Analysis and Evaluation of Antimicrobial Activity of Parietal Hemicellu-loses of Retama Raetam Roots

Abstract

Retama raetam is a halophyte shrub belonging to the Fabaceae. This medici-nal species develops a particularly important root system and is adapted to arid areas. This adaptation has accompanied by the appearance of new bio-logical functions and specific metabolites. The present work aimed to evalu-ate the antimicrobial effect of hemicelluloses (HCs). The study consisted of extracting, purifying the parietal HCs of R. raetam roots and characterizing them by thin layer chromatography (CCM), as well as by colorimetric deter-mination of total sugars. The uronic acid content of the HCs was also deter-mined. These estimations revealed that HCs were neutral PLs (arabinoxylans). The activity of this polysaccharide (PLs) was investigated against seven bacterial strains and one yeast using disc diffusion method and minimum inhibitory concentration (MIC) was also calculated. HCs of brut residu (HBR) showed a very important inhibitory effect against six bacterial strains tested with maximal inhibition zone of (19±1)mm for Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC25923) in 100 mg/ml concen-tration, but no activity against Klebsiella pneumonia (ATCC4352) and Candida albicans. In opposite, the highest inhibition zone of (16±1) mm was noticed against E.coli, in HCs of delignified residue (HDR). The MIC of HCs ranged from 8.33 to 20 mg/ml. The activity was found to be in an increasing order from the lower to higher concentration. This is a first report on antimicrobial activity of HBR and HDR from R. raetam roots.