Synthesis and Characterization of Polyesters Produced by Paracoccus sp. 12-A from Formic Acid

Paracoccus sp. 12-A was isolated from a sewage sample as a facultative formate-utilizing bacterium. The cells were harvested in the stationary growth phase (3 days) by centrifugation (7000 g) at 4 degree C. After washing with sterilized water, the cells were lyophilized to yield the dry cells. The polymer was extracted from the lyophilized cells in a Soxlet extractor with chloroform, filtered through a cotton plug, and precipitated from chloroform by adding 10 volumes of n-hexane. The polymer obtained was redissolved in chloroform, filtered, and reprecipitated. Polyester contents varied with batches and the highest level that occurred in this study was about 60% of the dry cell weight.