Thermokinetic change of several Bacillus thuringiensis strains including different plasmids or having different genes as studied by microcalorimetry

The heat out - put of metabolism of different Bacillus thuringiensis has be en studied by means of microcalorimetry. The experimental strains were a wi ld type (YBT - 1463) and engineering types (BMB160, BMB171, BMB - 304 - 171 - A, BMB - 304 - 171 - B). YBT - 1463 contains fourteen plasmids, BMB160 c ontains six plasmids but no insecticidal crystal protein. BMB171 have neith er plasmids nor insecticidal crystal protein gene. BMB - 304 - 171 - A and BMB - 304 - 171 - B each have a insecticidal crystal protein gene, one is t he gene of cry I Ac the other is cry I C. The experimental data show that t he heat out - put of metabolism of BMB171 is much more than that of YET - 1 463 and BMB160, and the metabolic heats of BMB - 304 - 171 - A and BMB - 30 4 - 171 - B are also less than that of BRIB171. These results indicate that the endogenuous plasmids have great effect on the metabolism of Bacillus t huringiensis. It is the same for the genes which are transformed into BMB17 1. Since there is no much difference between the genes of cry I Ac and cry I C, there is no dramatic change in thermokinetism. The first report of the thermokinetism in Bacillus thuringiensis is beneficial to the control of f ermention.