Antibiotics

The production of antibiotic is the earliest and most important application of our liquid liquid centrifugal extractor. Tiei Extraction^® centrifuges are widely used for extracting or purifying the antibiotics from fermentation broth. We can effectively separate solutions containing antibiotics by centrifugal force generated by centrifuges, providing a foundation for further purification.

The extraction process of antibiotic can be : 1. multi-stage countercurrent extraction; 2. multi-stage cross flow extraction . In multi-stage countercurrent extraction, the feed liquid is added to the first stage and gradually moves downwards, while the extractant is added to the last stage and gradually moves forward. The direction of feed liquid movement is opposite to the direction of extractant movement, so it is called countercurrent extraction . In cross flow extraction, only the extractant is added in the last stage, so compared to cross flow extraction, the consumption of extractant is lower, resulting in a higher average concentration of the extract solution.

The steps for extracting penicillin from fermentation broth by multi-stage countercurrent extraction with our three- stages cascade of centrifuges:

Step 1- Extraction: Use H2SO4 to adjust the PH of the filtered fermentation broth, add butyl acetate in a certain proportion and an appropriate amount of demulsifier , then countercurrent extraction at low temperature (like 5 degrees).

Step 2 - Washing : Butyl acetate which containing the penicillin go to the centrifuges for washing out the water soluble pigments and impurities.

Step 3 - Back extraction : use NaHCO3 as back extration agent, add 1.5% NaHCO3 solution in the loaded Butyl acetate to extract the target products back.

Precautions for using a centrifuge to extract penicillin:

• Prepare a certain concentration of demulsifier to eliminate emulsification during the extraction process;
• Prepare a certain concentration of dilute sulfuric acid to adjust pH;
• Due to the instability of penicillin aqueous solution, three principles should be followed during operation: short time, low temperature, and moderate pH;
• To reduce the degradation of penicillin, the entire extraction process should be carried out at low temperatures (below 10C) .

Applications