The Mechanism Of Degradation Of Cellulose And Its Relationship With Humus Formation By Actinomycetes

Cellulose is one of nature’s most abundant renewable resources, how to realizethe recycling use of cellulose is one of the hot topics of current research, at present, itsprocessing methods can be divided into physical method, chemical and physicalmethod, chemical method and biological method, in which mainly on microbialdegradation of biological methods became the research focus. As is known to all,microbial resources are very abundant in the soil, actinomycetes as part of the soilmicroorganisms, is the main decomposition of lingo-cellulose, chitin polymers andother high-molecular polymer. In recent years, domestic and foreign researchers havefound many actinomycetes strains which could degrade cellulose, and soil humus isformed under the effect of microorganisms which has been recognized by researchers.Then, what is the role of thallus products after degrading cellulose in the formation ofsoil humus, whether or not containing humus or humus precursor substances are stillunclear, in order to solve this problem, we have used the liquid shaking cultureexperiment, obtained the thallus products after degrading cellulose by severalactinomycetes strains(F1:Streptosporangiumsp.,F2:Streptomyces sp.,F3:Streptomycesprunicolorsp.).Then used humus quantitative extraction method and the humusassociation recommended method (IHSS) method to extract and separate alkalisoluble components, using modern analytical instrument techniques, such as elementcomposition analyzer, differential thermal analyzer and infrared spectrum analyzer forthe structural characterization about the thallus and degradation products. Which isgreat of the formation of humus, cellulose degradation mechanism, the resourceutilization of cellulose and microbial agents. The results showed that:1. Actinomycetes have different ability of degradation with glucose and cellulose.In the liquid culture of glucose, the yield of thallus products reach the maximum whencultivate25d, the order of degradation, F3>F1>F2; in the liquid culture of cellulose,the yield of thallus products reach the maximum after degrading cellulose and thesequence was, F1>F3.2. In the glucose fermentation cultivation, thallus products of the actinomycetesstrains with glucose and humic acid(HA) of the black soil have different varience：And after training, F1have lower condensation degree and crystallinity, higheroxidation degree and thermal stability. F2have lower condensation degree and oxidation degree, higher crystallinity. F3have lower condensation degree, oxidationdegree, crystallinity and thermal stability.The mycelia products of the actinomycetesstrains have higher nitrogen content. The thallus products of actinomycetes strainsunder the degradation of glucose have no carboxylic acids and carboxylic groups inthe C=O stretching vibration and C-O stretching and OH, F1degradation productshave more-OH,-CH2,-CH3and amide compounds, F2degradation products haveless-OH,-CH2,-CH3, amide compounds and benzene substances, F3degradationproducts have more carbonyl and methylene content.In the cellulose fermentation cultivation, mycelia products of the actinomycetesstrains with cellulose and humic acid(HA) of the black soil have different varience.The mianly as follows: After training, F1、F3have lower condensation degree andcrystallinity, higher oxidation degree. Amongest, F1have stronger thermal stability.F2have lower condensation degree and oxidation degree, higher crystallinity. F3havelower condensation degree, oxidation degree, crystallinity and thermal stability. Thethallus products of actinomycetes strains under the degradation of cellulose have nocarboxylic acids and carboxylic groups in the C=O stretching, F1degradationproducts have more-OH,-CH2,-CH3and aliphatic compounds, F3degradationproducts have more amide compounds.3. Under the condition of glucose liquid culture, the alkali-acid soluble(ASC)carbon content of F1、F2have a trend of declining, F3have a trend of incresing.The alkali soluble acid insoluble carbon(ASAI) content of F1have a trend of rising, inaddition to, F2、F3are on the contrary. F2and F3of the alkali insoluble fractions ofcarbon content are decreasing.Under the condition of cellulose liquid culture, The mycelia products of theactinomycetes strains with cellulose, which have less alkali soluble carbon, amongst,the carbon of the alkali soluble and acid insoluble components are more thanalkali-acid soluble components. The alkali insoluble components have more carboncontent. After training, the alkali soluble acid insoluble fractions of F1have highercondensation degree, oxidation degree are reduced and have no carboxylic acidcompounds C=O stretching vibration, with the vibration of the benzene ring, so thestructural of alkali soluble and acid insoluble and HA have the varience.