## 3 Results
### Fungal Strain Selection for Efficient Ethanol and Biomass Production  
The final effects of 72 h cultivation of four studied fungal strains are presented in Table 2. It was observed that _N. intermedia_ was the best ethanol producer amongst the studied strains; however, it produced the lowest amount of biomass. The final ethanol titer for this strain reached 4.16% _v/v. A. oryzae_ cultivation resulted in the highest biomass yield, while producing the least ethanol of all the fungi tested. It was observed that all of the fungal strains resulted in considerable amounts of unfermented sugars ranging 40.48-82.10 g/L in total, which resulted in the sugar consumption ranging approx. 37-69% from the initial medium. _N. intermedia_, _A. oryzae_ and _M. indicus_ were able to hydrolyze the dextrin from the bread hydrolysate to glucose, which was the most abundant sugar remaining after cultivations. In the case of _R. oryzae_, dextrins were found as the most abundant carbohydrate in the medium followed by maltose. This suggests that the saccharifying enzyme produced by this strain is \(\beta\)-amylase, while for other strains it is glucoamylase. Additionally, _R. oryzae_ was the only strain able to produce lactic acid during the fermentation; other fungi utilized the lactate present in the medium from the beginning. _M. indicus_ was found to produce the highest glycerol amount, producing nearly twice as much as the rest of the fungi. The biomass produced by all of the fungal strains had a very high protein content at approx. 46%, which suggests that it could be used as an alternative protein source for human consumption. It should be noted that the biomass harvested after each cultivation inevitably contained residual particulate matter present in the hydrolysate from the beginning by entanglement by the fungal mycelium. Additionally, some parts of the particulates were most probably partially hydrolyzed by the enzymes produced by fungi. Therefore, it is very difficult to predict the exact fungal biomass yield from such media; however, from the practical point of view, since the raw material used in this study was food-grade, any remaining particles that were entangled by the fungal biomass would, rather, not be accounted as food contaminants; thus, it would be consumer safe.  
\begin{table}
\begin{tabular}{c c} \hline
**Component** & **Concentration (g/L)** \\ \hline Dextrin (DP4+) & 95.36 \(\pm\) 6.28 \\ Maltotriose & 14.57 \(\pm\) 0.83 \\ Maltose & 14.63 \(\pm\) 0.43 \\ Glucose & 5.52 \(\pm\) 0.03 \\ Total dissolved carbohydrates & 130.08 \(\pm\) 7.52 \\ Lactic acid & 0.19 \(\pm\) 0.06 \\ Glycerol & 0.12 \(\pm\) 0.07 \\ Dissolved solids & 140.13 \(\pm\) 1.13 \\ Undissolved solids & 17.68 \(\pm\) 0.66 \\ \hline \end{tabular} Results are average values \(\pm\) one standard deviation (\(n\) = 2).  
\end{table}
Table 1: Physicochemical features of bread hydrolysate used in this study.  
Due the fact that none of the studied fungal strains was able to utilize most of the dissolved sugars, it was decided to conduct a two-stage fermentation in which, in the second stage, the liquid residue remaining after the distillation (stillage) of the fermented bread hydrolysate would be subjected to the second fungal cultivation. The screening experiment proved that _N. intermedia_ is the highest ethanol producer, so it was chosen for the first fermentation stage and studied in detail. For the second fermentation, two strains were chosen: _N. intermedia_ to maximize ethanol yields and _A. oryzae_ to improve edible biomass production.