{"id":552,"date":"2015-05-08T13:53:00","date_gmt":"2015-05-08T13:53:00","guid":{"rendered":"http:\/\/suigenerisbrewing.com\/index.php\/2015\/05\/08\/purifying-yeast-from-infected-cultures-part-2\/"},"modified":"2017-09-15T18:02:53","modified_gmt":"2017-09-15T18:02:53","slug":"purifying-yeast-from-infected-cultures-part-2","status":"publish","type":"post","link":"https:\/\/suigenerisbrewing.com\/index.php\/2015\/05\/08\/purifying-yeast-from-infected-cultures-part-2\/","title":{"rendered":"Purifying Yeast from Infected Cultures – Part 2"},"content":{"rendered":"

A couple of days ago I put up a post describing the first step in purifying a contaminated yeast culture<\/a>. In that post I described a simple method (requiring some specialized reagents) which allows a contaminated sample to be depleted of a contaminating bacteria, and also to provide semi-pure cultures of Saccharomyces<\/i> and Brettanomyces<\/i>. But as far as that method goes, it doesn’t ensure complete depletion of the contaminants, nor pure cultures of Sacc <\/i>or Brett<\/i>.<\/p>\n

So how do we get a totally pure culture? The answer…streak plating<\/a>, followed by a quick screen to ensure purity.<\/p>\n

Details below the fold.
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Streaking the yeast<\/h3>\n
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Making streak plates is a topic I’ve covered before, in the below video. The idea is simple – you use a plate to “dilute out” your yeast sample until you have well separated colonies, each of which arises from a single cell. This now allows you to isolate a pure strain of yeast. You can add antibiotics and other selective agents to the plates, but I actually prefer not to add these compounds – this gives you a chance to confirm that the depletion step worked properly.<\/p>\n<\/div>\n