• KSBB Journal
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• v.6 no.1
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• pp.111-114
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• 1991

The effects of the precursor processing inhibitor, carbonylcyanide-chlorophenyl hydrazone(CCCP), are investigated on the production of soluble ${\beta}-lactamase$ the formation of the inclusion body when ${\beta}-lactamase$ is overproduced by induction with isopropyl thiogalactoside(IPTG). When cells are treated by CCCP, more soluble ${\beta}-lactamase$ is produced. In this case, no difference in the amount of inclusion body is observed.

• Journal of Life Science
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• v.8 no.6
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• pp.723-728
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• 1998

Bacillus subtilis J105, high resistant bacteria against $\beta$-lactam antibiotics, become higher resistant through induction of $\beta$--lactamase in the presence of $\beta$--lactam antibiotics. When there is no antibiotics in medium, the production of resistance-inductive $\beta$--lactamase reached its plateau 15 hours later. But when there is ampicillin (500$\mu\textrm{g}$/$m\ell$) in medium, the production of enzyme reached its plateau 25 hours later since cultivating bacteria, whereas it is found that enzyme 2,900 units/$m\ell$ about 20 times as much as compared with not-presence of antibiotics was actived. In addition, as the result of MIC comparing applying ampicillin-treated and non-treated strain MIC of ampicillin-treated strain is about 2~27 times higher. It is considered that this strain induce $\beta$--lactamase production by ampicil-lin-treatment, then increasing it resistance. It is found that this resistant strain induce $\beta$--lactamase production against cephalosporin antibiotics as well as peni-cillin. As the result of examining the time of adding antibiotics for each phase of growth, it is concluded that logarith-mic phase is the most effective. As the aboves, it is suggested that this strain is a peculia strain that its resistance is induced high by various $\beta$--lactam antibiotics.

• Journal of Microbiology and Biotechnology
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• v.2 no.1
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• pp.26-34
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• 1992

The effect of induction temperature on fermentation parameters has been investigated extensively using Escherichia coli M5248[pNKM21], a producer of recombinant human interleukin-2 (rhIL-2). In this recombinant microorganism, the gene expression of rhIL-2 is regulated by the cI857 repressor and $P_L$ promoter system. The recombinant fermentation parameters studied in this work include the cell growth, protein synthesis, cell viability, plasmid stability, $\beta$-lactamase activity, and rhIL-2 productivity. Interrelationships of such fermentation parameters have been analyzed through a quantitative assessment of the experimental data set obtained at eight different culture conditions. While the expression of rhIL-2 gene was repressed at culture temperatures below $34^\circ{C}$ with little effect on other fermentation parameters, under the conditions of rhIL-2 production $>(36~44^\circ{C})$ the cell growth, plasmid stability, and $\beta$-lactamase activity were, as induction temperature was increased, more profoundly reduced. Although the rhIL-2 content in the insoluble protein fraction was maximum at $40^\circ{C}$, total rhIL-2 production in the culture volume was found to be highest at the induction temperature of $36^\circ{C}$. This was in contrast to the previously known optimum induction temperature of the P$_{L}$ promoter system $>(40~42^\circ{C})$.Explanations for such a discrepancy have been proposed based on a product formation kinetics, and their implications have been discussed in detail.l.