# The Effect of LEDs on Biomass and Phycobiliproteins Production in Thermotolerant _Oscillatoria_ sp.
## 4 Discussion  
Light quality is one of the most critical variables in microalgal and cyanobacterial industrial biomass production and specific metabolites [30]. In the case of biomass production using cyanobacterial strains, the application of LEDs with specific wavelengths has proved an interesting alternative (Table 1). While it is important from a research point of view to identify the best wavelength using LEDs to produce phycocyanin, it is also essential for determining the possibility of scaling up this type of technology to industrial production systems. Worldwide, most microalgae and cyanobacteria production plants use sunlight for their operations; however, to maintain high productivity, it is necessary to avoid the uncertainty generated by adverse environmental conditions that can substantially reduce the photosynthetic efficiency, and therefore reduce the company's total profits. Thus, the search for ways to improve photosynthetic efficiency throughout the day is critical for sustainability in producing microalgae and cyanobacteria of commercial interest. Figure 7: The concentration of phycocyanin (C-PC) (**a**), alophycocyanin (APC) (**b**), and phycoerythrin (PE) (**c**) and their purity (**d–f**) different photoperiods of white/red:blue LEDs. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Strain**} & \multicolumn{2}{c}{**LED**} & \multicolumn{2}{c}{**Biomass**} & \multicolumn{2}{c}{**PBPs**} & \multirow{2}{*}{**Reference**} \\ \cline{2-2} \cline{5-8}  & **LEDs Radiation Color** & \(\boldsymbol{\mu}\)**mol m\({}^{-2}\) s\({}^{-1}\)** & **Photoperiod** & **(g/L)** & **Concentration (mg/L)** & **Type** & \\ \hline  & & 50 & N/A \({}^{1}\) & 0.7 & 91 & C-PC & [47] \\ _Arthospira_ & White \({}^{*}\) & 70 & 12:12 & 3.2 & 1.1 & A-PC & [48] \\ sp. & & 3200 & 24:0 & 1.77 & 103 & & [23] \\  & Red & 500 & 24:0 & 1.77 & 103 & & [23] \\  & White & 350 & 12:12 & 0.78 & 120 & & [49] \\  & Blue & 350 & 12:12 & 0.78 & 120 & & [49] \\  & Red & 10 & 12:12 & 0.78 & 0.4 & PE & [30] \\  & & & & 1.57 & & & \\ _A. maxima_ & White & & & 3.9 & 351 & & \\  & Blue & & & 3.7 & 481 & C-PC & \\  & Orange & & & & 1.2 & 24 & A-PC & \\  & & 80 & 24:0 & & 84 & & \\  & Orange & & & & 119 & C-PC & [50] \\  & Orange & & & & 1.7 & 40 & & \\  & White & & & & 3.4 & 340 & & \\  & Blue & & & & 288 & C-PC & \\  & Blue & & & & 3.6 & 90 & A-PC & \\  & Red & & & & 0.4 & 40 & & \\  & Red & & & 0.6 & 70 & & \\  & White & & & & 0.6 & 50 & C-PC & [51] \\  & Yellow & & & & 0.5 & 30 & & \\  & Red & & & & 3.9 & 17.6\% \(w/w\) & & \\  & Blue & 2500 \({}^{2}\) & & & 3.6 & 2.9\% \(w/w\) & C-PC & [52] \\  & White \({}^{*}\) & & & & 2.8 & 15.7\% \(w/w\) & & \\  & White & & & N/A \({}^{1}\) & 0.8 & 112 & & \\  & Blue & 1000 & & 0.2 & 30 & & \\  & Green & & & 0.9 & 126 & & [53] \\  & Red & & & 1 & 140 & & \\  & Yellow & 250 & 12:12 & 6.6 & 1300 & & \\  & Red:Blue (3:1) & 350 & 16:8 & 5 & 700 & & \\  & White & 300 & N/A \({}^{1}\) & 6.7 & 1072 & & [55] \\ _A. platensis_ & Natural light with Filtered Red & 60 & 12:12 & 0.7 & 198 & C-PC & [56] \\  & Natural light with Filtered Blue & 100 & & 0.5 & 144 & & \\  & Red & 700 & & 0.6 & 60 & & \\  & Blue & 1050 & N/A \({}^{1}\) & 0.4 & 5 & & [57] \\  & Red & & & 0.36 & 54 & & \\  & White & & & 0.21 & 30 & & \\  & Yellow & 3000 & 12:12 & 0.1 & 14 & & [58] \\  & Green & & & & 0.12 & 19 & \\  & Blue & & & 0.05 & 6 & & \\  & Blue & 75 & & 3.1 Globally, there are two industrial examples worth mentioning. The first is the company, Algalif ([[https://algalif.is](https://algalif.is)]([https://algalif.is](https://algalif.is)); accessed on 12 November 2022), located in Iceland. Algalif is recognized worldwide as the most sustainable microalgae producer. They use ultra-pure glacier water to produce _Haematococcus pluvialis_ and use geothermal energy for its operation. This company only makes astaxanthin indoors using LEDs tuned for cell growth and carotenogenesis. This allows Algalif to create high-quality astaxanthin year-round without relying on environmental changes.