The GATA type transcriptional factors regulate pullulan biosynthesis in Aureobasidium melanogenum P16

• Published in: International journal of biological macromolecules 2021-12, Vol.192, p.161-168
• Main Authors: Kang, Xin-Xin, Wang, Qin-Qing, Chi, Zhe, Liu, Guang-Lei, Hu, Zhong, Chi, Zhen-Ming
• Format: Article
• Language: English
• Subjects: AreA; AreB; Aureobasidium - genetics; Aureobasidium - metabolism; Aureobasidium melanogenum; Cloning, Molecular; GATA Transcription Factors - metabolism; Gene Deletion; Gene Expression; Gene Expression Regulation, Fungal; Glucans - biosynthesis; Glucans - genetics; Nitrogen catabolite repression; Pullulan biosynthesis; Recombinant Fusion Proteins
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.09.149

Aureobasidium melanogenum P16, the high pullulan producer, had only one GATA type transcriptional activator AreA and one GATA type transcriptional repressor AreB. It was found that 2.4 g/L of (NH4)2SO4 had obvious nitrogen repression on pullulan biosynthesis by A. melanogenum P16. Removal of the AreB gene could make the disruptant DA6 produce 34.8 g/L pullulan while the P16 strain only produced 28.8 g/L pullulan at the efficient nitrogen condition. Further both removal of the native AreA gene and overexpression of the mutated AreAS628-S678 gene with non-phosphorylatable residues could render the transformant DEA12 to produce 39.8 g/L pullulan. The transcriptional levels of most of the genes related to pullulan biosynthesis in the transformant DEA12 were greatly enhanced. The mutated AreAS628-S678 was localized in the nuclei of the transformant DEA12 while the native AreA was distributed in the cytoplasm in A. melanogenum P16. This meant that nitrogen repression on pullulan biosynthesis in the transformant DEA12 was indeed significantly relieved. This was the first time to report that the GATA type transcriptional factors of nitrogen catabolite repression system could regulate pullulan biosynthesis in Aureobasidium spp. •The GATA type transcriptional activator AreA and the transcriptional repressor AreB were removed.•The mutated AreA gene with nonphosphorylatable residues was overexpressed.•The obtained derepressed mutant could produce 39.8 g/L pullulan.•The mutated AreA was only localized in the nuclei of the derepressed mutant.