Appl Microbiol Biotechnol (1995) 43:880-886 © Springer-Verlag 1995 M. F. A. Rodrigues • L. F. da Silva J. G. C. Gomez • H. E. Valentin • A. Steinbiichel Biosynthesisof poly (3-hydroxybutyric acid co-3-hydroxy-4-pentenoic acid) from unrelated substrates by Burkholderia sp. Received: 28 December 1994/Accepted: 4 January 1995 Abstract From soil, two strains of Burkholderia sp. were isolated that synthesized and accumulated a copolyester of 3-hydroxybutyric acid and 3-hydroxy- 4-pentenoic acid from single, unrelated carbon sources such as surcose or gluconate. Strain IPT77B, for in- stance, accumulated from gluconate poly(3-hydroxy- butyric acid co-3-hydroxy-4-pentenoic acid) up to 70% (w/w) of the cellular dry matter, and 3-hydroxy-4-pen- tenoic acid contributed up to 6.9 mol 100/mol constitu- ents. The occurrence of the constituent with the vinyl pendant group in the polyester was confirmed by gas- chromatographic and nuclear magnetic resonance analysis. Introduction Many bacteria are able to synthesize and to accumulate polyesters of a wide range of different hydroxyalkanoic acids as a storge compound for carbon and/or energy (Anderson and Dawes 1990; Steinbfichel 1991). These polyhydroxyalkanoic acids (PHA) are biodegradable and represent enantiomeric thermoplastics or elas- tomers; they are therefore currently being considered by the industry for various applications in medicine, agriculture and other areas (Holmes 1985; Hocking and M. F. A. Rodrigues • L. F. da Silva • J. Gregorio C. Gomez Instituto de Pesquisas Technol6gicas do Estado de S. Paulo S/A - IPT, Caixa Postal 7151, CEP 01064-970, S~o Paulo, Brazil H. E. Valentin Institut fiir Mikrobiologie der Georg-August-Universitiit G6ttingen, Grisebachstrasse 8, D-37077 GSttingen, Germany A: Steinbiichel ([]) Institut ffir Mikrobiologie der Westf~ilischen Wilhelms-Universit~it Mi.inster, Corrensstrasse 3, D-48149 Miinster, Germany Marchessault 1994). A copolyester of 3-hydroxy- butyric acid (3HB) and 3-hydroxyvaleric acid (3HV) is already biotechnologically produced by Zeneca Bioproducts on an industrial scale, and the material is distributed under the trade name Biopol (Byrom 1990). Although approximately 90 different hydroxyal- kanoic acids have been detected in these microbial polyesters (Steinbiichel and Valentin 1995), only very few of them are incorporated into the polyester from renewable resources or from other cheap carbon sour- ces. Most of these hydroxyalkanoic acids are only in- corporated if special precursor substrates, which are often rather expensive and/or toxic to the cells, are provided as a carbon source to the bacteria. Mostly, only some Gram-positive bacteria, such as Rhodococ- cus tuber (Haywood et al. 1991), for example, and a mutant of Alcaligenes eutrophus, which is altered in the regulation of the biosynthesis of branched-chain amino acids (Steinbiichel and Pieper 1992), are able to synthesize poly(3HB-co-3HV) from single, unrelated substrates such as glucose or gluconic acid. In addition, pseudomonads, belonging to the rRNA homology group I, synthesize PHA consisting of saturated 3-hydroxyalkanoic acids of medium chain-length such as 3-hydroxydecanoic acid (Haywood et al. 1990; Timm and Steinbiichel 1990) as well as of unsaturated 3-hydroxyalkanoic acids of corresponding chain length (Huijberts et al. 1992). One example of the synthesis of a new PHA from a precursor substrate is a tercopolyester consisting of 3HB, 3HV and 3-hydroxy-4-pentenoic acid (3HPA4), which is synthesized by Rhodospirillum rubrum if the cells are cultivated anaerobically in the light in the presence of 4-pentenoic acid (Lenz et al. 1990; Ulmer et al. 1994). In this study, we describe the accumula- tion of a copolyester consisting of 3HB and 3HPA4 from glucose and other simple substrates by two recently isolated bacteria that belong to the genus Burkholderia.