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Published on: January 7, 2019
Xanthan production in bubble column and air-lift reactors
I S Suh1, A Schumpe, W D Deckwer
1GBF-National Research Center for Biotechnology, Biochemical Engineering Division, Braunschweig, Germany.
Biotechnology and Bioengineering
|January 5, 1992
Summary
Xanthan production by Xanthomonas campestris is limited by oxygen availability. Fermentation models accurately predict polysaccharide production in bubble columns but not air-lift fermentors due to oxygen supply issues.
Area of Science:
- Biotechnology
- Microbial Fermentation
- Biochemical Engineering
Background:
- Exocellular microbial polysaccharides like xanthan are valuable bioproducts.
- Efficient fermentation processes are crucial for optimizing xanthan yield.
- Oxygen transfer is a critical factor in microbial fermentation performance.
Purpose of the Study:
- To compare xanthan production in bubble column and air-lift fermentors.
- To evaluate the influence of oxygen transfer rates on xanthan production.
- To validate fermentation models for xanthan synthesis.
Main Methods:
- Xanthan production using Xanthomonas campestris in synthetic and complex media.
- Utilized bubble column (0.05 m3) and air-lift (1.2 m3) fermentors.
- Applied oxygen transfer rate correlations and batch fermentation models.
Main Results:
- Xanthan production rate correlated linearly with oxygen transfer rate after initial depletion.
- Bubble column fermentation performance was well-described by existing models.
- Air-lift fermentor showed reduced xanthan production and yield, attributed to inadequate downcomer oxygen supply.
Conclusions:
- Oxygen transfer rate is a key limiting factor for xanthan production.
- Bubble columns offer predictable performance for xanthan fermentation.
- Air-lift fermentor design requires optimization for improved oxygen supply to enhance xanthan yields.
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