1. Dip a 5 mm diameter cork borer into alcohol. Set fire to the alcohol and let it burn away.
    Take care to hold the borer horizontally while doing this so that flames do not travel up the
    centre of the borer and burn your hand.

2. Hold the lid of a CMC agar plate slightly to one side and use the borer to cut a well in the
    agar. Remove the agar plug from the borer if necessary using a mounted needle.

3. Repeat steps 1 and 2 so that you have two wells in the agar.

4. Label each well on the base of the Petri dish. A suitable code would be: C (Cellulomonas);
    W (sterile water, a 'control').

5. Into the appropriate well place 0.2 ml of either microbial culture or sterile water, using a
    separate sterile syringe for each. Place the syringes, as they are used, in a beaker of
    disinfectant.

6. Incubate the plates for up to a week at 25-30^oC. Cellulomonas will produce clear zones up
    to 16 mm in diameter after 48 hours at 30^oC.
 

After incubation

1. Flood the plates with Congo red solution for 15 minutes, then de-stain with the salt solution for 10-15 minutes. Unstained areas indicate where the CMC has been broken down to b-1-4-glucans that contain seven or fewer glucose residues. The diameter of the clear zone can be measured to provide a quantitative comparison of cellulolytic activity.
 
 
 
 

Safety
 

Standard microbiological safety procedures, including aseptic techniques, must be observed by teachers, technicians and students when carrying out this work.