Enhancement in phycobiliprotein accumulation in Aphanothece sp. using different carbon sources and flashing frequency

Cultivation of microalgae for the production of biomass and high value products is critically ties to the economic feasibility of the algal production system. In this study, we proposed the usage of exogenous carbon sources to activate the photoheterotrophic growth of the Aphanothece sp. Based on our findings, supplementation of the BG-11 media with 2 % glucose or 4 % sucrose can increase biomass production by 74.15 % (3.11 ± 0.35 g/L) and 59 % (2.83 ± 0.27 g/L), respectively. Under the photoheterotrophic growth using 2 % glucose, the production of C-PC and APC from Aphanothece sp. was increased up to 6.72 ± 0.13 mg/g fresh weight and 0.13 ± 0.01 mg/g fresh weight, respectively (chlorophyll a content up to 66.3 ± 3.2 μg/g fresh weight). Our findings also showed that, the usage of flashing frequency at the stationary growth phase of Aphanothece sp. (photoautotrophic) upregulated the concentration of C-PC and APC by 64.51 % and 46.34 %, respectively. A positive stimulus of flashing frequency on the production of the C-PC and APC from photoheterotrophic culture of Aphanothece sp. was observed. The economic analysis of supplementation of the Aphanothece sp. media with 2 % glucose can decrease the production cost of the system (g/L) by 62.81 % due to higher biomass generated by photoheterotrophic growth of Aphanothece sp. in compared to the photoautotrophic condition.