## 3 Results and Discussion
### Amino Acid Profile  
The amino acids (AA) profile of _D. viridis_ TAV01 is presented in Table 4 as well as that of other species. The highest AA content corresponds to arginine (13.0% of total AA (TAA)), followed by leucine (9.27% of TAA) and proline (8.34% of TAA). Taurine was found in a minimum amount, whereas this AA was not detected in other strains. TAV01 presented a high amount of essential amino acids (EAA) (leucine, phenylalanine, valine) and good protein quality, as indicated by an EAAI of 1.80. Observing the AA profile, similar results were reported for soy protein, whereas studies with _D. tertiolecta_, _D. salina_, spirulina, and _Chloerella_ sp. showed a lower EAA. Spirulina has a similar EAAI value, being well known for its great protein quality and as an excellent source of EAA [62]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Amino Acid** & _D. viridis_**TAV01** & _D. tertiolecta_1** & _D. salina_2** & **Spirulina 3** & _Chloerella_ sp. 4** & **Soy Protein 4** \\ \hline Alanine & 6.49 \(\pm\) 0.14 & 7.27 \(\pm\) 0.03 & nr & 7.99 & 7.90 & 5.00 \\ Arginine & 13.0 \(\pm\) 0.2 & 16.09 \(\pm\) 0.06 & nr & 6.88 & 6.40 & 7.40 \\ Aspartic Acid & 3.05 \(\pm\) 0.02 & 9.02 \(\pm\) 0.09 & nr & 9.70 & 9.00 & 1.30 \\ Cysteine & 0.74 \(\pm\) 0.02 & 1.59 \(\pm\) 0.04 & nr & 0.90 & 1.40 & 1.90 \\ Glutamic Acid & 6.04 \(\pm\) 0.2 & 12.98 \(\pm\) 0.09 & nr & 12.95 & 11.60 & 19.00 \\ Glycine & 6.13 \(\pm\) 0.01 & 5.96 \(\pm\) 0.08 & nr & 5.11 & 5.80 & 4.50 \\ Histidine * & 1.73 \(\pm\) 0.02 & 1.29 \(\pm\) 0.01 & 1.11 & 1.90 & 2.00 & 2.60 \\ Isoleucine * & 5.02 \(\pm\) 0.04 & 3.15 \(\pm\) 0.05 & 1.95 & 5.76 & 3.80 & 5.30 \\ Leucine * & 9.27 \(\pm\) 0.06 & 7.59 \(\pm\) 0.05 & 3.48 & 9.27 & 8.80 & 7.70 \\ Lysine * & 5.56 \(\pm\) 0.17 & 4.66 \(\pm\) 0.08 & 1.41 & 4.85 & 8.40 & 6.40 \\ Methionine * & 3.73 \(\pm\) 0.00 & 1.50 \(\pm\) 0.02 & 7.37 & 2.48 & 2.20 & 1.30 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Amino acids concentration (g 100 g\({}^{-1}\)) of _Dunaliella_ sp. TAV01 compared with other _Dunaliella_ spp., other microalgal species, and soy protein. Values are means \(\pm\) SEM. Transforming the data into a radial chart (Figure 4), it can be seen that the _Chlorella_ sp. is the largest lysine producer, whereas _D. salina_ showed the highest phenylalanine contents. Nevertheless, the total EAA content of _D. viridis_ TAV01 was 65% higher than the minimum amount recommended by the World Health Organization (WHO): 27.1 g 100 g\({}^{-1}\)[67]. Also, spirulina [65], one of the algae displaying consistently high protein contents, shows lower EAA values (42.51 g 100 g\({}^{-1}\)) than those of _D. viridis_ TAV01 (44.88 g 100 g\({}^{-1}\)). Furthermore, when compared to those of _D. tertioleta_ (34.78 g 100 g\({}^{-1}\)) [63], _D. salina_ (33.05 g 100 g\({}^{-1}\)) [64], _Chlorella_ sp. (42.60 g 100 g\({}^{-1}\)) [66], or soy protein (39.00 g 100 g\({}^{-1}\)), TAV01 shows a better EAA value [66]. In addition, all individual EAA contents in TAV01 were equally higher, with threonine and phenylalanine being 2.47- and 1.95-fold higher than WHO requirements, respectively, and leucine, isoleucine, and valine about 1.6-fold higher than the required level, confirming that this strain has a high-quality protein profile, which might be excellent for human consumption. Moreover, the levels of several EEAs, such as valine, methionine, threonine, and isoleucine match human nutritional needs. Although the information regarding _D. viridis_ AA contents and how the cultivation condition affects the AA profile is limited, several studies on other species have shown that stress conditions can significantly increase AA content. Studies varying the growing conditions of _D. salina_ suggest that nitrogen limitation might increase all EAA contents, which