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[Effect of K+ ions on Bac. polymyxa 153 growth and the biosynthesis of polymyxin B]
Abstract:
The growth of Bac. polymyxa, 153 producing polymyxin B did not change under the effect of various concentrations of potassium ions, while the antibiotic productivity of the cells significantly decreased. A great amount of polymyxin is excreted by the bacteria into the fermentation broth and a certain portion of the antibiotic remains in the cells. Under the experimental conditions the potassium salts slightly changed the pH value of the fermentation broth and probably did not affect polymyxin secretion from the cells into the fermentation broth.
Insights
Potassium ions did not affect Bacillus polymyxa growth but significantly reduced polymyxin B antibiotic production. Most of the antibiotic was excreted into the fermentation broth.
Area of Science:
- Microbiology
- Biochemistry
- Fermentation Technology
Background:
- Bacillus polymyxa is a bacterium known for producing the antibiotic polymyxin B.
- Polymyxin B is a crucial antibiotic used to treat infections caused by Gram-negative bacteria.
- Understanding factors influencing polymyxin B production is essential for optimizing antibiotic yields.
Purpose of the Study:
- To investigate the effect of varying potassium ion concentrations on the growth and polymyxin B production of Bacillus polymyxa.
- To determine how potassium ions influence the secretion and cellular retention of polymyxin B.
Main Methods:
- Culturing Bacillus polymyxa under different concentrations of potassium ions.
- Measuring bacterial growth through optical density or viable cell counts.
- Quantifying polymyxin B levels in both the fermentation broth and bacterial cells using appropriate assays.
Main Results:
- Bacterial growth of Bacillus polymyxa remained unaffected by different potassium ion concentrations.
- A significant decrease in polymyxin B antibiotic productivity was observed with increasing potassium ion concentrations.
- The majority of polymyxin B was found to be excreted into the fermentation broth, with a smaller portion remaining within the cells.
- Potassium salts caused minor alterations in the fermentation broth's pH, likely not impacting polymyxin secretion.
Conclusions:
- Potassium ions play a critical role in regulating polymyxin B biosynthesis or stability in Bacillus polymyxa.
- While bacterial growth is robust, antibiotic productivity is sensitive to potassium ion levels.
- Further research is needed to elucidate the precise mechanisms by which potassium ions inhibit polymyxin B production.