Problem in bacterial cell culture - (Jan/28/2014 )
Dear all,
I would like to seek for your opinion. What's the condition will causing the bacterial strain to become weaker? I have 2 probiotic bacterial strains which will growth actively within 18 hours in milk, however now the strain seems like become weaker and grow very slow even I incubate for 48 hours. Did anyone know the reason?
Thank you.
Maybe the strains aren't what you think they are (maybe have become contaminated with something else)? It could also be that there are antibiotic residues in the milk, or something has been altered in the milk composition with time of year (if pasture fed animals). It could also be that there is some lab based evolution, or you have subconsciously selected for a slow growing strain, or haven't stored them properly so they take a long time to recover.
Yoghurt cultures, for example, are required to contain at least three different species of bacteria. Perhaps your probiotic cultures are also mixed cultures. If they are, then continuous culture could easily lead to overgrowth of one of the constituent species.
Dear Thelymitra pulchella，
May I know is there any way to recover back the bacteria to make it become active? Thanks
Dear Veteran,
I am using 6 bacterial strains, but culture it separately. It was strange and I find out that, the same bacterial strain (A), using the same technique, same material to culture into same volume of milk, but it growth very well in one bottle and totally no growth at all in another bottle.
Celz on Sun Feb 2 00:42:45 2014 said:
Dear Thelymitra pulchella，
May I know is there any way to recover back the bacteria to make it become active? Thanks
You can select for fast growing strains by just doing growth curves on lots of different isolates, and repeatedly choosing only those that grow faster than others. For incorrect storage - you should get the bacteria growing actively again and then make more stocks under appropriate conditions for your bacteria.
bob1 on Sun Feb 2 01:24:16 2014 said:
Celz on Sun Feb 2 00:42:45 2014 said:
Dear Thelymitra pulchella，
May I know is there any way to recover back the bacteria to make it become active? Thanks
You can select for fast growing strains by just doing growth curves on lots of different isolates, and repeatedly choosing only those that grow faster than others. For incorrect storage - you should get the bacteria growing actively again and then make more stocks under appropriate conditions for your bacteria.
Do you think the bacteria can be activate back if I culture it onto the agar plate and isolate the single colony? Thank you.
Celz on Mon Feb 3 00:41:45 2014 said:
bob1 on Sun Feb 2 01:24:16 2014 said:
Celz on Sun Feb 2 00:42:45 2014 said:
Dear Thelymitra pulchella，
May I know is there any way to recover back the bacteria to make it become active? Thanks
You can select for fast growing strains by just doing growth curves on lots of different isolates, and repeatedly choosing only those that grow faster than others. For incorrect storage - you should get the bacteria growing actively again and then make more stocks under appropriate conditions for your bacteria.
Do you think the bacteria can be activate back if I culture it onto the agar plate and isolate the single colony? Thank you.
Its not so much about "activating" them back, its more about selecting the right isolate again...
Some will be fast growers, others slow growers, its just up to you to get that fast growing one back...
(and yes, some might indeed be slow growers, but due to a mutation become fast growers..)
pito on Tue Feb 4 09:28:14 2014 said:
Celz on Mon Feb 3 00:41:45 2014 said:
bob1 on Sun Feb 2 01:24:16 2014 said:
Celz on Sun Feb 2 00:42:45 2014 said:
Dear Thelymitra pulchella，
May I know is there any way to recover back the bacteria to make it become active? Thanks
You can select for fast growing strains by just doing growth curves on lots of different isolates, and repeatedly choosing only those that grow faster than others. For incorrect storage - you should get the bacteria growing actively again and then make more stocks under appropriate conditions for your bacteria.
Do you think the bacteria can be activate back if I culture it onto the agar plate and isolate the single colony? Thank you.
Its not so much about "activating" them back, its more about selecting the right isolate again...
Some will be fast growers, others slow growers, its just up to you to get that fast growing one back...
(and yes, some might indeed be slow growers, but due to a mutation become fast growers..)
Do you think if I streak it on an appropriate agar plate, incubate and isolate the single colony will be a good way to get back the active colony among all the weakest one? Thank you.
No- growth on agar is very difficult to give an indication of the growth rate - you need to pick single colonies and screen them for growth rate in liquid culture.