Effect of low frequency alternating magnetic field for erythritol production in Yarrowia lipolytica.

Numerous works have reported that magnetic fields serve as signals capable of influencing microbial metabolism. However, little is known about the effect of magnetic field on erythritol production by the model microorganism Yarrowia lipolytica (Y. lipolytica). Therefore, we investigated the effect of low-frequency alternating magnetic fields (LF-AMF) with different magnetic field intensities (0-1.5 mT) and different magnetic field treatment times (1-10 days) on the production of erythritol by Y. lipolytica -JZ204. The optimal treatment condition was 0.5 mT for 8 days. As a result, a maximal erythritol yield was achieved 63.74 g/L, the biomass was reached 37 g/L, and the specific erythritol yield per unit of biomass was 1.7227 g/g, which were 60.72%, 32.09%, and 24.85% higher than the control, respectively. We investigated the internal mechanism of magnetic fields impact by using transcriptomics and RT-qPCR technology. This study demonstrated the effectiveness of LF-AMF in enhancing erythritol production by Y. lipolytica JZ-204, providing insights for the application of magnetic field in assisting microbial fermentation and improving the synthesis of beneficial products.

Low frequency magnetic field assisted production of acidic protease by Aspergillus niger.

Acid protease is widely used in industries such as food processing and feed additives. In the study, low frequency magnetic field (LF-MF) as an aid enhances acid protease production by Aspergillus niger (A. niger). The study assessed mycelial biomass, the enzymic activity of the acidic protease and underlying mechanism. At low intensities, alternating magnetic field (AMF) is more effective than static magnetic fields (SMF). Under optimal magnetic field conditions, acid protease activity and biomass increased by 91.44% and 16.31%, as compared with the control, respectively. Maximum 19.87% increase in enzyme activity after magnetic field treatment of crude enzyme solution in control group. Transcriptomics analyses showed that low frequency alternating magnetic field (LF-AMF) treatment significantly upregulated genes related to hydrolases and cell growth. Our results showed that low-frequency magnetic fields can enhance the acid protease production ability of A. niger, and the effect of AMF is better at low intensities. The results revealed that the effect of magnetic field on the metabolic mechanism of A. niger and provided a reference for magnetic field-assisted fermentation of A. niger.