Influence of light and temperature on growth and high-value molecules productivity from Cyanobacterium aponinum

Abstract

Cyanobacterium aponinum is a thermotolerant cyanobacterium species isolated from different thermal springs and showing potential therapeutic application thanks to the synthesis and release of exopolysaccharides with anti-inflammatory and immunomodulating properties. This work investigates the effects of temperature and light on growth rate, biomass yield, and released polysaccharides (RPS) synthesis in C. aponinum cultures. The highest biomass productivity was obtained at 40 °C (about 92 mg L−1 d−1), while the highest RPS synthesis rate (about 10 mg L−1 d−1) was detected at 35 °C. At this temperature, the influence of light intensities, between 15 and 650 μmol photons m−2 s−1, was also evaluated. C. aponinum showed the highest productivity in biomass (about 280 mg L−1 d−1) and RPS (about 20 mg L−1 d−1) at 500 μmol photons m−2 s−1. Interestingly, this strain also had the ability to accumulate other high-value compounds such as phycocyanin, zeaxanthin, and β-carotene suggesting that C. aponinum can be used for the industrial production of multiple molecules of biotechnological interest.