Asked for help: the effect of inoculation in composting processes - (Sep/29/2008 )
Hello everyone!
Our aim is to isolate some functional microorganism and inoculate them to the composting of straws(tobacco risdues), in order to improve the process of the composting(e.g. shorten the periond, or improve the quality) . However,we all know that the use of inoculants to improve the composting process has been a controversial subject, though our teacher affirmed the effects of the inoculation, we still fill a little confused, and have some questions to ask.
To use inoculation to improve the composting, there are two main aspects, one is to accelerate the heating-up of the composting, the other is to increase the cellulose-lignin degradation in the thermo-stage, so:
1.In the early stage of the composting, the rise of the temperature is due to the degradation of the dissoluble subtrates, such as sucrose, starch, amino acid, protein, and so on, therefore, in order to acclerate the rise of the temperature of the composting, we can isolate the microorganisms that can strongly decompose these subtrates, is it OK?
2.When the composting has come to the thermo-stage, the dissoluble subtrates has nearly been completely decomposed, then the cellulose-lignin( cellulose, hemicellulose and lignin)began to be decomposed. Though the amount of the bacterias is very enormous, the activity of the extracellular cellulose-enzyme is very low, and few bacteria is able to break down the lignin; in the opposite, the activity of the extracellular cellulose-enzyme of fungi is much higher than bacteria, and the mechanical action of the hypha of the fungi can help to the break down of the cellulose, also many fungi can decompose the lignin. In addition, the actinomycetes are similar with the fungi, therefore, our focal point is to isolate the thermo cellulose-lignin degradating fungi and actinomycete, is it reasonable?
We can isolate these thermo fungus from the composting of the dairy manure, but can these microganisms be dominant in the composting system of tobacco straw, or at least be functional? May they maladjustment the system and disapper? We may should isolate isolate these fungus from the soil planting the tobaccos, but there is few thermo-fungi, how to do?
Our teacher is very busy so we didn't have many opportunities to talk with him, so we often fell puzzled, asked for your help! Thank you very much!
Our aim is to isolate some functional microorganism and inoculate them to the composting of straws(tobacco risdues), in order to improve the process of the composting(e.g. shorten the periond, or improve the quality) . However,we all know that the use of inoculants to improve the composting process has been a controversial subject, though our teacher affirmed the effects of the inoculation, we still fill a little confused, and have some questions to ask.
To use inoculation to improve the composting, there are two main aspects, one is to accelerate the heating-up of the composting, the other is to increase the cellulose-lignin degradation in the thermo-stage, so:
1.In the early stage of the composting, the rise of the temperature is due to the degradation of the dissoluble subtrates, such as sucrose, starch, amino acid, protein, and so on, therefore, in order to acclerate the rise of the temperature of the composting, we can isolate the microorganisms that can strongly decompose these subtrates, is it OK?
2.When the composting has come to the thermo-stage, the dissoluble subtrates has nearly been completely decomposed, then the cellulose-lignin( cellulose, hemicellulose and lignin)began to be decomposed. Though the amount of the bacterias is very enormous, the activity of the extracellular cellulose-enzyme is very low, and few bacteria is able to break down the lignin; in the opposite, the activity of the extracellular cellulose-enzyme of fungi is much higher than bacteria, and the mechanical action of the hypha of the fungi can help to the break down of the cellulose, also many fungi can decompose the lignin. In addition, the actinomycetes are similar with the fungi, therefore, our focal point is to isolate the thermo cellulose-lignin degradating fungi and actinomycete, is it reasonable?
We can isolate these thermo fungus from the composting of the dairy manure, but can these microganisms be dominant in the composting system of tobacco straw, or at least be functional? May they maladjustment the system and disapper? We may should isolate isolate these fungus from the soil planting the tobaccos, but there is few thermo-fungi, how to do?
Our teacher is very busy so we didn't have many opportunities to talk with him, so we often fell puzzled, asked for your help! Thank you very much!
So you are basically asking (1) if its possible to isolate the bacteria responsible for the heating up of compost, and (2) if its a good idea to inocculate the compost with actinomyces when the thermo-stage is reached, and how to do that, correct? In answer to your first question, yes, it is possible to isolate the bacteria responsible for the heating of compost. To do so, I would prepare a general purpose liquid broth such as TSB (trypticase soy broth), and inocculate a flask filled about 1/4th full of the broth with a pea-sized amount of some compost that is in the heated-up stage; make sure that the broth media has been sterilized by autoclaving before the addition of the compost. Place the flask on a shaking incubator for 24 hours at 37 degrees C, and check for growth; the liquid will be cloudy if there is bacteria growing. Then, streak some agar plates with your liquid culture in an effort to isolate some colonies. If the colonies look fuzzy, then its likely they are fungi. After you isolate some colonies, you can just inocculate another flask of sterile liquid medium with a colony picked from your plate, allow to grow for 24 hours at 37 degrees C, and then pour the culture over the compost.
To answer your second question, it makes sense that isolating the actinomyces from cow manure would speed up the thermo-stage, and you could basically do the same thing I explained in your first question, except you would want to inocculate with composted manure/soil sample from tobacco roots, and use a medium that fungi like better, such as saboraud dextrose broth. As for your question about whether the actinomyces could become the dominant fungi, the only way to test that is to try it and see.
If you know the species of the bacteria and fungi, you can go a step further and buy or make a specalized medium for the species you are trying to isolate; to find out what species you are working with, just run some biochemical tests on some of the isolated colonies that you get on the plates you streak with the liquid culture. Then, make the specialized media, and inocculate liquid flasks, and incubate. Doing the process with specialized media will simply lessen the chance of contamination with an unwanted microorganism.
Hope that helps!
Thank you very much for your advice!
About Q1, the method is very good, also I want to ask that does inoculation have much effect on the heating-up of the compost,? Someone said that the compost can heating-up quickly and spontaneously, is it right?
About Q2, I want to know that in the thermo-stage of the composting, which contributes most to the degradation of the cellulose-lignin, the bacteria, the actinomycete, or the fungi?