Study On The Technology Of Producing Microbial Fertilizers From Partial Waste Of Chicken,Duck And Sheep By Fermentation

At present,residual wastes of livestock and poultry are generally processed into feeds,or treated as wastes,which not only causes resource wastes but also causes environmental pollution.It has great significance to apply the microorganism to prepare microbial fertilizers by fermenting leftovers,which can achieve the reasonable utilization of wastes from livestock and poultry,improve the usage efficiency of resource utilization rates and economic benefits,reduce pollution problems as well as effectively improve the environment.In this study,residual wastes from sheeps,chickens and ducks,used as raw materials,were fermented by the following strains of Bacillus subtilis,Bacillus cereus,Penicillium citreonigrum and Aspergillus oryzae.The best fermenting conditions for residual wastes of sheeps,chickens and duck were optimized with the total nitrogen content of the fermented products as the assessing indicator.The effect of fermented temperature,pH value,inoculum concentration and rotational speed on the total nitrogen content during the fermentation of goat,chicken and duck wastes,was analyzed to assess the fermentating suitability with a comparison between single strains and mixed strains by the design of Box Behnken?BBD?using Design Expert8.0.6 software.The nitrogen content in sheep wastes fermented by Bacillus cereus was highest to 18.8mg/mL,which was 1.5 times as much as the blank.The fermentation experiment of mixed strains showed that the optimum ratio of Bacillus cereus,Bacillus subtilis,Penicillium citreonigrum and Aspergillus oryzae was 1:1:1:1,with the resultant nitrogen content of 30.2mg/mL,2.5 times as much as the blank.Therefore,mixed strains with the best ratio of 1:1:1:1were selected for the following fermentation test.The order of the influence of different factors on total nitrogen content was:inoculation quantity>temperature>pH>rotation speed.The optimum conditions of fermentation were temperature 30°C,pH 6.00,inoculation amount10%,and rotation speed 160 r/min.Under these conditions,the content of nitrogen,phosphorus and potassium was 37.16±1.78 mg/mL,20.4±0.06 mg/mL and 19.7±0.08 mg/mL,separately.the total nutrient content?N+P₂O₅+K₂O?was 7.68%.The nitrogen content in chicken wastes fermented by Aspergillus oryzae was highest to11.18 mg/mL,which was 1.7 times as much as the blank.The fermentation experiment of mixed strains showed that the optimum ratio of Bacillus cereus,Bacillus subtilis,Penicillium citreonigrum and Aspergillus oryzae was 1:1:1:1,with the resultant nitrogen content of 18.89mg/mL,2.9 times as much as the blank.Therefore,mixed strains with the best ratio of 1:1:1:1were selected for the following fermentation test.The order of the influence of different factors on total nitrogen content was:pH>rotation speed>inoculation quantity>temperature.The optimum conditions of fermentation were temperature 30°C,pH 7.30,inoculation amount15%,and rotation speed 160 r/min.Under these conditions,the content of nitrogen,phosphorus and potassium was 21.13±0.30 mg/mL,20.01+0.09 mg/mL and 18.9+0.08mg/mL,separately.the total nutrient content?N+P₂O₅+K₂O?was 6.04%.The nitrogen content in duck wastes fermented by Bacillus subtilis was highest to 8.45mg/mL,which was 1.4 times as much as the blank.The fermentation experiment of mixed strains showed that the optimum ratio of Bacillus cereus,Bacillus subtilis,Penicillium citreonigrum and Aspergillus oryzae was 1:1:1:1,with the resultant nitrogen content of 18.08mg/mL,3 times as much as the blank.Therefore,mixed strains with the best ratio of 1:1:1:1were selected for the following fermentation test.The order of the influence of different factors on total nitrogen content was:pH>rotation speed>inoculation quantity>temperature.The optimum conditions of fermentation were temperature 30.5°C,pH 7.50,inoculation amount 15%,and rotation speed 150 r/min.Under these conditions,the content of nitrogen,phosphorus and potassium was 20.26+0.30 mg/mL,20.0+0.06 mg/mL and 19.7±0.06 mg/mL,separately.the total nutrient content?N+P₂O₅+K₂O?was 6.00%.