Sensitivity to Hydrogen Peroxide of Growth and Hyaluronic Acid Production by Streptococcus zooepidemicus ATCC 39920
✍ Scribed by Mashitah, M.D. ;Masitah, H. ;Ramachandran, K.B.
- Publisher
- Curtin University of Technology
- Year
- 2008
- Tongue
- English
- Weight
- 553 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0969-1855
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✦ Synopsis
Abstract
The sensitivity to hydrogen peroxide (H~2~O~2~) of growth and hyaluronic acid (HA) production by Streptococcus zooepidemicus ATCC 39920 was studied under various conditions. In sheep blood agar‐plates, no detectable zone was observed even when the concentration of H~2~O~2~ was increased to 0.15 mM. With brain heart infusion‐agar and chemically defined medium‐agar plates, a profound zone was detected at 0.015 mM concentration of H~2~O~2~. To determine the minimal inhibitory concentration (MIC) of the strain in culture broth, various concentrations of H~2~O~2~ (0‐200 mM) were maintained in the medium prior to fermentation. The result showed that for higher concentrations of H~2~O~2~ in the medium, the greater was the inhibition. Streptococcus is catalase‐negative and known to produce H~2~O~2~ which may affect growth, HA production and glucose utilization. In order to determine at which growth phase H~2~O~2~ had the maximum inhibitory activity, a batch fermentation of S. zooepidemicus was conducted in shake flask culture. It was found that H~2~O~2~ production took place during the growth phase, and HA production started after the growth had reach late exponential phase when H~2~O~2~ in the culture media was depleted. This indicates that H~2~O~2~ produced by the cells did not affect cell growth but influenced HA production.