Sciencemadness Discussion Board

"Bacteriological Peptone"

Organikum - 27-4-2006 at 08:56

A biosynthesis calls for "Bacteriological Peptone", I found the original supplier named in the text oxoid, they deliver also where I live but it is pretty far away from where I live and I believe it will be comparable expensive (have inquired about costs but no answer by now).

With what might this be substituted and what is this exactly in difference to other peptones of trade, yeast extract and meat extract?

regards
/ORG

chemoleo - 27-4-2006 at 16:43

I believe bacterial peptone is a proteolytic extract of bacterial cell mass.... so a vast range of peptides, amino acids, trace elements, vitamins, etc. Peptone presumably as in a pepsin (protease) digest of bacterial protein extracts. I am sure a yeast peptone/extract would be good as well, maybe not optimal (naturally, since the composition is that of yeast, and not bacteria) but still good enough to grow things on.

Further, meat extracts are going to be even less good... but again I should think they can be used with some bacteria, i.e. some that are happy with almost any medium. Plus, let's not forget that i.e. Ecoli are normally grown in a mix of yeast and bacterial peptone. If you want I can look up more details on the detailed identity of these things, but you won't hear of the results before next week.... (going hiking over the WE...yay!)

Do you have an autoclave, agar, and so on, for growth?

[Edited on 28-4-2006 by chemoleo]

wa gwan - 28-4-2006 at 12:55

Quote:
Originally posted by chemoleo
I believe bacterial peptone is a proteolytic extract of bacterial cell mass.


The protein source is animal protein rather than bacterial cell mass. "Bacteriological" refers to it being a multi-purpose peptone, "mycological" for fungal cultures and so on.

Autolysed yeast extract is like a crude peptone of a kind and will probably work quite well.
Quote:
Peptone

Peptone is a spray dried powder, manufactured by a controlled enzymatic hydrolysis of animal tissue. The most commonly used enzymes are pepsin, papain and pancreatin. The latter containing trypsin.

Pepsin will cut the peptide chain anywhere there is a phenylalanine or leucine bond.

Papain cuts in the peptide chain adjacent to arginine, lysine, phenylalanine and glycine. Pancreatin has its action at arginine, lysine, tyrosine, tryptophan, phenylalanine and leucine bonds.

The tissues are hydrolysed to produce straw coloured peptones which are highly nutritious and clearly soluble in water. Peptones contain a mix of peptides, free amino acids and growth factors.

Due to the low sodium chloride concentration ForMedium Pepton is well suited for cultivation of yeast cells.


Taken from Formedium's product data. EU shipping €4.50

And since I know how you like a good steak Org, A 1 hr papain (paw paw) or bromelain (pineapple) marinade will tenderize a steak to perfection. Don't let it soak too long though or you'll have peptone soup. :)

[Edited on 28-4-2006 by wa gwan]

nitro-genes - 29-4-2006 at 14:59

Luckily for us, the peptide bond is quit resistant agains hydrolyzation.. Amazing how well enzymes have evolved to become almost "perfect" in a thermodynamical way. For some, like TIM for example, the reaction conversion rate is in the picosecond range and the substrate diffusion rate becomes the reaction rate limiting step...:o

Anyway, I mentioned the nutritional yeast pills before as a possible peptone and yeast extract substitute before. They are made of pressed and dried cells of S. cerevisiae siccum and are sold even in supermarkets as a vitamin B suplement. Because it is for direct oral intake, I think it is possibly well sterillised also...

Organikum - 1-6-2006 at 01:17

Got it now:




:D

/ORG

Xque - 1-6-2006 at 01:21

Great, congratulations :D Don't want to pry in your business, but may I ask what biosynthesis you need it for?

Chucklz - 1-6-2006 at 12:41

Keep the peptone tightly sealed, in a dry area, perhaps even with some parafilm to seal the lid even further. This will keep for years beyond its expiration date with no ill effect, provided it stays dry.

Your bottle has "IVD" on it, that is its suitable for InVitro Diagnostics. Try and buy the "non-IVD" stuff, as it is often much cheaper, and just as good for almost all purposes.

Organikum - 1-6-2006 at 13:32

Actually I bought it for the purpose of opening it. Because I want to do something with it. But how to keep the opened bottle sterile for some weeks? H2O2?

curious
/ORG

chemoleo - 1-6-2006 at 13:55

Quote:
Actually I bought it for the purpose of opening it.

Tsts orgi you sound like you have the period :D:D

Anyway... if you use it for bacterial growth you will have to sterilise/autoclave, unless you have the means of weighing, and dissolving in sterile conditions. Even if you have those means, autoclaving is preferred.
Other than that I have never seen peptone/tryptone going off, as long as it's dry. It should last years .. which it certainly does in a 10 kg bucket we have here.

Organikum - 1-6-2006 at 14:09

Thanks. I am not "orgi" schatzi, but thanks.

/ORG