Synergistic High Efficiency Fermentation Technology Of Immobilized Microorganisms And Surplus Sludge

China is a large agricultural country,the vast majority of the annual straw and other wastes are discarded or improperly disposed,causing a very bad impact on China’s environment.Microbial composting is one of the best ways of animal husbandry and agricultural waste disposal,so it can transform cellulose resources such as manure and straw into safer and more stable fertilizers.However,composting generally has problems such as low efficiency and slow operation process,and up to now there is no unified index for judging composting,resulting in a lot of composting fertilizer does not meet the agricultural standards.Therefore,it is very important to select efficient composting microorganisms for agricultural waste recycling,so as to meet the needs of waste crops treatment and recycling in China.In this paper,Acinetobacter sp.XG was screened from the surface of lentinus eatus.The strain XG was immobilized by nitrate method to prepare immobilized particles and applied in the composting system of agricultural waste.Improve the efficiency of composting,promote the transformation of agricultural waste to humus,provide a high-efficient cellulose degrading strain,for the future external microbial composting to provide bacteria source.The research content mainly includes the following aspects:（1）Lentinus edodes,pumpkin,bamboo and straw were selected as the screening sources of strain,and a strain Acinetobacter sp.XG with high cellulose degradation ability was obtained from the surface of lentinus edodes.The Congo red staining transparent circle diameter/colony diameter（D/D）value of the strain was 2.20,most of the filter paper was decomposed in the disintegration experiment,and the activities of cellulase（CMCA）and filter paper enzyme（FPA）were 25.49 and 40.59 U/m L,respectively,in the cellulase production experiment.Therefore,further identification and enzyme production conditions of the strain were studied.The strain was identified as Acinetobacter XG by ecological observation and molecular identification,combined with 16S r DNA phylogenetic tree construction.（2）In this paper,the nitrogen fixation ability of the strain was measured,and it could grow on the nitrogen-free medium.The nitrogenase activity of the strain was 20.51μmol C₂H₄/（m L·h）,and it had high activity and promoted the growth of wheat.（3）In this paper,the enzyme production conditions of the strain were preliminarily explored.The enzyme production conditions showed that the CMCA enzyme activity of strain XG reached the maximum of 12.5 U/m L at 2 d,and the FPA enzyme activity reached the maximum of 37.95 U/m L at 3 d.The enzyme activities of CMCA and FPA were 13.5and 40.25 U/m L at 35℃,respectively.The maximum CMCA and FPA activity were 6.96and 27.92 U/m L,respectively,when the initial p H was 6.The maximum CMCA and FPA activity were 6.44 and 25.12 U/m L,respectively,when the initial Na Cl mass fraction was1.5%.（4）The straw degradation rate of immobilized particles of the strain was measured.The results showed that the straw degradation rate of strain XG and immobilized strain XG could reach 40.98%and 45.32%respectively after 7 days of culture in liquid medium.When the culture temperature was 35℃,the degradation rate of XG and Immobilized XG was 47.0%and 50.1%,respectively.When the initial pH was 6.0,the degradation rate of XG and Immobilized XG reached 43.0%and 47.0%,respectively.When the initial concentration of Na Cl was 1.5%,the degradation rate of XG and Immobilized XG reached42.1%and 45.7%,respectively.（5）In this paper,a small composting experiment was carried out on the immobilized particles of the strain.The results showed that the composting data,maturity status,heavy metal absorption and content of ammonium nitrogen,available nitrogen and available potassium of immobilized particles achieved good results in the small composting experiment.In this paper,the strain Acinetobacter sp.XG was immobilized and applied to compost system on the basis of physiological,biochemical and enzyme production characteristics.By monitoring the change index of composting process,the composting efficiency was obviously accelerated and the content of organic matter was obviously increased.It has a good application prospect in the field of composting in the future.