"Exploratory analysis of a photobioreactor for microalgae culture for different biotechnological applications"

IGNACIO NIIZAWA; ALEJANDRO RAUL TROMBERT; JOSUE MIGUEL HEINRICH; FAUSTO ADRIAN BOTTA; HORACIO ANTONIO IRAZOQUI

Praga

Congreso; “19th International Congress of Chemical and Process Engineering CHISA 2010 / 7th European Congress of Chemical Engineering ECCE-7”; 2010

Cultivation and isolation of microalgal metabolites has led to increasing commercial interest in their use for producing valuable raw materials for food, feed, cosmetics, pharmaceuticals, and biodiesel, as well as for mitigation of pollution (bio-remediation and CO2 fixation from the environment). Compared with open systems (open ponds, lagoons), photo-bio-reactors (PBRs) have distinct advantages but in view of potential applications, development of a more controllable, economical, and efficient closed culturing system is needed. In the present work we evaluate the effect of light intensity and photoperiods (light/darkness alternation cycles: 12/12 h, 16/8 h and 24/0 h) over biomass production by a model organism (Scenedesmus quadricauda) in a bench scale PBR. Independently of the photoperiod, the higher productivity was reached under the higher light intensity condition. Using lower wall PBR intensity, cultures achieve a stationary growth phase, whereas at the same time, cultures under a higher intensity, still in logarithmic growth phase. To evaluate the potential use of Scenedesmus quadricauda as raw material for biodiesel production we determine its lipid content by Bligh and Dyer method. We assay several alternatives to carry out the lipid extraction from this microalga: freezing at -20°C, autoclave, acid pretreatment -HCl 1N-, showing this last one the best performance. Due to its lipid content (17.16%), Scenedesmus quadricuda owns to an intermediate lipid content group. The use of microalgal biomass for food industry needs –among others requirements- the determinations of its protein content. This quantification was realised through the Kjeldahl method and showed a low protein content (24.3 %).