Monascus purpureus is used to yield edible pigments accompanied by mycotoxin-citrinin. A low-frequency (<300 Hz) magnetic field (LF-MF) affects microbial metabolism. The link of LF-MF with secondary metabolites and intracellular and extracellular Na+ levels in M. purpureus was determined. The fermentation broth was exposed to LF-MF during the first 2 days of fermentation and continuously cultured at 30°C and 200 rpm until the 8th day of fermentation. Results showed that LF-MF treatments didn't affect the growth of M. purpureus in liquid-state fermentation. Compared with the control, citrinin production showed a decrease of 45.0%, while yellow, red, and orange pigment production showed an increase of 72.9, 73.9, and 40.1%, respectively, with LF-MF treatment of 1.6 mT. This was in agreement with downregulation of pksCT and ctnA, and upregulation of pksPT, pigR, veA, and laeA at the transcriptional level. Moreover, 1.6 mT LF-MF exposure caused the transfer of Na+ from extracellular to intracellular, which was validated through the upregulation of transmembrane sensor synthesis genes and the changes in the relative expression levels of the P-type ATPase and protein phosphatase genes. This study established that LF-MF could inhibit citrinin and stimulate pigment production and change intracellular and extracellular Na+ concentrations. Bioelectromagnetics. 2020;41:289-297 © 2020 Bioelectromagnetics Society.

中文翻译：

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适当强度的低频磁场改变了细胞内和细胞外红曲霉的次生代谢产物的产生和Na +的浓度。

紫红曲霉用于产生可食用色素，并伴有霉菌毒素-citrinin。低频（<300 Hz）磁场（LF-MF）影响微生物的代谢。确定了LF-MF与次级代谢产物以及紫癜支原体中细胞内和细胞外Na +水平的联系。在发酵的前两天，将发酵液暴露于LF-MF中，并在30°C和200 rpm下连续培养直至发酵的第八天。结果表明，LF-MF处理不影响紫杉分枝杆菌在液态发酵中的生长。与对照组相比，用1.6 mT的LF-MF处理，桔霉素产量减少45.0％，而黄色，红色和橙色颜料产量分别增加72.9％，73.9和40.1％。这与pksCT和ctnA的下调一致，并在转录水平上调pksPT，pigR，veA和laeA。此外，1.6 mT LF-MF暴露引起Na +从细胞外转移到细胞内，这通过跨膜传感器合成基因的上调以及P型ATPase和蛋白磷酸酶基因的相对表达水平的变化得到证实。这项研究建立了LF-MF可以抑制橘皮苷和刺激色素生成并改变细胞内和细胞外Na +的浓度。生物电磁学。2020; 41：289-297©2020生物电磁学会。通过跨膜传感器合成基因的上调以及P型ATPase和蛋白磷酸酶基因相对表达水平的变化，证实了这一点。这项研究建立了LF-MF可以抑制橘皮苷和刺激色素生成并改变细胞内和细胞外Na +的浓度。生物电磁学。2020; 41：289-297©2020生物电磁学会。通过跨膜传感器合成基因的上调以及P型ATPase和蛋白磷酸酶基因相对表达水平的变化，证实了这一点。这项研究建立了LF-MF可以抑制橘皮苷和刺激色素生成并改变细胞内和细胞外Na +的浓度。生物电磁学。2020; 41：289-297©2020生物电磁学会。