THERMAL EVALUATION OF TRANSGENIC COTTON CONTAINING POLYHYDROXYBUTYRATE

Bacterial genes responsible for the synthesis of the aliphatic polyest er compound, poly-D-(-)-3-hydroxybutrate (PHB) were introduced into co tton (Gossypium hirsutum L. Cv DP50) through particle bombardment. The resulting transgenic cotton contained PHB in the cotton fiber lumen. The presence of PHB granules in transgenic fibers resulted in measurab le changes in thermal properties. The fibers exhibited better insulati ng characteristics than natural cotton. The rate of heat uptake was hi gher and cooling slower in transgenic fibers. Thus, the transgenic fib ers had higher heat capacity and lower thermal conductivity. These res ults demonstrate that thermal properties of fibers can be enhanced by genetic engineering of cotton. Based on our preliminary studies of mix tures of PHB and cellulose powder, it appears that the biological comp osite of cellulose, PHB and, probably, bound water are necessary for t he enhanced heat uptake of transgenic fibers. The heat uptake may be i nfluenced by interactions of PHB within the fiber lumen. (C) 1998 Else vier Science B.V.