Nitrogen balancing and xylose addition enhances growth capacity and protein content in Chlorella minutissima cultures

• Published in: Bioresource technology 2016-10, Vol.218, p.129-133
• Main Authors: Freitas, B.C.B., Esquível, M.G., Matos, R.G., Arraiano, C.M., Morais, M.G., Costa, J.A.V.
• Format: Article
• Language: English
• Subjects: AtpB; Cell Count; Cell Culture Techniques - methods; Chlorella - drug effects; Chlorella - growth & development; Chlorella - metabolism; Chlorophyll - metabolism; Lipid Metabolism; Microalgae; Microalgae - drug effects; Microalgae - growth & development; Microalgae - metabolism; Nitrogen; Nitrogen - metabolism; Photosynthesis; Photosystem II Protein Complex - metabolism; Ribulose-Bisphosphate Carboxylase - metabolism; Rubisco; Xylose; Xylose - metabolism; Xylose - pharmacology
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2016.06.059

•D-Xylose can be considered a new carbon source for microalgae.•Rubisco and AtpB are sensitive to nitrogen concentration in Chlorella minutissima.•D-Xylose affects the content of Rubisco in Chlorella minutissima. This study aimed to examine the metabolic changes in Chlorella minutissima cells grown under nitrogen-deficient conditions and with the addition of xylose. The cell density, maximum photochemical efficiency, and chlorophyll and lipid levels were measured. The expression of two photosynthetic proteins, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and the beta subunit (AtpB) of adenosine triphosphate synthase, were measured. Comparison of cells grown in medium with a 50% reduction in the nitrogen concentration versus the traditional medium solution revealed that the cells grown under nitrogen-deficient conditions exhibited an increased growth rate, higher maximum cell density (12.7×106cellsmL−1), optimal PSII efficiency (0.69) and decreased lipid level (25.08%). This study has taken the first steps toward protein detection in Chlorella minutissima, and the results can be used to optimize the culturing of other microalgae.