Preparation of a bacterial polyester with carboxy groups in side chains

Unsaturated biopolyesters were produced by Pseudomonas oleovorans from tno mixtures of sodium octanoate and 10-undecenoic acid (90:10 and 80:20 mol/mo l) as a reserve of carbon and energy. Chemical modification of double bonds into carboxyl groups carried out with potassium permanganate (KMnO4). Oxid ation reaction was proved by H-1 and C-13 NMR spectroscopy. Molecular weigh ts of modified biopolyesters were not highly affected by the oxidation reac tion. Hydrophilicity was entranced: polyester containing 25 % of repeating units pendant carboxylic acid end groups was soluble in polar solvents such as methanol. dimethylsulfoxide or a 85:15 (v/v) acetone 'water mixture. Mo reover. the presence of carboxy) pendant groups was important with respect to the hydrolytic degradation. A fast hydrolysis was observed at pH = 11 in 24 hours for the carboxylated modified polyester containing 25 % of carbox yl groups. (C) 2001 Academie des sciences / Editions scientifiques et medic ales Elsevier SAS.