title: Nitrogen balancing and xylose addition enhances growth capacity and protein content in Chlorella minutissima cultures.
abstract: 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 (12.7×10(6)cellsmL(-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.
authors.affiliation: College of Chemical and Food Engineering, Federal University of Rio Grande, Laboratory of Biochemical Engineering, Rio Grande, RS, Brazil.
authors.forename: B C B
authors.initials: BC
authors.lastname: Freitas
authors.affiliation: Landscape, Environment, Agriculture and Food - LEAF Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Portugal.
authors.forename: M G
authors.initials: MG
authors.lastname: Esquível
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: R G
authors.initials: RG
authors.lastname: Matos
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: C M
authors.initials: CM
authors.lastname: Arraiano
authors.affiliation: College of Chemical and Food Engineering, Federal University of Rio Grande, Laboratory of Microbiology and Biochemistry, Rio Grande, RS, Brazil.
authors.forename: M G
authors.initials: MG
authors.lastname: Morais
authors.affiliation: College of Chemical and Food Engineering, Federal University of Rio Grande, Laboratory of Biochemical Engineering, Rio Grande, RS, Brazil. Electronic address: jorgealbertovc@terra.com.br.
authors.forename: J A V
authors.initials: JA
authors.lastname: Costa
mesh_terms: D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods; D002708:Chlorella / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D050356:Lipid Metabolism; D058086:Microalgae / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D014994:Xylose / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D014994:Xylose; D012273:Ribulose-Bisphosphate Carboxylase; D009584:Nitrogen
keywords: AtpB; Microalgae; Nitrogen; Rubisco; Xylose