Testing Total aerobic microorganisms

Principles: General tastes are counted by pouring and incubating under aerobic conditions at 300C / 72 ± 6 hours

1. Principles

General tastes are counted by pouring and incubating under aerobic conditions at 300C / 72 ± 6 hours

2. Environment and equipment

- Dilution: Saline Peptone Water (SPW)

- Culture medium: Platecount agar (PCA)

- Cabinet warm: 30 ± 10C

3. Process

- Dump: Transfer 1ml of sample solution after homogeneous or diluted in appropriate concentration to a sterile petri dish, one volume per plate. For 15 minutes, each plate of 15-20ml of PCA was cooled to 450C. Then mix the sample and culture medium.

- Incubation: The plates are overturned and incubated for 72 ± 6 hours at 30 ± 10C

4. Read the results

Read the results using either a regular eye or a magnifying glass with a magnification of 2 or 3 times to count the number of colonies growing on a petri dish (counting petri dishes with a colony number of 30 to 350) then multiplying dilution.