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Published on: August 31, 2015
Efficient Production of Natural Yellow Azaphilone Pigments from Monascus purpureus Regulated by
Lin-Qiang Xiong1, Yu-Zhen Li1, Su-Ping Liang1
1Guangdong Provincial Key Laboratory of Marine Biology, Department of Biology, College of Science, Shantou University, Shantou, Guangdong 515063, P. R. China.
Abstract:
Interaction with inert substances can profoundly affect the biosynthesis of metabolites in microorganisms. Here, we show that SiO2 microparticles cause changes in the cell morphology of Monascus purpureus. SiO2 also more than doubles the titer of yellow azaphilone pigments (YAzPs), reaching 788 U/mL. Transcriptomic and metabolomic analyses revealed that SiO2 microparticles modulated the expression of a large variety of genes and the production of key metabolites. In addition to upregulating the genes directly involved in YAzPs biosynthesis, the presence of SiO2 modulated the expression of key genes and the activities of key enzymes involved in calcium signaling and reactive oxygen species (ROS) response pathways. Together with SiO2-caused membrane damage, these changes are in accord with elevated levels of Ca2+ and ROS within the cells, as observed through specific reporters and validated by using inhibitors targeting these pathways. This research improves our understanding of the effects of inert substances on microbial metabolism.
