Study Of Nitrogen Transformation Microorganism In Ectopic Fermentation System

Ectopic fermentation system(EFS)is an advanced technology which can achieve pollution-free and zero-emission with continuous dynamic fermentation by microorganism.It solves the pollution of manure from breeding plants.However,nitrogen will be released into the air in the form of NH3,N2O,which will not only lose nitrogen resource but also pollute environment.In addition to the adsorption of pad materials,functional bacteria reduce the gas release and improve the performance of fermentation products.Based on previous studies,the study measured the changes of fermentation temperature,pH,NH4+-N,NO3--N and TN content during fermentation process.By exploring the diversity and community succession of functional microorganisms,the functional genus suitabled for EFS were determined.Finally,the correlation between functional microorganisms and environmental factors was clarified.The main conclusions of the study are as follows:(1)The temperature,pH,NH4+-N,NO3--N and TN showed a trend of increased.The moisture was controlled between 40%and 65%.The species richness and community diversity of bacteria showed an increasing trend.Truepera and Clostridium increased significantly.Pseudomonas,and Massilia decreased with fermentation.The species richness of fungi decreased and the communiity diversity increased.Thermomyces and Mycothermus were more popular in spring-summer group.Aspergilus and Emericola were reduced.There was increase of Aspergillus and Thermomyces,but decrease of Kondoa and Fusarium.(2)The species richness and community diversity of AOB increased.Nitrosomonas,Nitrosospira,and Nitrosovibrio were the dominant bacteria,Nitrosomonas increased and replaced Nitrosovibrio as the dominant bacteria,The species richness and community diversity of denitrifiers carrying nirK and nosZ decreased.Pseudomonas as the mainly denitrifying bacteria decreased in fermentation process.But Pusillimonas,Alcaligenes and Thalassobaculum increased.Nitrosomonas was the dominant AOB when the pH value and NH4+-N was greater than 8.0 and 1.0 mg/g.The domiant denitrifiers carrying nirK,Pseudomonas was suitable for the pH less than 7.5 and the NH4+-N less than 0.2 mg/g.Mesorhizobium and Luteimonas,with the largest proportion in autumn-winter group,were suitable for pH greater than 9.0 and NH4+-N greater than 2.0 mg/g.The domiant denitrifiers carrying nosZ gene,Pseudomonas was suitable for the pH less than 7.0 and NH4+-N and NO3--N were less than 0.2 mg/g.In fall-winter group,Pseudomonas was suitable for the pH of 9.2 and NH4+-N content of 0.8 mg/g.(3)For AOB,Nitrosomonas had positive correlation with enviroment factors.Nitrosospira and Nitrosovibrio were correlated negatively with the environment factors.For denitrifiers corresponding to nirK,Pseudomonas was negatively correlated with temperature,pH,NH4+-N,NO3--N and TN.Mesorhizobium and Luteimonas were positively correlated with pH,temperature,NO3--N,and TN.In spring-summer group,the comprehensive effects of physicochemical factors and nitrogen sources have a larger explanation on AOB diversity.While in fall-winter group,the explanation of physicochemical factors in AOB diversity was larger than the comprehensive effect.Denitrifying bacteria carrying nirK were influenced by the surroundings,while nosZ denitrifying bacteria are greatly affected by temperature,pH and moisture content.This study revealed the role of functional bacteria in gases removal of EFS,and provided a theoretical basis for the improvement of microbial agents and EFS.