Bacterial production of polyesters bearing phenoxy groups in the side chains, 1. Poly(3‐hydroxy‐5‐phenoxypentanoate‐co‐3‐hydroxy‐9‐phenoxynonanoate) from Pseudomonas oleovorans

The production of phenoxy‐substituted poly(3‐hydroxyalkanoates) (PHA) by Pseudomonas oleovorans was investigated. 11‐Phenoxyundecanoic acid was used as a single carbon source for the bacterial culture. At the maximum growth rate of the culture, the cells were isolated by centrifugation. The cells were lyophylized and then extracted with trichloromethane, yielding a comb‐like copolyester. Methanolysis of this polyester was performed to characterize the incorporated hydroxyacids. This proved the polyester to be a copolymer: poly(3‐hydroxy‐5‐phenoxypentanoate‐ co ‐3‐hydroxy‐9‐phenoxynonanoate) ( 5 ; 6:1 mole ratio). GPC measurements with polystyrene as standard indicated M n values of approximately 76 000 and a molecular weight distribution index of M w / M n = 2,3. The copolyester showed a glass transition at 14°C.