Screening Of Phosphate-dissolving Bacteria And Research Of Function

Guizhou has rich mineral resources,among which phosphate rock,coal are the main production areas.In 2000,China carried out a strategic project for the development of the western region,using the abundant coal resources in the western region and to convert the energy resources of the west into electric energy through thermal power generation,and transporting it to the eastern region where energy is scarce.With the production of a large amount of coal gangue,coal gangue is a kind of waste,presenting the status quo of continuous growth,which not only occupies land resources,causes environmental pollution,but also hinders the sustainable development of coal industry.Recently,the China has gradually increased attention to the waste solid matter,which included it in the national development strategy,and the comprehensive utilization of coal gangue has become a difficult problem that needs to be solved at present.The comprehensive utilization of coal gangue is mainly use chemical method.It is found that the composition and structure of coal gangue hinder the practical application,so a green,environmentally friendly and efficient treatment method of coal gangue is explored,which is the key concern for researchers.For a long time,this research group has carried on the relatively systematic research to the coal gangue,firstly,using the flotation method to extract the carbon from the coal gangue,increasing the coal recovery rate and the utilization rate.Including a few of carbon,coal gangue is also have rich minerals,including phosphorus,potassium and so on.Phosphorus is one of the essential nutrients for plant growth and development.If it is fully utilized,it will make coal gangue can be secongly used in the future,but also solve the problem of phosphorus deficiency in soil.Previous studies have found that the use of commercial phosphate-solubilizing and potassium-releasing bacteria can effectively release the mineral components rich in coal gangue.Through extensive sampling and research on the ecological environment in the coal-producing areas in Guizhou,foundly that the phosphate-solubilizing and potassium-solubilizing bacteria autonomously screened for regional ecological conditions have the ability to dissociate coal gangue more efficiently.In this dissertation,a combination of plate method and sand culture method achieve new and efficient strains of phosphate-solubilizing bacteria.Using the new biological bacteria developed,the insoluble phosphate in coal gangue can be converted into soluble phosphorus to prepare coal gangue microorganisms.Compound fertilizers make it possible to use coal gangue resources.In this dissertation,more than 90 strains of bacteria with phosphate-solubilizing effect were obtained through the method of plate screening.Twenty strains with good phosphate-resolving ability were selected and numbered as GZ-1 to GZ-20.We used this strains that preliminary screened of bacteria to dispose the coal gangue,through testing the content of effective phosphorus in that processing simples,we checked out three strains of phosphate-dissolving bacteria,the serial number of them were GZ-8,GZ-12 and GZ-15.And we did research on the physiological and biochemical properties of the above three strains of bacteria,as well as 16 S r RNA molecular biology identification.The results of 16 S r RNA molecular biology identification were as follows: the strain GZ-8 was Myroides odoratimimus strain.Hubei China PIM10(GQ359964)in the database of NCBI,the homology was 99%,combined appearance observation,it is Myroides odoratimimus strain;the strain GZ-12 was Providencia stuartii strain.Kisarazu Japan NBRC 12930(AB680338)in the database of NCBI,the homology was 99%,combined appearance observation,it is Providencia stuartii strain;the strain GZ-15 was Wautersiella falsenii strain.Yunnan China CD-145(JQ724534)in the database of NCBI,the homology was 99%,combined appearance observation,it is Wautersiella falsenii strain.Using GZ-8(Myroides odoratimimus strain)obtained by screening,the commercial bacterium Bacillus megaterium was selected as a control strain to study the gangue,and the gangue particle size,system p H,inoculation amount,and culture time were studied by single-factor experiments.Based on the single factor experimental results,the L9(3)4 orthogonal test was designed to obtain the best conditions for the bacteria to disassociate from coal gangue.The results showed that the best conditions for dissolving gangue with GZ-8 bacteria were as follows: gangue particle size 120 meshes,bacteria inoculation amount 50 m L(ie the concentration of bacteria in GZ-8 bacteria was 1.46×1013 cfu/m L~1.87× 1013cfu/m L),the system p H is 8,the culture time is 3d.The phosphate-removing capacity of GZ-8 bacteria(the effective phosphorus content increased 41.46 mg/kg compared with the original ore sample)was better than the control strain(bacillus megatherium increased 30.33 mg/kg).The research found that coal gangue contains less phosphorus,which is not enough to produce phosphate fertilizers that meet the requirements.The increase of phosphorus in the coal gangue is the key to solving the problem.The best conditions for the preparation of microbial compound fertilizer by using GZ-8 bacteria dissociated and doped phosphate rock coal gangue by doping the coal gangue with low-grade primary phosphate rock are as follows: phosphate rock: coal gangue is 4:1,The inoculation amount was 50 m L(ie,the concentration of bacteria in GZ-8 bacteria was 1.46×1013 cfu/m L to 1.87×1013 cfu/m L),the p H of the system was 10,and the culture time was 4 days.The phosphate-removing capacity of GZ-8 bacteria(the effective phosphorus content was 97.22 mg/kg higher than that of the original ore)was higher than that of the control strain(Bacillus megatherium 69.94 mg/kg).The results show that: different kinds of highly efficient phosphate-solubilizing bacteria can be screened out from the weathered minerals in the mining area and the surrounding soil.Its ability to disassociate coal gangue is superior to that of commercial phosphate-solubilizing bacteria,and the range of understanding of phosphorus microbial bacteria is further expanded,laying a good foundation for the development of more excellent phosphorus-solubilizing microbial bacteria in the future.The use of microbial treatment method,compared to other methods of coal gangue treatment,with the advantages of small pollution,simple operation,low equipment requirements and easy access to raw materials.Compared with conventional fertilizers,the coal gangue microbial compound fertilizers prepared by the method can provide phosphorus needed for plant growth,and also reduce the negative impact brought by traditional fertilizers.At the same time,it can also improve the quality of soil and develop soil for future development.The new fertilizers provide new ideas and build new bridges between chemical fertilizers and bio-fertilizers.