Research On High Efficiency Degrading Microbial Inoculum Of Spent Mushroom Substrate And Its Application In Composting

With the increasing demand of edible fungi,the yield of spent mushroom substrate is increasing continuously,and the environmental pollution caused by unreasonable exploitation and utilization of rice bran is brought.It is one of the effective ways to make use of the compost of spent mushroom substrate into organic fertilizer,which is also the best way to meet the situation of our country.At present,there are many problems in composting treatment,such as slow fermentation,long maturity and low quality of compost.Based on this,in order to promote composting fermentation,shorten the maturity time and improve the quality of compost,this paper systematically studied the construction and application of high efficient degradation microbial inoculum.The main conclusions are as follows:i)Four strains of high efficiency cellulose degrading bacteria,two strains of high efficiency cellulose degrading actinomycetes,and two strains of high efficiency cellulose degrading fungi were screened and identified in this paper.By enrichment culture,crossed separation,the disintegration of filter paper experiments and strains CMCase,FPase enzyme activity assay,we screened four strains of high efficiency cellulose degrading bacteria(GX-5,GX-7,GX-13 and GX-16),two strains of high efficiency cellulose degrading actinomycetes(GF-1 and GF-2),and two strains of high efficiency cellulose degrading fungi(GZ-1 and ZZ-2),The morphological,physiological and biochemical characteristics,and 16S rRNA/ITS sequences of the screened strains were identified:GX-5 is Paenibacillus,GX-7,GX-13 and GX-16 are Brevibacillus;GF-1 is Streptomyces,GF-2 is Microbispora;GZ-1 is Malbranchea cinnamomea,ZZ-2 is Microascus.ii)Optimization of cellulase producing conditions for cellulose degrading bacteria.One is to optimize the culture conditions,mainly studies the effect of medium initial pH,inoculation volume,speed and temperature of producing enzyme;the second is for the optimization of culture medium,mainly studies the effects of carbon source,nitrogen source and carbon nitrogen ratio on enzyme producing strains.The optimum fermentation conditions of strains were obtained after optimization,and strains CMCase and FPase were optimized and improved.Among them,the strain GX-5 CMCase and FPase were optimized respectively increased by 37.2%and 49.0%than before;the strain GX-7 CMCase and FPase were optimized respectively increased by 36.2%and 44.7%than before;the strain GX-13 CMCase and FPase were optimized respectively increased by 34.2%and 42.6%than before;the strain GX-16 CMCase and FPase were optimized respectively increased by 32.6%and 44.5%than before;the strain GF-1 CMCase and FPase were optimized respectively increased by 63.9%and 96.4%than before;the strain GF-2 CMCase and FPase were optimized respectively increased by 58.5%and 82.1%than before;the strain GZ-1 CMCase and FPase were optimized respectively increased by 35.9%and 28.5%than before;the strain ZZ-2 CMCase and FPase were optimized respectively increased by 24.9%and 26.5%than before.iii)A kind of high efficiency degrading microbial inoculum was developed and applied successfully on the compost of spent mushroom substrate.Using the laboratory screening,domestication and construction of high efficiency lignocellulose degrading ability of microbial inoculum HJ,JK and GX-5,the original organic fertilizer for different treatment of microbial inoculum groups,with the treatment of non-microbial inoculum as control,to study the high efficiency of different microbial inoculum on compost of spent mushroom substrate.In the whole composting process,the detection of the changes of odor and color,temperature,moisture,pH,conductivity,lignocellulose,total nitrogen and humus,and the seed germination test on compost maturity and toxicity degree were evaluated,the main results are as follows:compared to CK,HJ can significantly promote the composting inoculants,the cellulose,hemicellulose and lignin degradation rate increased by 5.1%,6.5%and 4.6%,and shorten the maturity time of 6 days.The results showed that the addition of microbial inoculun could promote the fermentation,shorten the time of compost and improve the quality of compost.Among them,the effect of microbial agents to promote decay:HJ>JK>GX-5 = the original organic fertilizer>CK.iv)The microbial community succession law was verified.The microbial community in different compost treatment system has some succession.Study on the bacterial community,along with the development of the composting process,a large number of pathogenic bacteria such as Comamonas are killed,Bacillus,Paenibacillus has become the dominant bacteria;Study on the fungal communities,along with the development of the composting process,a large number of pathogenic bacteria such as Candida are killed,Thermomyces has become the dominant bacteria.With the development of composting process,the microbial community of compost showed obvious succession law.