In the recent decade, biosynthesis of the degradable biopolymers polyhydroxyalkanotes in transgenic yeasts became an important research task. Most research strategies depend on either metabolic engineering or molecular approaches. In the present work, research compared PHA biosynthesis in two types of yeasts;
Saccharomyces cerevisiae
and a non-convenient
Kloeckera spp.Yeast strains were equipped in their cytoplasm with the
phaABCRe operon containing genes
phbA, phbB and
phbC of the PHA biosynthetic pathway of
Ralstonia eutropha
, which encode â-ketothiolase, NADPH-linked acetoacetyl-CoA reductase and PHA synthase, respectively. The transgenic strains
Saccharomyces cerevisiae and
Kloeckera sp. were able to produce PHA. The maximum content of the polymer detected in the recombinant strain INVSc1/PHA1 was 2.68 % and only poly-3-hydroxybutyrate (PHB) accumulated. However, the non-conventional transgenic strain KY1/PHA was able to accumulate as maximum of 7.06 % of the copolymer poly-(3-hydroxybutyrateco-poly-3-hydroxyvalerate) (PHV). Western blot analysis confirmed expression of the
phaABCReoperonin the transgenic yeast strains. The nature of the PHA thus produced by all tested strains was analyzed by
1H and
13C nuclear magnetic resonance (NMR) spectroscopy.
