## 3 Results
### Plasma Jet Increases \(\alpha\)-Amylase Secretion in A. oryzae  
The secretion of \(\alpha\)-amylase into PDB media by _A. oryzae_ was analyzed by measuring the extracellular levels of total protein secretion and \(\alpha\)-amylase activity post plasma treatment of the fungal spores. Generally, an increase in total protein concentration in the PDB media of up to 0.029 mg/mL was observed in all samples during incubation (144 h of incubation in the 15 min plasma treatment group), regardless of plasma treatment (Figure 3a). However, no significant differences in total protein concentrations (mg/mL) were observed between the control (0 min) and the plasma jet-treated samples at each incubation time (24-168 h) (Figure 3a). Figure 2: Spore germination and growth of _A. oryzae_ post treatment with a plasma jet for 5, 10, 15, and 20 min, or without treatment (0 min = control). **(a)** Log-scale number of germinated spores in a 1 mL suspension with or without treatment with a plasma jet. **(b)** The relative germination percentage (%) of plasma-treated samples compared with that of the control (0 min, 100%). **(c)** The dry weight of the fungal mycelia grown for 48 h in a 50 mL culture. Each value is indicated as the mean and standard deviation of 6–9 replicate measurements. **\(p<0.01\). An increase in \(\alpha\)-amylase activity per mL of PDB media was observed in all samples following incubation (Figure 3b). At all incubation times except 168 h, the \(\alpha\)-amylase activity was significantly higher (\(p<0.05\) and 0.01) in the media of the plasma-treated samples than in that of the control (Figure 3b). A significant increase was more frequently observed under the conditions of 10 min and 15 min of plasma treatment and shorter incubation times (24-96 h) (Figure 3b). Treatment with the plasma jet for 20 min did  
Figure 3: Total protein secretion and \(\alpha\)-amylase activity of _A. oryzae_ during incubation post treatment with a plasma jet for 5, 10, 15, and 20 min, or without treatment (0 min = control). (**a**) The concentration of total protein in the potato dextrose broth (PDB) media (mg/mL) post incubation for the indicated time periods. (**b**) The \(\alpha\)-amylase activity (Unit/mL) detected in the PDB media post incubation for the indicated time periods. (**c**) The specific \(\alpha\)-amylase activity (Unit/mg of total protein) estimated in the PDB media post incubation for the indicated time periods. All values were calibrated with the background (0 h incubation) values. Each value is indicated as the mean and standard deviation of 6 replicate measurements. **_p_ < 0.01 and *_p_ < 0.05.  
not seem to have a significant effect on \(\alpha\)-amylase activity in the media over the entire incubation period (Figure 3b). The specific activity of \(\alpha\)-amylase (enzyme activity expressed per milligram of total protein) in the PDB media was significantly greater (\(p<0.05\) and \(0.01\)) in the plasma-treated samples than in the control over all incubation periods (Figure 3c). Plasma treatment for 20 min showed a relatively lower increase in specific activity, compared with other treatment times (Figure 3c). The highest levels of fold increase in specific activity were observed in the conditions of 10 min and 15 min of plasma treatment after incubation for 72 h, which were approximately 2.38-fold and 2.93-fold, respectively (Figure 3c). Level of \(\text{NO}_{\text{X}}\) Species and Oxidation Reduction Potential in PDB Increases after Plasma Treatment  
Previously, we found that the plasma-induced elevation in \(\alpha\)-amylase secretion by _A. oryzae_ was closely associated with the \(\text{NO}_{\text{X}}\) species, particularly \(\text{NO}_{2}\)\({}^{-}\) and \(\text{NO}_{3}\)\({}^{-}\) generated in the media post plasma treatment [18]. Thus, we investigated the levels of \(\text{NO}_{\text{X}}\), \(\text{NO}_{2}\)\({}^{-}\), \(\text{NO}_{3}\)\({}^{-}\), and \(\text{H}_{2}\text{O}_{2}\) in the PDB media post plasma treatment.