How long with bacteria in the original tube of BC03?

[Jeff]

Once we open and use inculating loops to transfer some bacteria out of the original tubes of BC03, how long does the bacteria in the original tube last?  We transfer some of that into saline tubes in one of our labs then put that tube in the refrig.  If it is over a month since I opened the original tube of BC03, is it better to go back into that tube or use the bacteria we put into the saline tubes?  Please describe when the bacteria in BC03 is no longer fully "alive" and how and when it degrades.

Thank you,

Jeff

[Jeff]

From lab book page 235 - which leads to the question - is it better to keep the original cultures BC03 in the original tube, or do we need to do this reculturing into a saline tube?

"Because we don’t want to have to purchase the mixed culture

more than once, we’ll also inoculate one broth tube and two

normal saline tubes with the purchased culture and store

the broth tube in the refrigerator. This procedure, called reculturing,

allows us to extend the useful life of the original

culture."

[Robert Bruce Thompson]

Assuming you store the BC03 culture tube tightly capped at room
temperature in the dark, it should remain viable indefinitely. The BC03
culture is actually a very dilute suspension of the three bacteria
species in phosphate-buffered saline, which puts them essentially in
stasis. The oldest BC03 culture that I've recultured was about six years
old, and it recultured without any problems. I'd go ahead and reculture
from the original BC03 tube.

[Robert Bruce Thompson]

I would just keep the original BC03 culture for ongoing use. We
periodically reculture to make sure that the PBS culture remains viable,
but that's not something you should need to do routinely if you have the
BC03 culture available. You can reculture if you start to run low on the
original culture.