Different Inoculants On The Cow Dung Composting Process And The Microbialcommunity Dynamics Research

In this experiment,different Bacillus subtilis and yeast compound agents were inoculated in the process of cow manure composting to study the effect of the compost.Cattle dung and corn stalk were mixed in a ratio of 3:1 for fermentation.The experiments were divided into control group(without any bacterial agent),treatment group 1(0.5% Bacillus subtilis: yeast =1:1)and treatment group 2(0.5% Bacillus subtilis: yeast =1:3),with 3 replicates in each group.After 49 days of compost treatment,every 7 days for a period of time,under the conditions of inoculation of different bacteria,the reactor temperature,p H,total phosphorus,available phosphorus,total potassium,available potassium,total nitrogen,ammonium nitrogen,electrical conductivity,organic matter and other indicators of the change of the reactor,that is,to compare the effects of the two proportions of bacteria compost.Microbial samples were collected at each representative time point of compost fermentation.Total DNA of the compost was extracted according to the Mobo Power Soil(?) DNA Isolation Kit(12888)method,and high-throughput sequencing was performed.After sequencing,The original data was assembled with PE reads,Tags filtered,and chimerism removed.UCLUST and MOTHUR software in QIIME were used to cluster Tags at 97%similarity level to obtain OTUs.Based on Silvade bacteria database and Unite fungus database,the OTUs were obtained.Taxonomic annotation and analysis of OTU were carried out in the taxonomic database,and community composition of each sample was counted at the level of each taxonomic genus.At the same time,the Alpha diversity index of the samples was estimated,the Shannon index curve,the grade abundance curve and the dilution curve were plotted,and the microbial correlation analysis was performed.The results showed as follows: in the process of composting,through the measurement of nutrient indexes,the indexes of the three groups at the end of this experiment were all in line with the composting maturity indexes,but there was no significant difference in the decomposition of p H,total nitrogen,total phosphorus,total potassium,cellulose,hemicellulose and lignin between treatment group 1 and treatment group 2(P > 0.05).Compared with the control group,treatment group 1 could effectively promote the decomposition of organic matter,significantly increase the content of available phosphorus,and significantly shorten the time for compost ripening(P < 0.05).After adding microbial fermentation agents to the reactor,a total of 8 Phylum,20 Class,43 Order,81 Family,158 Genus and 211 Species were obtained from the sequencing samples.The abundance and diversity of microorganisms in the reactor were increased.The fungi and bacteria in the pile have dynamic changes in community composition.Fungi and bacteria showed the same changing trend in OTU operating taxon and Shannon diversity index,both showing a changing trend of increasing in the early fermentation period and decreasing in the later fermentation period.Therichness and diversity of bacterial community were higher than that of fungal community.In the process of fertilizer,the dominant bacteria genera were obviously different and changed at the genus level,and the community structure of bacteria in the early composting period,high temperature period and decomposing period had obvious alternation.On the 49 th day,the dominant bacteria genera were Hydrogenispora,Bacteria-O-SBR1031 and Bacteria-F-Rhodother Mac Eac.In the late composting period,Bacillus subtilis and yeast(1:1)compound preparation had inhibitory effect on Bacterium SBR and Chyseolinea,but promoted Rhodothermaceae.In the process of composting,the dominant fungi were significantly different and changed at the genus level.The dominant fungi on the 49 th day were: Mycothermus,Coprinopsis,Aspergillus,Remersonia,Bacillus subtilis and yeast(1:1)combined preparation of Mycothermus and Zopfiella It has a catalytic effect.In conclusion,the compound preparation of Bacillus subtilis and yeast(1:1)has positive effects on decomposition of organic matter and increase of available phosphorus,and can improve the abundance and diversity of microorganisms.