EXTRACTION OF POLY-3-HYDROXYBUTYRATE USING CHLORINATED SOLVENTS

Recovery of poly-3-hydroxybutyrate (PHB) in three chlorinated solvents with or without acetone pretreatment and degradation of extracted PHB (99% pure) in hot chloroform were studied. When lyophilized Alcaligen es eutrophus biomass was used, the best results were obtained with ace tone pretreatment and solvent reflux for 15 min in methylene chloride or chloroform. Recovered PHB had a 95% purity and molecular weights (M (w)) of 1,050,000 and 930,000 g/mol respectively. Further heating resu lted in a serious M(w) loss at reflux temperatures. Degradation of ext racted PHB at 110-degrees-C in chloroform was due to random and chain- end scission, the former being predominant.