Proteinguy1995
Member
- Joined
- Nov 19, 2018
- Messages
- 8
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Hey guys,
I am a graduate student in biochemistry and do a lot of protein expression/purification using E.Coli, and P.Pastoris (similar strain of yeast to S.Cerevisiae). Generally I use ampicillin in my yeast starters to limit bacterial growth in the initial stages (yeast strain has AMP resistance gene) as the doubling time for P.pastoris is much slower (90 min) than general bacteria (20-30min) and can easily be overwhelmed in the growth media leading to a lower yield of protein.
Anyways, I had some 100mg doxycycline tablets at home that I was using to treat acne, and thought it would be a good idea to add a little bit to the wort. Doxycycline is much more specific to bacteria than it is to fungus as it targets the 30S subunit of the ribosome (ok, enough science).
One of the degredation products of tetracyclines (at low pH, generally <2) is anhydro-4-epitetracycline, which can lead to falconi syndrome (kidney damage). However, in the case of doxycycline, the absence of a hydroxyl group in C-6 prevents the formation of the nephrotoxic compound.
I added about 5mg/L of doxycycline to my wort just when i pitched my yeast. It was a 3 gallon batch, so about 60mg was added to the whole batch(I was taking 100mg/day for months). Its also interesting to note that ancient nubians used to brew tetracycline beer!
Anyways, I am worried for any possible metabolic products that could have been produced to cause adverse effects. However, it was added in such low concentration that about 1-2mg would make it to 1 beer anyways.
What do you guys think? have you ever used antibiotics in your wort to stall bacterial growth? Do large scale breweries use antibiotics?
Sorry for all the nonsense,
Cheers.
I am a graduate student in biochemistry and do a lot of protein expression/purification using E.Coli, and P.Pastoris (similar strain of yeast to S.Cerevisiae). Generally I use ampicillin in my yeast starters to limit bacterial growth in the initial stages (yeast strain has AMP resistance gene) as the doubling time for P.pastoris is much slower (90 min) than general bacteria (20-30min) and can easily be overwhelmed in the growth media leading to a lower yield of protein.
Anyways, I had some 100mg doxycycline tablets at home that I was using to treat acne, and thought it would be a good idea to add a little bit to the wort. Doxycycline is much more specific to bacteria than it is to fungus as it targets the 30S subunit of the ribosome (ok, enough science).
One of the degredation products of tetracyclines (at low pH, generally <2) is anhydro-4-epitetracycline, which can lead to falconi syndrome (kidney damage). However, in the case of doxycycline, the absence of a hydroxyl group in C-6 prevents the formation of the nephrotoxic compound.
I added about 5mg/L of doxycycline to my wort just when i pitched my yeast. It was a 3 gallon batch, so about 60mg was added to the whole batch(I was taking 100mg/day for months). Its also interesting to note that ancient nubians used to brew tetracycline beer!
Anyways, I am worried for any possible metabolic products that could have been produced to cause adverse effects. However, it was added in such low concentration that about 1-2mg would make it to 1 beer anyways.
What do you guys think? have you ever used antibiotics in your wort to stall bacterial growth? Do large scale breweries use antibiotics?
Sorry for all the nonsense,
Cheers.