Microcalorimetric research on recombinant Escherichia coli with high production of polyhydroxyalkanoates (PHAs)

Abstract

The thermogenic curves of metabolism of the four strains of Escherichia coli pUC19cab/JM109, pUC19cab/XL-IBlue, JM109 and XL-IBlue were determined using the LKB-2277 BioActivity Monitor and the ampoule method at 37?XC. The pUC19cab/JM109 and pUC19cab/XL-IBlue are recombinant E. coli strains bearing the same foreign plasmid pUC19cab, which confers the ability to produce polyhydroxyalkanoates (PHAs). The yield of PHAs of pUC19cab/XL-IBlue was higher than that of pUC19cab/JM109. XL-IBlue and JM109 were the host bacteria. The heat flow of these strains was XL-Blue?JM109>pUC19cab/JM109>pUC19cab/XL- IBlue. These results indicate an obvious interrelation between the PHAs production and the heat flow rate of E. coli strains.