A Kinetics Studies of the Production Rhamnolipids by Pseudomonas aeruginosa LAMI from Glycerin

Abstract

in sufficient amount for the commercial exploitation. Therefore,in order to promote the emergence of this industry, it is impor-tant to establish recovery methods for polysaccharides productionwithcommercialinterest.Actuallythemainstudiesfortheproduc-tionofsulphatedpolysaccharidefractionsarecarriedoutusinglowconcentrationofHClwithreactionperiodstimesofabout1-3hours.The aim of the present work was to evaluate the sulphatedpolysaccharides (fucoidan) recovery from brown seaweeds bymicrowave-assisted extraction under different operational condi-tions. Brown seaweeds species Fucus vesiculosus and Ascophyllusnodosum from North Portugal were studied. The extraction reac-tions were performed according to experimental designs varyingthe time (1 to 11min), pressure (30 to 50 psi) and alga/water rela-tion (1/25 to 5/25g/ml). All the experiments were carried out ina microwave digestion oven MDS-2000 (CEM Corporation). Totalsugars content, monosaccharide composition and sulphated con-tent were quantified.Significant differences (p<0.05) were found varying the pres-sureandtimelevels,whilethealga/waterrelationdidnotinfluencethe extraction values in the range of values studied. The, high-est recovery index was achieved when using 50 psi during11min. The maximum yield of sulphated polymer extracted underthese conditions was similar to values reported in the literature.Monosaccharide composition analyses showed mainly the pres-ence of fucose and galactose.In conclusion, microwave-assisted extraction under short reac-tion times is an effective method in improving polymer dissolutionof sulphated polysaccharides from brown seaweeds.doi:10.1016/j.jbiotec.2010.09.508[P-I.143]Development of an empirical correlation for Newtonian andnon-Newtonianfluidsinastirredtankreactor,topredictoxygenmass transfer ratesS. Raposo, F. Azevedo, M.E. Lima-Costa