Kinetic and thermodynamic investigation of Arthrospira (Spirulina) platensis fed-batch cultivation in a tubular photobioreactor using urea as nitrogen source JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, HOBOKEN, v. 87, n. 11, pp. 1574-1583, NOV, 2012 BACKGROUND: Fed-batch culture allows the cultivation of Arthrospira platensis using urea as nitrogen source. Tubular photobioreactors substantially increase cell growth, but the successful use of this cheap nitrogen source requires a knowledge of the kinetic and thermodynamic parameters of the process. This work aims at identifying the effect of two independent variables, temperature (T) and urea daily molar flow-rate (U), on cell growth, biomass composition and thermodynamic parameters involved in this photosynthetic cultivation.