The Characteristics Of Cellulolytic Bacteria From Black Soil In The Farmland And Their Application In The Straw Composting

Crop straw is the richest resource of biomass in China. Many straws are burned directly in the open air every year,which led to environmental pollution and the waste of resources. Therefore,the rational use of straw energy in the focus of our attention.Straw utilization by biological treatment technology effectively will achieve good ecological effects and environmental benefits. In terms of the sustainable development of agriculture,the compost products can improve the organic substance in soil and enhance the efficiency of land utilization.In this study,11 strains of cellulolytic bacteria were isolated from black soil in the farmland.An efficient cellulolytic bacteria was choosed to study on the experiments of composting. The results of the study are as follows:1. The morphological, biochemical characteristics, as well as sequences of 16S rDNA of the isolates were analyzed. The results showed that the isolates included 8 strains of Streptomyces,one of genus Micromonospora, one of genus Actinocorallia, one of genus Pseudomonas, and numbered these strains from C-1 to C-11.2. CMCase,xylanase and nitrogenase activity of isolates were studied.The results showed that all strains can produce exocellular cellulase and xylanase. The strain of Streptomyces C-5 was the highest one which produced CMC enzyme activity with 16.75× 10^-2 IU/mL;The strain of Streptomyces C-4 was the highest one which produced xylanase activity with 6.22 IU/mL. Acetylene reduction method was used in strains nitrogenase activities analyses. The results showed that there were 7 strains capable of producing nitrogenase activity with 7.83 to 11.75 nmol C₂H₄h^-1mL^-1. And the strain of Streptomyces C-1 was the highest one with 11.75 nmol C₂H₄h^-1mL^-1.3. The study on the ability of growth promoting showed that 8 strains were capable of producing IAA which would stimulate the plants growth.The strain of C-6 was the highest one which produced IAA ?35.19 mg/L?, followed by the strain of C-5 ?14.98 mg/L?; Three strains were capable of producing iron carrier, C-2, C-6 and C-8; Only the strain of pseudomonas C-6 was capable of producing ACC deaminase activity; Most of the isolates showed their antibacterial activity against E.coli and Staphylococcus aureus significantly in the antibacterial experiments;The strain of Streptomyce C-5 was choosed as the experimental group which study on the the effects of maize seed germination.And made the analysis of variance by SPSS.The data showed that there were no significant difference between the three groups on the length of radicle and significant difference on the length of hypocotyl.4. In order to study the effects of microbial inoculum on composting,the strain of Streptomyce C-5 was choosed as the experimental group.The indexes of temperature, pH, E4/E6, microorganism quantity, C/N ratio, fiber content, seed germination index and cellulose enzyme activity were determined during the composting process.The results showed that microbial inocula were beneficial to promote the maturity of compostAnd the products of compost can be used widely in the agriculture.