## 3 Results
### Two-Stage Fermentation of Bread Hydrolysate  
Fermentations with _N. intermedia_ were repeated and analyzed for efficiency every 24 h. The utilization of dextrin present in the medium started from the beginning of the cultivation, resulting in an almost linear slope of its concentration profile (Figure 1a). Within the first 24 h of fermentation, the concentration of all other analyzed sugars increased by approx. 5 g/L. After that, malotriose was depleted from the medium, while the concentration of glucose and maltose continued to increase, reaching similar values (approx. 27 g/L) after 48 h. Throughout the final day of the fermentation process, maltose was utilized by the fungus to a final concentration of 3.3 \(\pm\) 1.6 g/L. At the same time, glucose concentration continued to increase to a final level of 29.6 \(\pm\) 2.6 g/L, resulting in a nearly six-fold increase in comparison to its initial content. In general, the final concentrations of carbohydrates were similar to those obtained for _N. intermedia_ in the screening experiment. It was found that the production of ethanol by the fungus was slow during the first day of fermentation (Figure 1b). Its concentration reached 3.4 \(\pm\) 0.2 g/L after 24 h with volumetric productivity of 0.14 g/L \(\times\) h. The corresponding values obtained after 48 and 72 h reached 17.6 \(\pm\) 1.0 g/L, 0.59 g/L \(\times\) h and 32.2 \(\pm\) 2.1 g/L and 0.60 g/L \(\times\) h, respectively. It was observed that the highest biomass content (26.5 \(\pm\) 2.2 g/L) was achieved after the first day of fermentation, after which it gradually decreased to a final level of 19.2 \(\pm\) 0.4 g/L. This observation proves that the fungus was able to hydrolyze the undissolved particles present in the medium. The protein content in the resulting biomass was similar to that determined in the screening experiment, i.e., 0.45 \(\pm\) 0.01 g/g (data not shown). \begin{table}
\begin{tabular}{c c c c c} \hline
**Concentration (g/L)** & _N. intermedia_ & _A. oryzae_ & _R. oryzae_ & _M. indicus_ \\ \hline Dextrin & 13.88 \(\pm\) 1.92 & 10.12 \(\pm\) 0.84 & 42.65 \(\pm\) 0.13 & 17.54 \(\pm\) 0.22 \\ Maltoriose & 5.12 \(\pm\) 0.11 & 2.66 \(\pm\) 0.17 & 4.40 \(\pm\) 0.58 & 6.00 \(\pm\) 0.10 \\ Maltose & 2.76 \(\pm\) 0.64 & 3.48 \(\pm\) 0.09 & 33.58 \(\pm\) 0.17 & n.d. \\ Glucose & 28.67 \(\pm\) 2.38 & 24.22 \(\pm\) 1.85 & 1.48 \(\pm\) 0.08 & 17.13 \(\pm\) 2.27 \\ Lactic acid & n.d. & n.d. & 1.93 \(\pm\) 0.16 & n.d. \\ Glycerol & 1.58 \(\pm\) 0.01 & 1.22 \(\pm\) 0.03 & 1.68 \(\pm\) 0.05 & 2.69 \(\pm\) 0.01 \\ Ethanol & 32.90 \(\pm\) 0.74 & 18.55 \(\pm\) 0.26 & 21.27 \(\pm\) 0.65 & 29.42 \(\pm\) 0.42 \\ Biomass & 18.86 \(\pm\) 0.01 & 25.21 \(\pm\) 0.41 & 19.50 \(\pm\) 0.38 & 20.12 \(\pm\) 0.27 \\ Protein in biomass (g/g) & 0.46 \(\pm\) 0.02 & 0.47 \(\pm\) 0.03 & 0.45 \(\pm\) 0.01 & 0.45 \(\pm\) 0.02 \\ Ethanol yield (g/g) 1  & 0.22 \(\pm\) 0.00 & 0.12 \(\pm\) 0.00 & 0.14 \(\pm\) 0.00 & 0.20 \(\pm\) 0.01 \\ Biomass yield (g/g) 1  & 0.12 \(\pm\) 0.00 & 0.17 \(\pm\) 0.01 & 0.13 \(\pm\) 0.01 & 0.13 \(\pm\) 0.01 \\ \hline \end{tabular}
\end{table} 
Table 2: Comparison of the fermentation effects by four edible fungi strains after 72 h cultivation on bread hydrolysate media. The composition of the medium for the second fermentation stage is shown in Table 3. The stillage did not contain a significant amount of undissolved solids, which might have affected the biomass estimation. The comparison of the stillage fermentation effects by _N. intermedia_ and _A. oryzae_ is shown on Figure 2. It was observed that both fungi utilized dextrin at a similar rate to a final concentration of 14.2 \(\pm\) 0.7-14.8 \(\pm\) 0.1 g/L, with an average consumption of 26%. No significant differences were observed for the profile of multitorise utilization for both studied strains. _N. intermedia_ showed higher efficiency of maltose and glucose utilization from the medium than _A. oryzae_. For both strains, a small (0.2-0.6 g/L) increase in maltose concentration was observed after the first day of fermentation. After that, _N.