About Purified Water Microbiological Analysis

Hey guys, im working in a microbiology lab. and we are going to start analysis of purified water ;

I have multiple questions ;

  • After the filtration of sample, is it necessary to wash the membrane with peptone water?

  • Which method is the better for detection of P. aeruginosa in purified water?
    a- Filter 100ml of purified water, add it to the TSB media incubate for 1 day, take passage to Cetrimide agar
    b- Add 10ml of purified water directly to 100ml of TSB media , incubate for 1 day, take passage to Cetrimide agar

Thanks for your helps…

@Gokay it is important to wash the membrane with peptone water to get the proper growth of microbes on membrane filter.
Apply the method for P. aeruginosa as per the pharmacopoeia you are following as USP, BP, EP etc.

Dear Ankur, we are using dehidrated buffered sodium chloride peptone water, is it essential to perform any test (like growth promotion like mediums) whenever we prepare it?

I know we have to perform growth promotion test on every new batch of mediums but i couldnt find any source about peptone water.

Thanks for your replies.

Yes you have to test peptone water too for growth promotion before you use it.

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Dear All,

Why generally two hours is specified for analysis of water?
Also why 0.2 % sodium thyosulphate added for portable water collection and analysis?