title: Protein measurements of microalgal and cyanobacterial biomass.
abstract: The protein content of dry biomass of the microalgae Porphyridium cruentum, Scenedesmus almeriensis, and Muriellopsis sp. and of the cyanobacteria Synechocystis aquatilis and Arthrospira platensis was measured by the Lowry method following disruption of the cells by milling with inert ceramic particles. The measurements were compared with the Kjeldahl method and by elemental analysis. The nitrogen-to-protein conversion factors for biomass obtained from exponentially growing cells with a steady state doubling time of approximately 23 h were 5.95 for nitrogen measured by Kjeldahl and 4.44 for total nitrogen measured by elemental analysis. The protein content in dry biomass ranged from 30% to 55%. The above conversion factors are useful for estimating the protein content of microalgal biomass produced in rapid steady state growth as encountered in many commercial production processes.
authors.affiliation: Department of Chemical Engineering, University of Almería, E04120 Almería, Spain.
authors.forename: Cynthia Victoria González
authors.initials: CV
authors.lastname: López
authors.forename: María del Carmen Cerón
authors.initials: Mdel C
authors.lastname: García
authors.forename: Francisco Gabriel Acién
authors.initials: FG
authors.lastname: Fernández
authors.forename: Cristina Segovia
authors.initials: CS
authors.lastname: Bustos
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Chisti
authors.forename: José María Fernández
authors.initials: JM
authors.lastname: Sevilla
mesh_terms: D020418:Algal Proteins / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D018533:Biomass; D002417:Cattle; D000458:Cyanobacteria / Q000378:metabolism*; D009584:Nitrogen / Q000032:analysis; D044665:Porphyridium / Q000378:metabolism*; D012015:Reference Standards; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D020418:Algal Proteins; D001426:Bacterial Proteins; D012710:Serum Albumin, Bovine; D009584:Nitrogen