LaeA Controls Citric Acid Production through Regulation of the Citrate Exporter-Encoding Gene in Aspergillus luchuensis mut. .

The putative methyltransferase LaeA is a global regulator of metabolic and development processes in filamentous fungi. We characterized the homologous genes of the white koji fungus mut. () to determine their role in citric acid hyperproduction. The Δ strain exhibited a significant reduction in citric acid production. Cap analysis gene expression (CAGE) revealed that is required for the expression of a putative citrate exporter-encoding gene, which is critical for citric acid production. Deficient citric acid production by a Δ strain was rescued by the overexpression of to a level comparable with that of a -overexpressing Δ strain. In addition, chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) analysis indicated that LaeA regulates the expression of via methylation levels of the histones H3K4 and H3K9. These results indicate that LaeA is involved in citric acid production through epigenetic regulation of in has been traditionally used for production of the distilled spirit shochu in Japan. Citric acid produced by plays an important role in preventing microbial contamination during the shochu fermentation process. This study characterized homologous genes; using CAGE, complementation tests, and ChIP-qPCR, it was found that is required for citric acid production through the regulation of in The epigenetic regulation of citric acid production elucidated in this study will be useful for controlling the fermentation processes of shochu.