Insights into the Underlying Mechanism of Ochratoxin A Production in CBS 513.88 Using Different Carbon Sources.

produces carcinogenic ochratoxin A (OTA), a serious food safety and human health concern. Here, the ability of CBS 513.88 to produce OTA using different carbon sources was investigated and the underlying regulatory mechanism was elucidated. The results indicated that 6% sucrose, glucose, and arabinose could trigger OTA biosynthesis and that 1586 differentially expressed genes (DEGs) overlapped compared to a non-inducing nutritional source, peptone. The genes that participated in OTA and its precursor phenylalanine biosynthesis, including , , , , and , were up-regulated, while the genes involved in oxidant detoxification, such as and , were down-regulated. Correspondingly, the activities of catalase and peroxidase were also decreased. Notably, the novel -like transcription factor An12g00840 (), which is vital in regulating OTA biosynthesis, was identified. Deletion of elevated the OTA yields by 47.65%, 54.60%, and 309.23% using sucrose, glucose, and arabinose as carbon sources, respectively. Additionally, deletion of increased the superoxide anion and HO contents, as well as the sensitivity to HO, using the three carbon sources. These results suggest that these three carbon sources repressed , leading to the up-regulation of the OTA biosynthetic genes and alteration of cellular redox homeostasis, ultimately triggering OTA biosynthesis in .