Research On Using Rapeseed Meal To Promote The Composting Fermentation Of Spent Mushroom Sustract And The Dynamic Changes Of Microbial Community

Composting technology is an effective method for harmless disposal and resource utilization of agricultural and forestry wastes.Microorganism is the main body of compost fermentation,which is the key factor to determine whether the compost can be carried out and the quality of fertilizer.Exploring the composition of microbial community structure and its change rule in the process of composting fermentation can provide a more scientific theoretical basis for the improvement and innovation of composting technology,as well as for the popularization and application of composting technology.This study with edible mushroom residue and rapeseed cake as the research object,by investigating the composting cycle of pile body temperature,p H,conductivity,and C/N and other physical and chemical indicators to reflect the degree of the pile body rotten,thus determine roughly rapeseed cake and the optimum adding proportion in the mushroom residue composting process,for other similar rapeseed cake of high nitrogen organic waste as some oil by-products,mixed bacteria such as slag of animal manure composting fermentation to provide the reference.At the same time,the high-throughput sequencing technology was used to study the composition and dynamic changes of the microbial community in the process of composting,revealing the dominant microbial community in each stage of composting,and providing beneficial help for enriching the composting theory and screening the fermentation bacteria in composting.The main research conclusions are as follows:(1)Bacterial residue composting can be fermented regardless of whether it is added with rapeseed cake and other high-nitrogen auxiliary materials,and it can enter the heating period within 12 hours,and the high temperature period when the core temperature of the pile reaches above 55℃ can be as long as 4-9 d.During the entire composting process,the p H value has been greater than 7,overall a slow downward trend,it is always weakly alkaline;the moisture content has also been on a downward trend,and finally between 45% and 50%;C/N values are also maintained the downward trend is in line with the general law of composting fermentation,and ultimately maintained at about 20;the number of seed germination has been steadily increasing during the composting cycle,and finally reached 87% to 98%.Inferring from various physical and chemical indicators,the C1,C2,and C3 composting systems in this study all reached maturity after the end of the 15-day composting cycle.Although the Ck control has entered the late stage of composting,the degree of maturity is not enough,and the C4 treatment obviously has no results,In the middle and late stages.(2)According to Ck,C1 and C2,C3,C4,a total of five different grouping processing compost physicochemical and biological data shows: add rapeseed cake each treatment can obviously promote the mushroom residue fermentation,warming faster,high temperature,long period,as well as good rotten degree,C3 rapeseed cake(20%)of the optimal treatment of compost index,compared with Ck,C1,C4 treatment,rapeseed cake in proportion to the bacteria in the sludge compost quality in 15% ～ 25%more appropriate.(3)The species and abundance of bacteria and fungi were different at different stages of composting,and the comparison before and after composting significantly changed.However,the richness and diversity of bacterial community were significantly higher than that of fungal community.Bacteria may be the key group in the process of composting.(4)Look from gate level,compost initial deformation bacteria door,thick wall door,bacteria-the Bacteroidetes door and actinomycetes four kind of door gate of the advantage of most bacteria,bacteria in the high temperature period thick wall fungus door accounted for 70% more than become optimal fungus door,door deformation bacteria times,composting and returning to the early late gate the kinds and ratio of bacteria.In fungi door,ascomycetes door the whole life cycle are absolute superiority in the compost fungi door,followed by basidiomycete fungi door,the rest of the fungi door proportion is very low,which accord with the material of compost for the actual situation of the edible mushroom residue,but can be found by spore mold gate significantly increased in the high temperature period stage,the proportion of also suggests that it is a dominant fungi door high temperature period.(5)From a genus level,Petrimonas,Ureibacillu-s,Symbiobacterium,and Bacill us have higher abundance in the initial stage of composting,but when the compost ent ers After the high temperature maturity period,Streptomyces,Mucosin-Akkermansia,Acinetobacter,etc.become dominant genera.For fungi,Microascus and Melanocarpu s are dominant in the early stage of composting,while the dominant fungal genera dur ing composting high temperature period are Xeromyces and Agrocybe,in the later sta ge,the dominant genus changed to Cutaneotrichosporon,Melanocarpus,etc.,but The rmomyces was still the dominant genus.