# Sustainable Microalgae and Cyanobacteria Biotechnology
## 4 Other Important Applications of Microalgal Biotechnology
### Additives for Animal Feeding  
The use of microalgae as nutritional additives for animal feed and human consumption, for instance, is recognized by the production of omega-3 polyunsaturated fatty acids [106]. Of all the species studied, the most widely used are the genera _Chloella_, _Tetraselmis_, _Isochrynsis_, _Pavlova_, _Phaedactylum_, _Chaetoceros_, _Nannochloropsis_, _Skeletonema_, and _Thalassioira_ for aquaculture activities, mainly because of their high nutritional content, presence of vitamins, minerals, pigments, and antioxidant compounds [107; 108]. Several microalgae such as _Aphanizomenon_, _Chloella_, and _Arthospira_, are high protein-rich species, making them essential in a world where population density continues to increase [109; 110]. Instead, lipids and highly polyunsaturated fatty acids such as docosahexaneoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) have been found in microalgae; similarly, a high concentration of linoleic and linolenic acids has been found in several species of microalgae such as _Spirulina_[111; 112]. Other essential compounds obtained from microalgae are \(\beta\)-carotene, lutein, astaxanthin, chlorophyll, phycobiliprotein, among others, such as vitamin precursors, antioxidants, immune system promoters, and anti-inflammatory agents  
\begin{table}
\begin{tabular}{l l l l l l l} \hline \hline
**Microalgal Specific** & \begin{tabular}{l} **Biomass** \\ **Productivity** \\ **mg/L/d** \\ \end{tabular} & **Carbon Source** & \begin{tabular}{l} **Metabolic** \\ **Cultivation** \\ \end{tabular} & \begin{tabular}{l} **Lipid** \\ **Content** \\ \% \\ \end{tabular} & \begin{tabular}{l} **PFA** \\ **Content** \\ **mg/g** \\ \end{tabular} & **Reference** \\ \hline _C. vulgaris_ & 137.43 & molasses & Mixotrophic & 39 & 59.7 & [94] \\ \hline _C. vulgaris_ & 91.57 & CO\({}_{2}\) & Autotrophic & 19 & 36 & [94] \\ \hline _Scenedesmus dimorphus_ & 119.25 & Sugar cane Bagasse & Mixotrophic & & 40.02 & [97] \\ \hline _Scenedesmus dimorphus_ & 140.37 & Apple-promace & Mixotrophic & 41 & 64 & [95; 96] \\ \hline _Scenedesmus dimorphus_ & 96.4-96.55 & CO\({}_{2}\) & Autotrophic & 28 & 37.65 & [95] \\ \hline _Chloerella vulgaris_ & & Sorghum bagasse & Mixotrophic & 34.4 & & [96] \\ \hline _Arthrospira platensis_ & 1330 & Sucrose & Mixotrophic & 3.68 mg/g cell & [98] \\ \hline _Arthrospira platensis_ & 153 & CO\({}_{2}\) & Autotrophic & 3.12 mg/g cell & [98] \\ \hline _Graesiella_ sp. & 170 & CO\({}_{2}\) + Glucose & Mixotrophic & 45.8 & 1.47 & [88] \\ \hline _Graesiella_ sp. & 120 & CO\({}_{2}\) & Autotrophic & 19.4 & 16.66 & [88] \\ \hline _Dictyosphaerium_ sp. & 230 & \
\begin{tabular}{l} CO\({}_{2}\) + Glucose \\ 10 g/L \\ \end{tabular} & Mixotrophic & 32 & & [99] \\ \hline _Dictyosphaerium_ sp. & 230 &
\begin{tabular}{l} CO\({}_{2}\) + Glucose \\ 20 g/L \\ \end{tabular} & Mixotrophic & 42 & & [99] \\ \hline \hline \end{tabular}
\end{table}
Table 5: Biomass and lipid productivity under different production strategies.  
have been obtained from several microalgal genera such as _Anabaena_, _Nostock_, _Botryococcus_, _Synechococcus_, _Chlamydomonas_, _Scenedesmus_, _Perietochloris_, and _Porphyridium_[113, 114]. _Nammochloropsis_ biomass has shown functional properties in the inclusion to balanced diets of the tropical edible fish _Attactosteus tropicus_, Gill 1863 [115].