I found that for different media different sterilization SOP follows. Some passes the pure steam into the media after reaching temperature 95 or 90 through sparger and close the jacket steam and some not passes the steam inside the media and close the exhaust valve after reaching the temperature 95 and continue the sterilization with jacket steam.
which is best?
In my opinion, it is unnecessary...passing pure steam through the media during sterilization can add an additional quantities of water - after its condensation, to the medium and can alter the concentration of components of the medium, which could be critical to following fermentation process...
Thanks for your valuable answers.
Now I give you two types of SOPs of Media sterilization in fermenter for comparison analysis.
1. Media sterilization start with jacket steam and after reaching temperature 95 we close the exhaust valve and no steam passed through the top and sparger line into the media. Pressure increases and temperature maintained 121 by jacket steam only in auto mode.
2. Media sterilization start with jacket steam and after reaching temperature 95 we start giving pure steam through the sparger and jacket steam goes into auto mode. Exhaust valve open in this condition and pressure 1.2 bar maintain by control auto valve.
First process may be OK for the salts media. But for media containing peptone, yeast extract etc type pure steam must be passed though the media by sparger.
Steam is like a hot gas which comes into media and passed through it not condensate in it.
Jacket steam may be burn the media on the fermenter internal surface after reaching above 100 temperature but in second case it may not be possible.
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