| With the rapid development of urban greening construction,the production of garden waste continues to increase,and the treatment and effective utilization of garden waste is an important way to achieve recycling and green development.Composting is one of the most convenient and practical ways to utilize garden waste efficiently.However,natural composting of garden waste has problems such as long cycle time and lignocellulose is not easily degraded.For this reason,in this study,samples were collected from different environments,and the lignocellulose-degrading fungi were screened by dilution plate method to isolate fungal strains,Congo red and aniline blue color reaction and liquid enzyme-producing activity,etc.Morphological and molecular biological characteristics were used to identify the lignocellulose-degrading fungi for efficient decomposition of garden waste,and at the same time,the fermentation conditions were optimized for efficient degradation of garden waste fungi.The application effect of garden waste compost was tested by solid-state fermentation tests in order to explore the changes of physical and chemical properties of materials during composting,and potting tests.This study provides excellent strains and combinations of lignocellulose-degrading bacteria suitable for the aerobic composting of garden waste,and also provides a feasible way for the resource utilization of garden waste.The specific research contents and main results are as follows:(1)A total of 109 fungal strains with different appearance were isolated from humus,cow dung,horse dung,dead leaves,compost,straw and other samples collected from different regions of Tibet,and the results showed that 40 fungal strains,accounting for 36.7% of the test strains,discolored the aniline blue medium,and 32 fungal strains,accounting for 29.4% of the test strains,formed transparent circles in sodium carboxymethylcellulose medium,while 11 fungal strains,accounting for 10.0% of the test strains,discolored the aniline blue medium and formed transparent circles in sodium carboxymethylcellulose medium.The number of fungi that could discolor Aniline Blue medium and form transparent circles in sodium carboxymethylcellulose medium was 11 strains,accounting for 10.0% of the test strains.(2)The 14 strains of lignin-degrading fungi with high degree of PDA-aniline blue medium discoloration and filter paper disintegration test screened 16 strains with high degree of disintegration for liquid enzyme production test,and the strains with high enzyme production activity were subjected to 3-strain composite enzyme production activity assay,and the results showed that: the overall activity of lignin-degrading enzyme of lignin-degrading composite bacteria T1-16+T2-54+T1-24 was high,laccase,lignin peroxidase,and manganese peroxidase were 6.13U/m L,30.48 U/m L,and 84.79 U/m L,respectively,and the overall cellulase activity of cellulose complex BF32-93+BF31-32 cellulase activity was higher,and carboxymethyl cellulase,filter paper enzyme,and microcrystalline cellulase were 52.92 U/m L,25.68 U/m L,and 32.39U/m L,respectively.(3)In this test,strains T1-16,T1-24,T2-55,BF31-32 and BF32-93 were identified using a combination of morphological and molecular identification methods.The results showed that strain T1-16 was Fusarium asiaticum,strain T1-24 was Fusarium equiseti,strain T2-55 was Marquandomyces marquandii,and strain BF31-32 was Penicillium brevicompactum;strain BF32-93 was Aspergillus udagawae.(4)The lignin-degrading fungi T1-16 and T1-24,cellulose-degrading fungi T2-55,BF31-32 and BF32-93 were optimized in four aspects of strain inoculum,initial p H,incubation temperature and shaker speed to screen the conditions suitable for their enzyme production.The results showed that the suitable inoculum of lignin-degrading fungi was 4%～8%,the suitable p H was 6～8,and the suitable growth temperature was 25～35℃;the suitable inoculum of cellulose-degrading fungi was 6%～10%,the suitable p H was 6～8,and the suitable growth temperature was 20～40 ℃.Among them,the inoculum amount of the strain and the culture temperature have a greater influence on the rate of leaf degradation in the process of enzyme production by the strain.(5)Garden waste complexes such as leaves,grass clippings and pine needles were crushed and used as raw materials for garden waste composting tests on single strains T1-16,T1-24,T2-55,BF31-32,BF32-93 and composite strain BF32-93+T2-55.The results showed that the composting process conformed to the general rule of organic matter decomposition and metabolism by microorganisms in compost fermentation.Except for the blank control CK and the unsterilized and uninoculated CK-SY group which did not decompose,the composting process of all other treatment groups reached the basic decomposition state within 30 d.The germination indices of composting treatments T1-16,T1-24,T2-55 and BF32-93+T2-55 all exceeded 80%.(6)The effects of garden waste compost products obtained by fermenting garden waste with single strains T1-16,T1-24,T2-55 and composite strain BF32-93+T2-55 on the growth and development,soil microbial population and soil physicochemical properties of cabbage were tested in pot experiments,and the results showed that: fertilizer +BF32-93+T2-55 garden waste compost treatment(D2),the had a significant promotion effect on plant leaf growth and plant biomass accumulation;the total number of bacteria,fungi and actinomycetes increased and the ratio of bacteria/fungi and actinomycetes/fungi increased significantly in the soil after the application of garden waste compost compared with the control group,with the most significant increase in the treatment of BF32-93+T2-55 garden waste compost(D1)alone,and the application of garden waste compost increased the soil The proportion of disease-resistant microorganisms in microorganisms enhanced soil resistance to soil-borne diseases;the fertilizer + T2-55 garden waste compost(C2),fertilizer + T1-16 garden waste compost(A2),and fertilizer + T1-24 garden waste compost(B2)treatments were analyzed by comprehensive soil evaluation,which was beneficial to the enhancement of soil physicochemical properties. |
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