Screening Of Dominant Bacteria In Chicken Manure Composting And Preparation Of Compound Solidified Bacteria

With the rapid development of livestock and poultry breeding industry in China,the problem of livestock and poultry manure is becoming more and more serious.Microbial composting is a low-cost,safe and reliable way of resource utilization in line with China's national conditions.Inoculation of exogenous microorganisms can accelerate the composting process,shorten the fermentation cycle and improve the quality of composting.In this paper,the composting samples of a certain scale chicken farm in Anhui in different periods of composting were taken as the research object.The high-throughput sequencing analysis of the dominant bacteria in different composting periods was carried out.Three strains were screened out based on the decomposition performance of fat,starch,cellulose,gelatin and physiological and biochemical tests at the same time,Bacillus also conducted a single factor study on the conditions of strain growth and enzyme production to optimize the culture conditions.Finally,the indexes of zeolite powder,wheat husk powder,rice husk powder and corncob powder were compared,such as water absorption performance,p H,effective live bacterial rate of bacterial inoculation and bacterial storage period,and the best bacterial carrier was determined and solid compost was prepared.The main findings are as follows:1.Screening and identification of dominant microorganisms in chicken manure composting Collect samples from the chicken farm before composting and during the period of maturity,and explore the composition and dominant flora of the flora by high-throughput sequencing.At the same time,combined with the pure culture separation method of microorganisms,the dominant strains were screened.According to the high-throughput sequencing data,the results of bioinformatics analysis showed:In the early stage of composting,the relative abundances of phylum Firmicutes(35.48%)and Proteobacteria(26.24%)were higher;in the middle stage of composting,Actinobacteria(9.4%)and Deinocococccus-Thermus(16.69%)were higher;in the mature stage,Actinobacteria(9.4%)and Bacteroides(12.20%)were higher.At the gate level,the thermogram of species clustering showed that Bacillus belonged to the dominant group at the initial stage of composting,which promoted the composting maturity.In the early stage,middle stage and decomposed stage of composting,three strains were screened and separated through pure culture of microorganisms,10 strains of microorganisms were screened,strain morphology observation,biochemical characterization of carbohydrate decomposition and metabolic substrate degradation experiments showed that three strains of bacteria were initially identified:D1(Bacillus amyloliquefaciens),D5(Bacillus thuringiensis),D7(Bacillus licheniformis).The three strains have good oil,cellulose,starch,gelatin and a variety of carbohydrate decomposing ability,and can be used as alternate strains of compost inoculants.2.Optimization of the culture conditions of the compound fungusFrom the optimization of culture conditions such as fermentation time,fermentation temperature,initial p H of fermentation,carbon source and nitrogen source of culture medium,the optimal culture conditions were determined.The results of the study showed that between 24 and 28 h,the three strains entered a stable period after fermentation,and their growth activity reached the highest.(1)Temperature effect:at an ambient temperature of 41?,the average logarithm of D1enzyme activity is 3.26±0.014 U/m L,the average logarithm of D5 enzyme activity is2.88±0.43 U/m L,and the average pair of D7 enzyme activity The value was 3.67±0.04U/m L,and the enzyme activities of the three strains were significantly different(P<0.05).(2)Effect of p H:When the p H of D1 strain in LB medium is 6.5,the average logarithm of enzyme activity is 2.11±0.07 U/m L,and the enzyme activity is the highest;when the p H of D5 strain is 7.5,the average logarithm of enzyme activity is 7.57±0.14 U/m L;when the p H of D7 strain is 7,the average logarithm of enzyme activity is 2.62±0.14 U/m L,the three strains and other gradients are significantly different(P<0.05).(3)Influence of carbon source:when maltose is used as D1 carbon source,the enzyme production in the same group is significantly different(P<0.05),with an average logarithmic value of 27.60±0.04 U/m L;when glucose is used as the carbon source for D5and D7,the enzyme production in the same group is different Significantly(P<0.05),the average logarithmic values were 19.39±0.02 U/m L and 36.78±0.03 U/m L.(4)Effect of nitrogen source:When yeast extract is used as nitrogen source of three strains,the enzyme production of each group is significantly different(P<0.05),the average logarithmic values are 1.88±0.01 U/m L and 2.15±0.01 U/m L respectively,2.18±0.01 U/m L.3.Preparation of chicken manure composite curing agentThe carrier was ground to 100 meshes(rice husk powder,wheat husk powder,corn cob powder,zeolite powder)as the research object,and the p H value,water absorption performance,viable cell attachment viability and the number of viable bacteria in different storage periods were measured by testing.It is concluded that corncob flour has good carrier performance,excellent water absorption performance(260%),low impact on the surrounding p H(7.43),effective survival rate of bacterial inoculation D1 is 115.38%,D5 is80.0%,D7 110.0%;the conclusion of the bacterial storage period is that zeolite powder is not suitable as a carrier,and the protection of corncob powder and wheat hull powder is better.D1 strain in wheat hull powder has a live count of 3.6×10~8 CFU/m L,the number of viable bacteria in corncob meal at 28 days is 3.3×10~8 CFU/m L,the difference between the two is not significant.Compared with other carriers,the protective effect of corncob on D5and D7 strains is more significant.Among them,the number of viable bacteria in D5 at 28days is 4.0×10~8 CFU/m L,and the number of viable bacteria in D7 stored in corncob for 28days is 8.3×10~8 CFU/m L.Considering comprehensively,select corncob powder as the strain solidification carrier to prepare composting compound fungus.The above research results show that:three strains of Bacillus isolated from chicken manure compost,D1(Bacillus amyloliquefaciens),D5(Bacillus thuringiensis),and D7(Bacillus licheniformis)have composting microecological agents Potential,and corncob powder is suitable as a fungus carrier,can effectively protect the activity of strains,combined with optimized culture conditions,can make compost complex fungus.