Tips on media preparation and how to dissolve starch? - (May/18/2014 )

tretol on Sun May 25 12:02:53 2014 said:

okay, then just glucose. I will incubate the inoculated plates in the absence of oxygen. This is the reason why I need sugars. If I do not provide a sugar source, how should the bacteria survive? They will not have components for fermentation. I am isolating bacteria from envorinment on different types of media (LB, Muller Hinton, Columbia Sheep blood) and for some bacteria I had good growth on my modiefied LB and only tiny colonies (or no growth) on the other media.

 

Additionally, I will test the oxygen requirements using thiglycolate broth. Thanks, I am always grateful for criticism.

I am not sure (as someone else also noted) why you are stating that you need sugars because they are (you think) anaerobic. Even anaerobic bacteria can use amino acids as carbon source.

LB is a good way to start, but not sure its the best..

I also wonder: how do you know that what you grow is the bug you are looking for?

Is your bacteria already isolated or ? I find it hard to understand what your goal is at the moment.

Hello,

okay, let me explain what I am doing:

I isolated bacteria from environmental samples and I am trying to characterize them. I do not think that the bacteria are anaerobic. I would like to test if they can survive under anerobic conditions.

I will get more environmental samples from different localities soon and I would like to isolate bacteria from these samples as well (all kinds of bacteria).

The samples are lipophilic and that's why I added Tween. But I am trying to further enrich LB. I also ordered meat extract but I think that yeast extract and meat extract is nearly the same (provide amino acids).

As mentioned before I also use other media.

The bacteria I am planning to isolate have never been isolated before. It might be that the samples I will receive are bacteria-free.

Hope this was clear

I see.

Its possible there are anaerobic bacteria in the samples too.. (I dont know where they come from, is it from the soil? water? ..)

You can use different media but its hard to culture most bacteria so dont expect to find a lot , especially new ones...

You also might try other ways to find novel bacteria.

Culturing is often a huge problem for new/unknown bacteria.
 

You also have to be very carefull not to end up with mixed cultures... so make sure you are indeed working with 1 specie when you characterise them.

tretol on Sun May 25 18:15:03 2014 said:

I also ordered meat extract but I think that yeast extract and meat

Roughly, yes. They are complex amino acid-rich extracts but their analytical composition is different. Check the Difco culture media manual (free on its web). They have the analysis of the hydrolysates and extracts nearly the end of the manual.