I have been doing an analysis called cellulolytic activity (Smith and Hughes, 2001) in order to see if there is any fungal activity in the soil. The method basically involves the use of filter paper as a source of cellulose. I placed the filter paper in a petri-dish and put soil beneath and on top of the filter paper, but separated the soil and filter paper with gauze in order to avoid sticking of the soil on the filter paper. The petri-dish is incubated at 25 degrees for 7 days. The filter paper is weighed before incubation and after the 7 days to see if there has been any degradation, but all the samples that I done so far do not show any degradation. I am not sure what type of cellulose is in the filter paper, so I am wondering if it is possible that there is a form of cellulose that fungi are unable to degrade? Or is there any other explanation as to why my filter papers aren't degrading?
I did the same technique and i got a wonderful results, first you should note the moisture content of your Petri-dishes also you should wait for at least 21 days.
Cellulose in filter paper would be processed cellulose. Thus, must be a bit more crystalline than or permanently crystalline unlike unprocessed cellulose. Higher or permanent crystallinity would require a bit more aggressive fugal cellulase activity to degrade. Fungal cellulases are able to degrade all processed and unprotected unprocessed cellulose over time. Thus, if soil fungi cellulase are not degrading filter paper within 7 days, then it must have adequate alternative substrate in soil media.
I recommend you explore ways of isolating soil fungal cellulase and bring it directly in contact with filter paper.
I did the same technique and i got a wonderful results, first you should note the moisture content of your Petri-dishes also you should wait for at least 21 days.
Hello Akwasi, Hero and Samir
Thank you all so much for your input, you have really given me food for thought.
@Akwasi, I really hadn't considered the possibility of that theory of adequate alternative substrate in the soil media which makes much more sense. Thanks for that note!
@ Hero, thank you as well for that technique, I will do that certainly because that will help me to know for certain that the fungi doesn't have any alternative substrate except for the one in agar, again thank you.
@Samir, I am glad to hear that someone has used the technique and it worked. Have you published any of that work you did on cellulolytic activity, and if yes would you mind sharing it with me?
The filter paper may have been treated with chlorine to make it "white." Have you checked for this?
If the conditions you have described in the question are correct - you did not use the method of Smith and Hughes (2001). First of all that method was developed "to determine the activity of cellulolytic microorganisms in compost" - not in soil. Secondly - the authors recommended to incubate the samples for 10 days (not 7) at 30°C (not 25).
Hi John and Tymur
@John thanks for your response and no I haven't checked that, what impact would chlorine have on the fungi?
@Tymur yes I am aware of that I guess I sshould've said and adapted version of their method, initially that's how I used to do the analysis, but I still encouted the same problem, a colleague suggested I adapt the method to see of I would get a different result also doesn't work. If I may, have you worked with the method before?
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