agar melting

[kpac]

Hi Just wondering,

I made up some nutrient agar for a bacteria prac not that long ago and had some left over. I put the left over agar bottle in the fridge. Obviously it has hardened. I was wondering do I use a water bath to melt this agar then pour it straight into the plates OR do I need to melt it then re autoclave it then pour it?

 

Thanks kel

[KipIngram]

At some point you'll need to re-sterilize it. I've done a smidge of yeast culturing for beer brewing. Refrigerators tremendously slow bacterial growth, but they don't fully eliminate them.

[kpac]

OK that's what I thought i'll pull it out of the fridge melt it and the re autoclave it, then pour.

Its just to take swabs of a hospitality kitchen,they wanted agar plates but I have nutrient agar does it really matter if I don't use just plain agar and use nutrient agar? The results should still be the same no?

[KipIngram]

What are you going to do with it after swabbing it? If you leave it warm stuff will grow in the nutrient agar.

 

There are a few commercial beers that have live yeast in them (I think Sierra Nevada is one). You can do stuff like this to culture them up to where you can make a starter. So I always wanted something to grow. Usually I'd wind up with some bacteria too, but they'd be in separate colonies. You can look with a microscope to tell which colonies are yeast, and then scrape that up and put it in a small starter, very well sterilized, and work your way up.

 

I haven't brewed in years - I really should get back to that.

[kpac]

That's ok I was just going to swab the hospitality kitchen and incubate plates after, all good I will just make new agar and just throw out the previous nutrient agar bottle. Thanks for youre help

[KipIngram]

You bet - good luck!