Production of Poly(3-hydroxyalkanoates) Containing Aromatic Substituents by Pseudomonas oleovorans

Abstract

Pseudomonas oleovorans was grown separately on 5-(4'-tolyl)valeric acid, 5-(4'-ethylphenyl)-valeric acid, 5-(4'-biphenyl)valeric acid, and 8-(4'-tolyl)octanoic acid either as the sole carbon source or as a coefeed with either nonanoic acid or 5-phenylvaleric acid. For polymer production, 5-(4'-tolyl)valeric acid was the most effective growth substrate of the five. It resulted in the production of poly-3-hydroxy-5-(4'-tolyl)valerate, a crystalline polymer with a glass transition temperature of 18 °C and a melting transition of 95 °C. This poly(3-hydroxyalkanoate) (PHA) is apparently the first example of a crystalline aromatic-containing bacterial PHA. When P. oleovorans was cofed an equimolar mixture of 5-phenylvaleric acid and 5-(4'-tolyl)valeric acid, the polymer produced contained 36 mol % of 3-hydroxy-5-phenylvalerate and 64 mol % of 3-hydroxy-5-(4'-tolyl)valerate, and it did not crystallize.