Mesquite gum:: fractionation and characterization of the gum exuded from Prosopis laevigata obtained from plant tissue culture and from wild trees

The effect of abiotic and biotic stresses in the in vitro gum production from Prosopis laevigata has been studied. The presence of autoclaved microbial biomass (MB) in combination with an incubation temperature of 35 degreesC induced the greatest gum production. In vitro and in situ gum samples from mesquite were fractionated by hydrophobic affinity chromatography. The results indicated that both gums consist of five principal fractions. The protein content of the fractions varied greatly (0.04-50.05%). For both gums, the protein content in the fractions (F) increased in the following order F2a < F1 < F2b < F3a < F3b. The monosaccharide compositions, protein contents and other analyses of whole gums also were performed. The molecular mass distribution was determined by gel permeation chromatography (GPC). Showing the existence of five components varying in molecular mass from 3.5 x 10(4) to 9.4 x 10(5). (C) 2003 Elsevier Ltd. All rights reserved.