Ask The Brewmasters

We have been using cycloheximide in our lab media to suppress wild yeast growth in plating but are now considering using nystatin instead.  Anyone out there using nystatin?  Any issues experienced with its use?

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Geoff Deman
Head Brewer, Free State Brewing
President, MBAA District Great Plains
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Hey Geoff!

  We switched over from cyclo to nystatin last year for our anaerobic broth media due to the amount of handling needed to clean the tubes and the risk to our techs. We still use cyclo for our plate media! To determine the proper concentration, we ran an experiment of anaerobic broth dosed with different concentrations of nystatin. We then inoculated these tubes with yeast, lacto and pedio and waited for incubated results to ensure we were killing the yeast but not the bacteria. I recommend running something similar if you can since the nystatin and media type are probably different than ours. There is a method for this on ASBC as well. Let me know if you have any more questions but we love the nystatin since it is so much safer! 

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Shaye Holdaway
Chemist; Technologist; Microbiologist; Lab Assistant; Technicians
Prost Brewing Company
(602) 499-1248
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Hi Geoff,

We started using nystatin a long time ago due to the risks and hazards that cyclohexamide has with usage handling, disposal and health concerns it can cause for lab staff if not properly ventilated during use.  We had really good luck with the Nystatin.  I know our lab staff at the time authored a paper about it on the MBAA or with the ASBC,  I'll see if I can find the paper in our old computer files but otherwise you might be able to find it online.    I don't remember what our usage was but it worked really well.  I would definitely suggest using it. 

 Curtis Holmes

Alaskan Brewing

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Cheers,
Curtis Holmes
Alaskan Brewing Co
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