A PROCESS FOR THE RECOVERY OF POLY(HYDROXYALKANOATES) FROM PSEUDOMONADS .1. SOLUBILIZATION

Poly(hydroxyalkanoates) (PHAs) are bacterial storage polyesters, curre ntly receiving much attention because of their potential as biodegrada ble and renewable plastics. Well known are poly(hydroxybutyrate) and i ts copolymers with hydroxyvalerate, which have been commercialised und er the trademark Biopol. In addition to these rigid materials, the ela stomeric medium-chain-length PHAs (mcl-PHAs) from fluorescent Pseudomo nads are now emerging. Here we describe the development of a non-solve nt based process for the recovery of mcl-PHAs from the biomass. This f irst paper addresses a procedure to solubilize the biomass, so that it can be separated from the particulate mcl-PHA. The solubilization pro cedure, involving heat, protease and detergent, leaves the peptidoglyc an intact, which facilitates the separation. The purity of the resulti ng mcl-PHA exceeds 95%. In a subsequent paper, we utilize the solubili zation procedure in a downstream process and we discuss the economics of the corresponding mcl-PHA production.