TIBURCIO, V. P.; http://lattes.cnpq.br/1823540891617401; TIBÚRCIO, Viviane Pereira.
Résumé:
The search for viable energy alternatives, low cost, sustainable and can replace the use
of fossil fuels has increased. In this context, biofuels derived from microalgae become a
promising option either from the economic point of view as from the environmental
point of view. The cultivation of microalgae produce higher amount of biomass in a
short time and require large areas for their production as with sugarcane used for
ethanol production, or soybean in the case biodiesel. This study aimed to characterize
the potential for production of fatty acids from microalgae isolated from the semiarid
region of the state of Paraiba kept growing in monospecific cultures of microalgae bank
of LARBIM / UFPB and select potentially producing species of these compounds in
order to grow them different stress conditions in order to increase the final yield of the
fatty acids of interest for biodiesel production. The cultures were developed using the
means Zarrouk and toilet in a growth chamber at 25 ° C ± 1 ° C equipped with lighting
system, with a photoperiod of 12 hours. 12 strains included representatives of groups of
cyanobacteria and green algae were studied in seven species. The quantification of each
fatty microalgae studied acids was determined by gas chromatography. Two species
Pediastrum tetras (D121WC) and Scenedesmus acuminatus (D115WC) showed levels
of fatty acids 802.1% compared to 211.1% in soybeans compared to soybean,
respectively. Therefore these species were grown under different conditions of stress
under the same conditions of temperature and photoperiod, using photic, thermal and
nutritional stresses. At the end of each experiment were determined for each condition
tested, the levels of proteins, lipids and carbohydrates. The growth curves were avidly
by measuring in vivo fluorescence in triplicate, and all growth parameters were
analyzed for each species tested. Observed a higher rate of cell division per day in
D112Z (0.71 divisions / day) species. The levels of fatty acids in strain D121WC
increased more than twice on condition of photic stress. As for the species D115WC
was an increase in the yield of fatty acid to condition it to heat stress of 590.8%
compared to soybean. Although the two potentially important for the production of
biodiesel tested species (Pediastrum tetras and Scenedesmus acuminatus) are, it is
evident that their physiological responses to stress conditions are not the same.
