Oscillatory behavior of population density in continuous culture of genetic‐engineered Bacillus stearothermophilus

An oscillatory behavior in population density was observed when a transformant of Bacillus stearothermophilus carrying a rocombinant plasmid pZAM26 was cultivated continuously in a well‐stirred reactor vessel at a fixed dilution rato. Among the transformant cells that were subjected to the continuous culture, the fraction of cells harboring p2AM26 was found to be as high as 0.98–1.00 despite the emergence of the oscillation. Cells whose plasmids underwent rearrangement of DMA in terms of structural change could not be found throughout. With reference to this observation, the dynamics of the genetic‐engineered bacterium was analyzed within the category of both the linearized stability principle and the bifurcation theory. It was concluded that Hopf bifurcation was most probable to account for the experimental oscillation.

[1]  S Pavlou,et al.  Dynamics of a chemostat in which one microbial population feeds on another , 1985, Biotechnology and bioengineering.

[2]  S. Aiba,et al.  Effects of temperature on plasmid stability and penicillinase productivity of a transformant of Bacillus stearothermophilus. , 1984, Annals of the New York Academy of Sciences.

[3]  S. Aiba,et al.  Effects of temperature and dilution rate on the copy number of recombinant plasmid in continuous culture of Bacillus stearothermophilus (pLP11) , 1985, Biotechnology and bioengineering.

[4]  P. Gustafsson,et al.  The use of a partition locus to increase stability of tryptophan-operon-bearing plasmids in Escherichia coli. , 1983, Gene.

[5]  S. Aiba,et al.  Production of alpha-amylase in transformant of bacillus stearothermophilus-improvement of recombinant plasmid that can be used at higher temperatures. , 1987, Biotechnology and bioengineering.

[6]  T. Imanaka,et al.  Instability of plasmid-harboring strain of E. coli in continuous culture. , 1982, Biotechnology and bioengineering.

[7]  K. Kadam,et al.  Investigation of plasmid instability in amylase‐producing B. subtilis using continuous culture , 1987, Biotechnology and bioengineering.

[8]  T. Imanaka,et al.  Temperature-dependent plasmid integration into and excision from the chromosome of Bacillus stearothermophilus. , 1986, Journal of general microbiology.

[9]  T. Imanaka,et al.  Transformation of Bacillus stearothermophilus with plasmid DNA and characterization of shuttle vector plasmids between Bacillus stearothermophilus and Bacillus subtilis , 1982, Journal of bacteriology.

[10]  J E Bailey,et al.  A kinetic model for product formation in unstable recombinant populations , 1985, Biotechnology and bioengineering.

[11]  T. Imanaka,et al.  Cloning and Expression of Thermostable α-Amylase Gene from Bacillus stearothermophilus in Bacillus stearothermophilus and Bacillus subtilis , 1983 .

[12]  S. Aiba,et al.  ENHANCED PRODUCTION OF α-AMYLASE AND PLASMID STABILITY IN BATCH AND/OR CONTINUOUS CULTURES OF BACILLUS STEAROTHERMOPHILUS (pAT9) , 1986 .