## 3 Results and Discussion
### Biochemical Composition
#### 3.4.3 Pigment Composition
\begin{table}
\begin{tabular}{c c c} \hline \hline
**FAME \%** & **2.5-m\({}^{3}\) PBR** & **10-m\({}^{3}\) PBR** \\ \hline C14:0 & 0.76 \(\pm\) 0.09 \({}^{\text{a}}\) & 2.88 \(\pm\) 0.87 \({}^{\text{b}}\) \\ C16:4\(n\)-3 & 23.65 \(\pm\) 2.20 \({}^{\text{a}}\) & 21.94 \(\pm\) 1.87 \({}^{\text{a}}\) \\ C16:3\(n\)-3 & 4.15 \(\pm\) 0.40 \({}^{\text{a}}\) & 2.75 \(\pm\) 0.47 \({}^{\text{b}}\) \\ C16:2n-6 & 0.73 \(\pm\) 0.08 \({}^{\text{a}}\) & 0.90 \(\pm\) 0.04 \({}^{\text{a}}\) \\ C16:1 & 2.59 \(\pm\) 0.23 \({}^{\text{a}}\) & 2.70 \(\pm\) 0.59 \({}^{\text{a}}\) \\ C16:0 & 15.24 \(\pm\) 1.60 \({}^{\text{a}}\) & 19.29 \(\pm\) 0.73 \({}^{\text{b}}\) \\ C18:4\(n\)-3 & 8.61 \(\pm\) 1.15 \({}^{\text{a}}\) & 8.83 \(\pm\) 2.43 \({}^{\text{a}}\) \\ C18:3\(n\)-3 & 31.40 \(\pm\) 2.80 \({}^{\text{a}}\) & 27.58 \(\pm\) 1.18 \({}^{\text{a}}\) \\ C18:3\(n\)-6 & 3.22 \(\pm\) 1.26 \({}^{\text{a}}\) & 3.21 \(\pm\) 0.69 \({}^{\text{a}}\) \\ C18:2n-6 & 2.94 \(\pm\) 0.78 \({}^{\text{a}}\) & 3.75 \(\pm\) 0.53 \({}^{\text{a}}\) \\ C18:1 & 5.34 \(\pm\) 0.34 \({}^{\text{a}}\) & 6.27 \(\pm\) 0.76 \({}^{\text{a}}\) \\ C18:0 & 1.37 \(\pm\) 0.56 \({}^{\text{a}}\) & 2.71 \(\pm\) 1.06 \({}^{\text{a}}\) \\ \(\Sigma\)SFA & 17.37 \(\pm\) 2.42 \({}^{\text{a}}\) & 23.92 \(\pm\) 3.54 \({}^{\text{a}}\) \\ \(\Sigma\)MUFA & 7.93 \(\pm\) 0.04 \({}^{\text{a}}\) & 8.97 \(\pm\) 1.35 \({}^{\text{a}}\) \\ \(\Sigma\)PUFA & 74.70 \(\pm\) 2.46 \({}^{\text{a}}\) & 67.10 \(\pm\) 3.30 \({}^{\text{b}}\) \\ \(\Sigma\)_n-3_ & 67.81 & 61.10 \\ \(\Sigma\)_n-6_ & 6.89 & 7.86 \\ \(\Sigma\)_n-6_ & 0.10 & 0.13 \\ PUFA/SFA & 4.30 & 2.81 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Fatty acid methyl esters (FAME) profile of _Chlorococcus amblystomatis_ biomass grown in 2.5- and 10-m\({}^{3}\) tubular photobioreactors (PBR). Different letters indicate significant differences between reactors. Values are given as means \(\pm\) standard deviation (_n_ = 3). at 0.055-m\({}^{3}\) PBR) and _Chlorococcus citrforme_ (7.2 mg:g\({}^{-1}\) at laboratory-scale) [50]. Therefore, _C. amblystomatis_ could be a promising lutein source, since the biomass produced in the 2.5-m\({}^{3}\) PBR reached significantly high contents (\(>5\) mg:g\({}^{-1}\)). Lutein is largely consumed as a feed additive in aquaculture and as a food colorant. Despite this, as it is an essential component for the macula lutea in the eye retina and lens, and since lutein from microalgae (E161g) was approved as a color additive in the EU and USA, another feasible application might be within the realm of the pharmaceutical industry [10; 44; 50]. In the eastern world, the percentage of people with Age-Related Macular Degeneration (ADM) disease is high and the recommended intake of lutein is 6 mg daily, which might often be achieved via ingestion of food supplements [44; 50]. \(\beta\)-carotene is the second most abundant carotenoid in _C. amblystomatis_ biomass; however, its contents are lower in comparison with the main natural producer of this carotenoid, _Dunaliella salina_ (Chlorophyta) (11-21 mg:g\({}^{-1}\)) [51]. This pigment holds an important nutritional use due to its ability to act as provitamin A, increasing the vitamin A production in the organism [44]. The great demand of \(\beta\)-carotene by the food, pharmaceutical, and cosmetic industries has mainly been met by production by chemical synthesis; however, the demand for natural sources is increasing, holding an estimated market size of 10 to 100 tons per year and a market value of \(>750\) \(\upxi\) kg\({}^{-1}\)[3]. In addition, _Chlorococcus_ microalgae have been reported to be capable of producing about 18 mg:L\({}^{-1}\) of astaxanthin and about 45 mg:L\({}^{-1}\) of total secondary carotenoids, upon the induction of the biosynthesis and accumulation of these pigments. _Haematococcus_ (Chlorophyta), the main astaxanthin-producer (15-30 mg:g\({}^{-1}\)) under outdoor conditions, produces only about 6.6 mg:L\({}^{-1}\) of secondary carotenoids.