## 3 Results and Discussion
### Biomass Production, Sugars and Nitrogen Consumption  
Kinetic data for total sugars and nitrogen assimilation and the biomass increase of _Morchella_ species as a function of time at the four substrates with different carbon sources and C/N ratio (S-20, S-25, M-20, M-25), agitated or not, is presented in Table 2a-c. Biomass (X, g/L) production was significantly enhanced when _Morchella_ species were cultivated on molasses. Although the main component of molasses is sucrose, its effect on mycelium synthesis was weaker than that of molasses, probably due to its various nutrients (macronutrients, trace elements) other than sucrose [13; 46], as the X\({}_{\text{max}}\) values in sucrose substrates were 7.29-12.15 g/L when in molasses they were as high as 12.01-18.16 g/L. In addition, all X\({}_{\text{max}}\) values were recorded in agitated cultures on the last day of fermentation. Likewise, agitation favored biomass formation for the tested ascomycetes to a greater or lesser degree, in combination with the substrate, C/N ratio and kind of species (Table 2a-c). These results are in agreement with the perception that aeration favors mycelial growth in \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{**Molasses Characteristics**} \\ \hline Moisture & 27.0\% w/w \\ Total nitrogen & 1.8\% w/w \\ Organic matter & 44.8\% w/w \\ Total sugars & 510-530 g/L \\ Phenolic compounds & 33.25 g/L \\ pH & 5.50 \\ Density & 1.2438 g/mL \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Characteristics and specifications of molasses. liquid media [28; 47; 48; 49]. [PERSON] et al. [28] indicated that _Morchela elata_ (black morel) achieved X\({}_{\text{max}}\) value 7.1 g/L at the 20 th day of agitated culture in glucose-based media (C/N \(\sim\)20; Gl\({}_{\text{c0}}\) = 30 g/L), instead of 5.2 g/L in static culture. Also, when _Morchela esculenta_ (yellow morel) was cultivated in glucose substrate (C/N \(\sim\)20; Gl\({}_{\text{c0}}\) = 30 g/L), agitation presented a small positive effect on produced X\({}_{\text{max}}\) values (13.59 g/L), compared with static culture (12.70 g/L) [29]. Concerning the difference between yellow and black morels, the species which achieved the highest X\({}_{\text{max}}\) values on four substrates was the black one, _M. conica_ (10.85 g/L; S-20, 12.15 g/L; S-25, 18.16 g/L; M-20, 18.10 g/L; M-25). Results of [PERSON] et al. [21] in cultures with different carbon sources were similar, as yellow morels (_M. esculenta_ and _M. angusticeps_) produced less biomass than black species (_M. crassipes_ and _M. conica_). In parallel, [PERSON] et al. [50] reported high biomass production (12.6 g/L) by the black morel _M. conica_ grown on a synthetic sucrose-based medium. Between yellow morels, _M. vulgaris_ produced the second highest X\({}_{\text{max}}\) values (8.40 g/L; S-20, 11.05 g/L; S-25, 16.81 g/L; M-20, 16.92 g/L; M-25), following by _M. rotunda_ (7.95 g/L; S-20, 9.69 g/L; S-25, 16.15 g/L; M-20, 16.27 g/L; M-25). According to [PERSON] et al. [10], yellow (_M. vulgaris, M. crassipes_) and black (_M. elata, M. conica_) morels were cultivated in batch cultures under static conditions in glucose substrate (Gl\({}_{\text{c0}}\) = 30 g/L) and the produced biomass was between 9.3-11.1 g/L for the yellow morels and 9.4-14.2 g/L for the black ones, identical values obtained in the present experiments. As for the C/N ratio, its raise from 20 to 25 had a positive effect in X formation and TS consumption for sucrose substrates, either agitated or not. X\({}_{\text{max}}\) values in S-20 were from 7.29 to 10.85 g/L and 80.5-99.5% of TS\({}_{\text{con}}\), whereas in S-25 were observed higher X\({}_{\text{max}}\) values, 7.39-12.15 g/L and TS\({}_{\text{con}}\) rates show little or no further increase, 82.1-99.5%. On the contrary, in molasses substrates, X production was reduced at C/N = 25 (12.01-14.45 g/L) compared to the trials with C/N = 20 in static cultures (13.46-16.02 g/L).