Enhancement of Phycobiliprotein Accumulation in Thermotolerant Oscillatoria sp. through Media Optimization

Abstract

Phycobiliproteins (PBPs) are a group of brilliant pigment proteins found in cyanobacteria and red algae; their synthesis and accumulation depend on several factors such as the type of strain employed, nutrient concentration, light intensity, light regimes, and others. This study evaluates the effect of macronutrients (citrate buffer, NaNO 3 , K 2 HPO 4 , MgSO 4 , CaCl 2 , Na 2 CO 3 , and EDTA) and the concentration of trace metals in BG-11 media on the accumulation of PBPs in a thermotolerant strain of Oscillatoria sp. The strain was grown in BG-11 media at 28 °C with a light:dark cycle of 12:12 h at 100 μmol m –2 s –1 for 15 days, and the effect of nutrients was evaluated using a Plackett–Burman Design followed by optimization using a response surface methodology. Results from the concentration of trace metals show that it can be reduced up to half-strength in its initial concentration without affecting both biomass and PBPs. Results from the Plackett–Burman Design revealed that only NaNO 3 , Na 2 CO 3 , and K 2 HPO 4 show a significant increase in PBP production. Optimization employed a central Non-Factorial Response Surface Design with three levels and four factors (3 4 ) using NaNO 3 , Na 2 CO 3 , K 2 HPO 4 , and trace metals as variables, while the other components of BG-11 media (citrate buffer, MgSO 4 , CaCl 2 , and EDTA) were used in half of their initial concentration. Results from the optimization show that interaction between Na 2 CO 3 and K 2 HPO 4 highly increased PBPs’ concentration, with values of 15.21, 3.95, and 1.89 (% w/w), respectively. These results demonstrate that identifying and adjusting the concentration of critical nutrients can increase the concentration of PBPs up to two times for phycocyanin and allophycocyanin while four times for phycoerythrin. Finally, the reduction in non-key nutrients’ concentration will reduce the production costs of colorants at an industrial scale and increase the sustainability of the process.

Cotton Bed Promotes Faster Growth and Higher Biomass Production of Mat-Forming Cyanobacterium <i>Oscillatoria</i> sp.

“…physiologically active [22]. The physiologically active cyanobacteria may produce more amount of pigments, including phycocyanin [25]. However, the content of phycocyanin was determined using an equalsized mat area (1.0 cm 2 ).…”

The Circular Economy Approach to Improving CNP Ratio in Inland Fishery Wastewater for Increasing Algal Biomass Production

“…The analysis and selection of the carbon source are critical steps in the production of algal and cyanobacterial biomass; the correct concentration of the carbon source employed will enhance the synthesis and accumulation of the metabolites of interest [58]. Most of the studies found in the literature used CO 2 as the primary carbon source; however, sodium carbonate is the preferred carbon source on different culture media such as BG11.…”

Enhancement of Metabolite Production in High-Altitude Microalgal Strains by Optimized C/N/P Ratio

“…Culture parameter optimization is a key point in the improvement of industrial algal production. Both culture media and operational conditions must be "tailored-made" for individual strains to maximize their productivity [88]. One available tool is the application of the design of experiments (DoE) [88][89][90][91][92] to improve concentrations of specific metabolites.…”

“…Both culture media and operational conditions must be "tailored-made" for individual strains to maximize their productivity [88]. One available tool is the application of the design of experiments (DoE) [88][89][90][91][92] to improve concentrations of specific metabolites. This type of experiment has been successfully applied to improve the deposition of specific metabolites in algae and cyanobacteria before [93][94][95][96][97][98], especially in the selection of the carbon and nitrogen sources and their specific concentrations.…”