Fed-batch strategy for enhancing cell growth and C-phycocyanin production of Arthrospira (Spirulina) platensis under phototrophic cultivation

• Arthrospira platensis WH879 shows high potential as an C-phycocyanin producer.
• The average irradiance affects C-PC content and cell growth rate in an opposite way.
• Controlling a lower nitrogen level was more favorable for C-PC accumulation.
• Fed-batch cultivation with medium feeding effectively enhanced the C-PC production.

The C-phycocyanin generated in blue-green algae Arthrospira platensis is gaining commercial interest due to its nutrition and healthcare value. In this study, the light intensity and initial biomass concentration were manipulated to improve cell growth and C-phycocyanin production of A.platensis in batch cultivation. The results show that low light intensity and high initial biomass concentration led to increased C-phycocyanin accumulation. The best C-phycocyanin productivity occurred when light intensity and initial biomass concentration were 300 μmol/m2/s and 0.24 g/L, respectively. The fed-batch cultivation proved to be an effective strategy to further enhance C-phycocyanin production of A.platensis. The results indicate that C-phycocyanin accumulation not only requires nitrogen-sufficient condition, but also needs other nutrients. The highest C-phycocyanin content (16.1%), production (1034 mg/L) and productivity (94.8 mg/L/d) were obtained when using fed-batch strategy with 5 mM medium feeding.