This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bertrand, J.-L. Articles by Chavarie, C. Search for Related Content PubMed PubMed Citation Articles by Bertrand, J.-L. Articles by Chavarie, C. Agricola Articles by Bertrand, J.-L. Articles by Chavarie, C.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1990 October; 56(10): 3133-3138
Copyright © 1990, American Society for Microbiology. All Rights Reserved.

Biosynthesis of Poly-ß-Hydroxyalkanoates from Pentoses by Pseudomonas pseudoflava

Département de Génie Chimique, École Polytechnique de Montréal, C.P. 6079, Succursale A, Montréal, Québec H3C 3A7, Canada

ABSTRACT

The potential of Pseudomonas pseudoflava to produce poly-ß-hydroxyalkanoates (PHAs) from pentoses was studied. This organism was able to use a hydrolysate from the hemicellulosic fraction of poplar wood as a carbon and energy source for its growth. However, in batch cultures, growth was inhibited completely at hydrolysate concentrations higher than 30% (vol/vol). When P. pseudoflava was grown on the major sugars present in hemicelluloses in batch cultures, poly-ß-hydroxybutyric acid (PHB) accumulated when glucose, xylose, or arabinose was the sole carbon source, with the final PHB content varying from 17% (wt/wt) of the biomass dry weight on arabinose to 22% (wt/wt) of the biomass dry weight on glucose and xylose. Specific growth rates were 0.58 h^–1 on glucose, 0.13 h^–1 on xylose, and 0.10 h^–1 on arabinose, while the specific PHB production rates based on total biomass ranged from 0.02 g g^–1 h^–1 on arabinose to 0.11 g g^–1 h^–1 on glucose. PHB weight-average molecular weights were 640,000 on arabinose and 1,100,000 on glucose and xylose. The absolute amount of PHB in the cells decreased markedly when nitrogen limitation was relaxed by feeding ammonium sulfate at the end of the PHB accumulation stage of the arabinose and xylose fermentations. Copolymers of ß-hydroxybutyric and ß-hydroxyvaleric acids were produced when propionic acid was added to shake flasks containing 10 g of glucose liter^–1. The ß-hydroxyvaleric acid monomer content attained a maximum of 45 mol% when the initial propionic acid concentration was 2 g liter^–1.

^* Corresponding author.