Pentoses and light intensity increase the growth and carbohydrate production and alter the protein profile of Chlorella minutissima

- Xylose and arabinose increase the carbohydrate content of Chlorella minutissima.
- A low luminous intensity and the presence of pentoses affect the protein profile of Chlorella.
- Higher luminosities promote Chlorella growth in raceway reactors.
- Xylose and arabinose can be used as carbon sources for microalgal cultures.

High concentrations of carbon, which is considered a necessary element, are required for microalgal growth. Therefore, the identification of alternative carbon sources available in large quantities is increasingly important. This study evaluated the effects of light variation and pentose addition on the carbohydrate content and protein profile of Chlorella minutissima grown in a raceway photobioreactor. The kinetic parameters, carbohydrate content, and protein profile of Chlorella minutissima and its theoretical potential for ethanol production were estimated. The highest cellular concentrations were obtained with a light intensity of 33.75 µmol.m−2.s−1. Arabinose addition combined with a light intensity of 33.75 µmol.m−2.s−1 increased the carbohydrate content by 53.8% and theoretically produced 39.1 mL · 100 g−1 ethanol. All of the assays showed that a lower light availability altered the protein profile. The luminous intensity affects xylose and arabinose assimilation and augments the carbohydrate content in C. minutissima, making this microalga appropriate for bioethanol production.