Screening Of Phosphate-dissolving Bacteria And Its Properties

Phosphorus and potassium,as essential elements for plant nutrition,play a vital role in plant growth and development.Phosphorus deficiency and potassium deficiency are present in most areas of China,because most of the phosphorus and potassium in the soil exist in the form of insoluble phosphorus and insoluble potassium.Therefore,agricultural cultivation can only be carried out by external application of phosphate fertilizer.Potassium forms supplement the phosphorus and potassium that are missing during plant growth and development.With the massive exploitation of phosphate rock and potash mine,China's phosphate rock and potash resources are increasingly scarce.Coal gangue is a kind of waste with low carbon content produced during coal mining,accounting for about 15% of coal production.As a large coal-producing province,Guizhou has an annual coal output of about 100 million tons,accumulating a large amount of coal gangue.At present,the comprehensive utilization rate of coal gangue is relatively low,mainly including chemical methods and physical methods.These methods cannot be applied to production in large scale due to various conditions.Through the analysis of the composition of coal gangue,it is rich in mineral components,such as N,P,K,Ca,Mg,Al,etc,where P and K are essential elements for plant growth and development,if they can be used in coal gangue The dissociation of P and K and their full utilization can not only solve a series of problems of massive accumulation of coal gangue,but also solve the current situation of soil nutrient deficiency.However,the traditional method of using coal gangue can not solve this problem well,and the method of microbial dissociation dissociates the insoluble phosphorus and potassium in coal gangue to prepare coal gangue fertilizer,which is green and efficient.And environmental protection methods.The preliminary research work in the laboratory found that some strains can effectively dissociate the insoluble phosphorus and potassium in coal gangue.Based on this research,this paper uses the poorly soluble inorganic phosphorus medium for primary screening and sand culturing.The method was to screen out a number of new high-efficiency phosphatedissolving and potassium-dissolving strains,and the new bacteria obtained by screening were used to study the solution of phosphorus and potassium in coal gangue,and to find out the best conditions for the strain to dissociate coal gangue and prepare coal gangue microorganisms.Compound fertilizer.Coal gangue microbial compound fertilizer not only overcomes the shortcomings of traditional chemical fertilizers,but also provides a new possibility and direction for the utilization of coal gangue resources.In this paper,130 strains with certain phosphate-dissolving effects were obtained by initial screening of the collected soil samples on the poorly soluble inorganic phosphorus solid medium,and named GJ1-GJ130.Six strains of highly efficient phosphate-dissolving and potassium-dissolving strains were obtained by re-screening by sand culture and comparison with commercial strains.Among them,GJ10,GJ116,GJ125 are phosphate-dissolving strains,and GJ44 and GJ72 are potassium-dissolving strains.The morphology of the colony of the strain was observed,Gram staining,16 S r RNA determination and phylogenetic tree analysis.The dissociation of coal gangue by GJ116 and GJ125 with the best phosphatedissolving ability was carried out,and compared with the commercial strain Bacillus megaterium.The four main factors of dissociating coal gangue were studied by single factor,and the best one was selected.Univariate experiments were carried out under the single factor conditions,and the conditions for optimal dissociation of coal gangue were obtained.The results showed that the best dissociation conditions for GJ116 strain were 6 days culture day,the p H of the system was 4,and the inoculation amount was 80 ml(2.75×10⁹¹.34×10¹⁰ cfu/m L): the best dissociation conditions for GJ125 strain The growth time was 7 days,the p H of the system was 6,and the bacterial inoculation amount was 60 ml(2.72×10⁹¹.29×10¹⁰ cfu/m L),which was better than the control strain Bacillus megaterium.According to the results of orthogonal experiments,the strain was dissociated from coal gangue and the coal gangue fertilizer was preliminarily prepared from 10 g to 100 g,and the available phosphorus and available potassium were measured.Tobacco was selected for the effect of coal gangue fertilizer,and the same growth of tobacco seedlings was selected.Three different concentrations of gangue fertilizer were applied and compared with commercial fertilizers and Simultaneous blank control.The plant height,leaf length and leaf width of tobacco were measured regularly.Experiments show that the coal gangue fertilizer prepared in the laboratory has a certain promoting effect on the growth and development of plants.