Growing yeast starters in the lab

What????? I would say you are the research expert, so do it and you report back your findings.

 

Yeast can suffer from cell shear stress from mechanical action, so maybe the centrifuge might be overkill? Just chill it or pitch the whole thing at high krausen

Or run a load of tests and report back

 

ask @Biobrewer

 

Certainly shaking your culture with good temperature control is good. If I centrifuged it I would use a low speed and work it more to a slurry than a pellet. You may want to be careful though. I worked in industry and using anything in the lab that would be used for food was a big nono and could have gotten us fired. Academic labs are more lax, but I would be careful.

 

I used to do that all the time, works fine. I resuspend in sterile phosphate buffered saline.

Actually I usually grew the starter at home and took it to the lab to spin down. The shaker incubator will work fine.

You can do a cell count after resuspending as well so you really know your pitching rate.
Good luck!

Edit: I used to take my wyeast activator pack and split it into 4 aliquots, equal to a wyeast propagator.

 

one of my drinking buddies is a bio medical professor at Cornell. when i discussed building a kit bash stir plate he laughed and related that his lab has dozens, all with temp control. i'll ask him his specific advice next time.

or, you know, ask your professor. i would think that a stir plate that can maintain about 80F is probably all you really need. no need to make this more complex than it needs to be.
Cheers.

 

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I have to say I was taken aback by the shear stress idea. If you think about it, a stir plate might (during 24-ish hours) cause more shear stress than a minute or two in a centrifuge. All I can offer is that yeast on a stir-plate makes more/faster (healthy) yeast than yeast not on a stir plate. So I'm thinking a centrifuge is probably not a yeast killer. But man, I really don't know.

 

The shear stress from a stirplate (or a spinner flasgk for immunobiologist) is not enough to kill them. Yeast are notoriously one of the more difficult cells to rupture due to their protoglycan component of their cell wall.

RPM and the resulting g force are different for different centrifuges. Been a long time but I think I used 1000x for 15 min.

 

A centrifuge is not a yeast killer, that is a ******ed idea. Yeast cells ate not nearly as fragile as mammalian cells such as CHO or HEK293 celks. During my Ph.D. I'd routinely culture mammalian, yeast or bacterial cells for protein expression, centrifuging below 4,000 x g, will do nothing to the cells. 30,000 x g won't do anything to bacteria or yeast, mammalian cells,not so sure (I''ve only centrifigued them in a vaccum ultra centrifuge at 100,000 x g for membrane preparations after lysis).

 

I read bad consequences to mean death. I'm sorry my interpretation has upset you. If you are worried about responses to a nebulous statement that assume things then do what you did in your response and explicitly state things;

If it were me, and I was asking this question, and my university library had solid literature access, I'd try and do a literature search instead. It is sometimes surprisong regarding the breadth of experimental data that exists in the brewing literature, including negative results. As another option, try contacting wyeast or white labs. They obviously have a ton of experience in propagation, and might be able and willing to lend a hand as long as it is not proprietary information, which I really doubt the answer to this question would be.