl protease coding gene in through pepstatin-A affinity chromatography followed by mass spectrometry and found that the expression of MRET_3770 was significantly repressed upon co-culturing with species or by incubation in media with reduced pH. Moreover, biofilm formation by was inhibited in the spent medium of , suggesting that biomolecules secreted by such as secretory aspartyl proteases may degrade the biofilm structure. We also examined the transcriptional changes in co-cultured with and found co-cultured showed increased expression of genes encoding ribosomal proteins and downregulation of those involved in riboflavin metabolism. These transcriptome data of co-cultured fungal and bacterial species demonstrate a dynamic interplay between the two co-existing genera.