Light, magnetic field, and methylation affected the growth and secondary metabolism of fungi. The regulation effect of the three factors on the growth and Monascus pigments (MPs) synthesis of Monascus purpureus was investigated in this study. 5-azacytidine (5-AzaC), DNA methylation inhibitor, was used to treat M. purpureus (wild-type, WT). Twenty micromolar 5-AzaC significantly promoted the growth, development, and MPs yield. Moreover, 250 lux red light and red light coupled magnetic field (RLCMF) significantly promoted the biomass. For WT, red light, and RLCMF significantly promoted MPs yield. But compared with red light treatment, only 0.2 mT RLCMF promoted the alcohol-soluble MPs yield. For histone H3K4 methyltransferase complex subunit Ash2 gene knockout strain (Δ Ash2 ), only 0.2 mT RLCMF significantly promoted water-soluble MPs yield. Yet red light, 1.0 and 0.2 mT RLCMF significantly promoted alcohol-soluble MPs yield. This indicated that methylation affected the MPs biosynthesis. Red light and weaker MF had a synergistic effect on the growth and MPs synthesis of Δ Ash2 . This result was further confirmed by the expression of related genes. Therefore, histone H3K4 methyltransferase was involved in the regulation of the growth, development, and MPs synthesis of M. purpureus by the RLCMF.
Both chemical catalysis and microbial fermentation are essential ways to produce small molecules related to our everyday lives. The apparent mismatch between the approaches used in synthetic organic chemistry and the culture conditions required to support living micro-organisms remains one of the largest challenges in combining chemical catalysis with microbial fermentation in a one-pot procedure. In the present work, microbial fermentation of red Monascus pigments, which involves biosynthesis of orange Monascus pigments and non-enzymatic chemical conversion of hydrophobic orange Monascus pigments into red ones, was set up as a model. Inverse phase transfer catalysis (IPTC) consisting of a water–tetradecane two-phase system with hydroxypropyl-β-cyclodextrin as an inverse phase transfer catalyst was exploited to accelerate the chemical modification of hydrophobic orange Monascus pigments. At the same time, Monascus aurantiacus exhibited excellent biocompatibility in this system. Thus, microbial fermentation and further chemical modification of orange Monascus pigments had been merged successfully in one-pot by IPTC, where the shift of the microbial metabolic flux to orange Monascus pigments (almost undetectable yellow Monascus pigments) and efficient production of red Monascus pigments (corresponding to nearly 2 g l−1) were achieved. This is the first report about exploitation of IPTC as a biocompatible medium for merging of a chemical reaction with microbial metabolism.
危险品化学品经营许可证（带存储）