Influence of Cmr1 in the Regulation of Antioxidant Function Melanin Biosynthesis in Aureobasidium pullulans

Wan Wang; Kai Zhang; Congyu Lin; Shanshan Zhao; Jiaqi Guan; Wei Zhou; Xin Ru; Hua Cong; Qian Yang

doi:10.3390/foods12112135

Influence of Cmr1 in the Regulation of Antioxidant Function Melanin Biosynthesis in Aureobasidium pullulans

Foods. 2023 May 25;12(11):2135. doi: 10.3390/foods12112135.

Authors

Wan Wang¹, Kai Zhang¹, Congyu Lin², Shanshan Zhao³, Jiaqi Guan¹, Wei Zhou¹, Xin Ru¹, Hua Cong¹, Qian Yang^{1

4}

Affiliations

¹ School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China.
² National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
³ Ocean College, Zhejiang University, Zhoushan 316000, China.
⁴ State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China.

Abstract

We have successfully identified the transcription factor Cmr1 from the fungus Aureobasidium pullulans Hit-lcy3T, which regulates melanin biosynthesis genes. Bioinformatics analysis revealed that the Cmr1 gene encodes a protein of 945 amino acids, containing two Cys₂His₂ zinc finger domains and a Zn(II)₂Cys₆ binuclear cluster domain located at the N-terminus of Cmr1. To investigate the function of the Cmr1 gene, we performed gene knockout and overexpression experiments. Our results showed that Cmr1 is a key regulator of melanin synthesis in Hit-lcy3^T, and its absence caused developmental defects. Conversely, overexpression of Cmr1 significantly increased the number of chlamydospores in Hit-lcy3^T and improved melanin production. RT-qPCR analysis further revealed that overexpression of Cmr1 enhanced the expression of several genes involved in melanin biosynthesis, including Cmr1, PKS, SCD1, and THR1. Melanin extracted from the Hit-lcy3^T was characterized using UV and IR spectroscopy. Furthermore, we assessed the antioxidant properties of Hit-lcy3^T melanin and found that it possesses strong scavenging activity against DPPH·, ABTS·, and OH·, but weaker activity against O₂^-·. These findings suggest that Hit-lcy3^T melanin holds promise for future development as a functional food additive.

Keywords: Aureobasidium pullulans; Cmr1; antioxidant activity; melanin.

Grants and funding

This research received no external funding.