The Relationship Of Microbial Diversity And The Transformation Of Material In The Composting Process Of Agricultural Organic Solid Wastes

Cow dung added with a small amount saw dust, and rice hull, after full mixed, wascomposted in the equipment which was designed by us. The relationship of microbialbiodiversity and the transformation of composting materials in the composting process ofagricultural organic solids matters were determined.The microbial biodiversity and the development pattern of microbial group in thecomposting process were studied by culture microbial method and un-culture microbialmethod, molecular biology method (denaturing gradient gel electrophoresis, DGGE),respectively.The culture microbial method had shown that the bacterium was dominant position todecompose the materials at the beginning composting stage and theirs number was therange of 8.1×10⁸～1.2×10⁹ CFU g^-1 during the composting process. When the compostingbody reached the thermophilic phase, the number of bacterium decreased, then theactinomycetes was superiority to brake down the composting materials and the number ofactinomycetes was the scope of 1.0×10⁶～1.1×10⁷ CFU g^-1. When the compostingprocess got to cooling phase and maturation phase, the fungi was preponderance todecompose the composting materials and the number of fungi was the scope of 1.0×10⁵～5.6×10⁷ CFU g^-1.The culture method had made known that composting was given impetus to forwardunder the common action of bacteria, actinomycetes, fungi, but their dominant positionwere different under the different composting stage.The un-culture microbial method, denaturing gradient gel electrophoresis, had madeclear that the similarity of bacteria, actinomycetes biodiversity communities was connectedwith the composting process; however, the similarity of fungi biodiversity communities wasdifferent with bacteria, actinomycetes. Such as, the biggest percent of the similarity ofbacteria biodiversity communities was 92% between the first day and the fourth daycomposting samples and the smallest percent of the similarity of bacteria biodiversitycommunities was 30% between the second day and the sixtieth day composting samples. At the beginning composting stage, there had been little actinomycetes, however,theirs number and kinds were smaller than that of the latter composting stage. With thecomposting, theirs number and kinds had become more and more. There was a positiveconnection between the percent of the similarity of actinomycetes with composting process.The changes of fungi biodiversity communities were different with the changes ofbacteria, actinomycetes biodiversity communities in the composting process of agriculturalorganic solids matter. On the contrary with the changes of bacteria, actinomycetesbiodiversity communities, the changes of fungi biodiversity communities was no relatedwith the composting process. The fungi biodiversity communities at the end of compostingprocess were more abundant than that of other composting stages.The Infrared Spectrum (IRS) annalistic technology was directly applied to study thedecomposition process of cow dung added with a small amount saw dust and rice hull. Theresult showed that infrared spectroscopy could indicate the dynamic changes of organiccomponents in the composting process. With the progress of composted materialsdecomposition, hydroxyl, ketonic carbonyl, methyl, methylene, methine and aliphaticcompounds decreased, but aromatic compounds increased, which meant that thecarbohydrates and aliphatic compounds decomposed quickly and lignin decomposed slowly.In the composting process, carboxyl existed as carboxylic ions, most carbohydrates andaliphatic compounds were oxidized to CO₂ and H₂O, the proteins and amino acids weredecomposed to CO₂, NH₄⁺, NO₃^- and amides, and the lignin were decomposed tohydroquinones. The change of materials contained with carbon and nitrogen resulted invariance of ratio of carbon and nitrogen (C/N). The change of C/N might be one of themain reasons of microorganism evolution in the composting process of agricultural organicsolids matters.An experiment was conducted to analyze on the low molecular weight organic matters(LMWOM) in composted production with/without NMF inoculants by Solid PhaseMicroextraction - Gas Chromatogram - Mass Spectrum (SPME - GC - MS). The results hadshown that there were a large number of low molecular weight organic matters incomposted productions. As far as these organic matters were concerned, there were as muchsixteen kinds of low molecular weight organic acids and Aldehyde, Alcohol, Ketone,Carboxylic acid, Carboxylic acid, Furan, Pyrazine, Fat hydrocarbon, sulphide, benzoic acid,limonene and so on. This study had also shown that kinds and content of. LMWOM incomposting samples with inoculants were much more than that in composted samples without NMF inoculants.The amounts of acetaldehyde, acetic acid, and nonaldehyde acide in compostedproduction was stable and high, which meant they might be one of the judgments ofcompost maturity. This study had extracted the two new bio-active material, limonene andbenzoic acid from composted production. Benzoic acid could promote the growth of plantor control development. Limonene could prevent and cure of plant diseases and insect pestof pine tree.The analysis of the low molecular weight organic matters in composted production bySPME - GC - MS technology supplied the detail data for the function of biology andchemistry when the composted production was applied into soil. At the time, such studymight be regarded as a significant explore for selected the composting micro-organisminoculants which could produce and accumulate such low molecular weight organic mattersin this field.A method for the determination of crop nutrition element - Potassium iron (K⁺) inorganic fertilizer samples was established based on the combination of discrete wavelettransform (DWT) and near-infrared spectroscopy (NIRS) technique. Potassium in organicfertilizer can be determined by NIRS technique, because they were combined with organicgroups with NIRS absorption. In the proposed method, the raw NIRS data and their waveletcoefficients are used for modeling and prediction of the contents of potassium in organicfertilizer by partial least square (PLS) method. It was shown that there was almost no lossof spectral information with the NIRS data compressed to 3.6% of its original size. Themodel based on wavelet coefficients was better than that based on the full NIRS spectralrange. With the improved method, accurate prediction could be achieved.The results had shown that the method of NIRS was as the same as the method ofGravimetric potassium tetraphenylborate (GPT) and Atomic Absorption Spectrometry(AAS) in determination of potassium of composted product, but the reappearance of NIRSmethod was much more than that of AAS and GPT method in the detection of Potassiumiron (K⁺) in composed production.