Monday, April 19, 2010
LL Conference Facility (Hilton Clearwater Beach)
One possible application for the excess of glycerol, a byproduct of biodiesel industry is to be used as carbon and energy source for bioproducts synthesis. This work aimed to evaluate biosurfactant production from glycerol by Pseudomonas aeruginosa EQ 109 isolated from crude oil-contaminated soil. Factorial design 23 was adopted to assess the amount of biosurfactant produced, by using pH, initial concentration of biomass (X0), and initial concentration of glycerol (Glol0) as independent factors. The experiments were carried in flasks contained 100 mL of mineral medium (150 rpm at 30 ± 1ºC). Aliquots were sampled at 24, 48 and 72 h. Biosurfactant production was monitored by the emulsifying activity against aviation kerosene (Ei), glycerol consumption (GC), superficial tension reduction (STr) and final biomass (Xf). Linear models indicated the optimal conditions, as follows: to increase Ei, X0 and Glol0 were the most significant factors (Eimax, 75%), as well as the increase of the GC (GCmax, 43%) at pH=7.0. The STr reached the best correlation coefficient of the model (R2=0.96), with influence factors X0 and Glol0, at pH=7,0 (STrmax=44%). Model was not significant to Xf, however, it was influenced by pH and X0, at Glol0= 40g/L (Xf max=4,56g/L).