T.Monirah Alhammadi

  There are several ways to isolate microbes that produce antibiotics from the soil. Below are some methods used to isolate microbes produce antibiotics effective against some microbes

 Random Isolation in pure cultur crowded-plate Catrer and lockwood method Isolation of Antagonistic soil microorganisms

 soil isolation agar plate pure culture test each culture against Plant Pathogenic microbes inhibition zone # soil isolation agar plate pure culture test each culture against Plant Pathogenic microbes inhibition zone #Demonstrates the effectiveness of the microbe isolated from the soil against the microbe pathological #Demonstrates the effectiveness of the microbe isolated from the soil against the microbe pathological 1-Random Isolation in pure cultur

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 #fungus pathological pollination growth media Incubate plates # Then sprinkle dishes of soil dilution 1 \ 1000 to 1 \ approximately 0.6 cm Incubate plates Tset the plate inhibition zone 2- Catrer and lockwood method

 Catrer and lockwood method

  ] In this experiment, we will use the crowded- plate technigue for isolation of antibiotic- producing microorganisms from soil 3-crowded-plate

 # Soil suspensions(1:500 dilution of soil sample suspension) # cultures of E.coli, S.aureus, (P.aeruginosa # test tube # petri dishes #1-ml and 5-ml pipettes # bunsen burner # sterile water Materials

 1- label three test tubes 1,2and3. with apipette, add 5ml of tap water to eash tube. 2- shake the provided 1:500 soil sample thoroughly for 5 minutes to effect a uniform soil-water suspension. 3- using a 5-ml pipette, transfer 5 ml from the 1:500 dilution to tube 1 and mix. The final dilution is 1: using another pipette, transfer 5 ml from tube 1 to tube 2 and mix. The final dilution is 1: using another pipette, transfer 5 ml from tube 2 to tube 3 and mix. The final dilution is 1:400 0 Methods Methods :

 . 6-Using separate 1-ml pipettes, transfer 1 ml of the 1:1000, 1:2000  Dilutions to their appropriately labeled petri dilutions  agar ) trypticase soy ) 7- pour one tube of molten  8- incubate all plates in an inverted position for 2 to 4 days at 25C Methods:

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