How to separate, purify and cultivate microorganisms in soil?

1. Soil sample collection: take10g10cm deep soil for later use. ?

2. Preparation of soil diluent: Weigh 1g soil, put it into a triangular bottle filled with 99mL sterile water, and shake it evenly to obtain the diluted 10-2 soil suspension. Then ten-fold gradient dilution is carried out to prepare in turn? 10-3、 10-4、 10-5

、 10-6? 、 10-7? Dilution of soil diluent. ? 3. Preparation of culture medium plate: Prepare 100ml beef sauce peptone agar medium, Martin's medium and Gauss I medium according to the culture medium formula. After sterilization, pour 3 plates respectively. (10) Before sterilization, 10% phenol was added dropwise to Gauss I medium; Add 2ml sodium deoxycholate (2%) and 0.4ml? 10000 unit/ml streptomycin)?

4. Inoculation: Suck the 0. 1ml soil diluent with the corresponding concentration with a sterile straw, inoculate it on a flat plate with sterile operation technology, and evenly coat it. Bacteria are selected from 10-4, 10-5 and 10-6? Three diluents were inoculated in beef sauce peptone agar medium, and actinomycetes and molds were screened as 10-2? 、 10-3、 10-4? Three diluents were inoculated in Gao's I medium and Martin's medium respectively. (one dilution and one plate)?

5. Culture: bacteria cultured at 37℃ 1 ~ 2d, actinomycetes cultured at 30℃ for 2 ~ 3d, and mold cultured at 30℃ for 3 ~ 5d? , observe. ?

6. Counting: count with the colony counting method of diluted water sample detection plate, and report the total number of bacteria /(cfu mL- 1)?

7. Purification: Select typical colonies and inoculate them on corresponding plates. The culture conditions are the same as above, and the culture is purified.