Microbiological analysis of water (1)

Microorganisms are tiny organisms that cannot be seen by the naked eye.

1.

(1) Detection of the total number of bacteria

Because each type of bacteria has its own certain physiological characteristics, different nutritional conditions and other victory conditions are used to meet its requirements during cultivation

(2) Detection of total coliforms.

(3) Significance of detection of fecal coliforms

2.

The total number of bacteria refers to the total number of bacterial colonies grown in 1ml water sample in nutrient agar medium at 37°C for 24 hours

(1) The scope of application

1) This method is suitable for determining the total number of bacteria in drinking water and source water

2) The increase in the total number of bacteria measured indicates that the water is polluted by domestic waste, but it cannot explain the source of the pollution

(2) Instruments

1) High pressure steam sterilizer

2) Dry heat sterilization box

3) Incubator

4) Refrigerator

5) Magnifying glass
.

6) Test tubes, plates (diameter 9cm), graduated straws, etc.
, placed in a dry heat sterilization box at 160°C for 2 hours
.

(3) Medium
.

1) Ingredients
.

a.
Peptone , 10g
.

b.
Beef extract, 3g
.

c.
Sodium chloride , 5g
.

d.
Agar, 10～20g
.

e.
Distilled water, 100ml
.

2) Manufacturing method
.

After mixing the above ingredients, heat to dissolve, adjust the pH to 7.
4 to 7.
6, filter, divide into glass containers, sterilize at 121°C for 20 minutes, and store in a dark place for later use
.

Related Links: Application of Spectrophotometry in Water Quality Analysis (2)