Abstract: Lotus root is apt to be spoiled by Fusarium oxysporum due to its rich nutrition. In order to explore a method to inhibit the spoilage microbe, the effect of air discharge treatment on substance and energy metabolism in Fusarium oxysporum was studied, and we further investigated the cell membrane damage caused by air discharge at the cellular level. Three treatments were set up by using ozone at 6.87 mg/m3 or/and negative ions at 5 × 106 ions/cm3, respectively, and untreated Fusarium oxysporum was regarded as the control group. Results showed that after air discharge treatment, the metabolic balance of Fusarium oxysporum mycelium was destroyed, and consequently sugar and protein accumulated. Respiratory intensity and ATP synthesis decreased significantly (P < 0.05). Moreover, the cell membrane permeability increased, the integrity was destroyed, the fluidity significantly decreased (P < 0.05), and the membrane potential increased significantly (P < 0.05). Compared with the single treatments, the combined treatment was more effective in destroying cell membrane structure. In conclusion, air discharge exerted bacteriostatic effect by changing the cell membrane permeability and integrity of Fusarium oxysporum, and inhibiting catabolism, consequently decreasing ATP supply and finally affecting cell viability.

Key words: air discharge, Fusarium oxysporum, substance metabolism, energy metabolism, cell membrane