The biochemically versatile fungus Aspergillus niger produces a wide array of acids and enzymes. This metabolic diversity and its ability to use a large amount of different carbon sources make Aspergillus niger a valuable cell factory for applications in many different industrial processes.
|Exposure duration||continuous for 4 h, 6 h or 8 h|
|Chamber||six sets of 3 cylindrical coils wrapped with magnetic shielding material, fastened to the rocking bed and rotated at 200 rpm; each coil 600 mm long with an inner diameter of 100 mm; outer diameters of the coils: 114 mm, 120 mm, 126 mm, 132 mm, 138 mm and 144 mm; number of threads of wire with 2 mm diameter: 1200, 1800, 2400, 3000, 3600 and 4200; cultures placed in 80 mm heigh glass shake flasks with a diamter of 60 mm on a non-conductive stand in the middle of each coil; temperature kept constant at 30° C|
Both yield of citric acid and enzyme activity of cellulase increased with increasing exposure time and/or magnetic flux density, but the metabolism of citric acid was more sensitive to the magnetic field than that of cellulase. From the measurement of the metabolism dynamics the authors concluded that the increase in the citric acid production and cellulase enzyme activity started immediately after the magnetic field was switched on.