Isolation, Purification And Identification Of Phosphate-solubilizing And Potassium-solubilizing Bacteria From The Rhizosphere Of Corydalis Yanhusu

Corydalis yanhusuo W.T.Wang,as the raw material of many traditional Chinese patent medicines and simple preparations,is in short supply in the market,so it is urgent to improve the output and quality of Yanhusuo.Corydalis yanhusuo W.T.Wang and other medicinal plants usually have continuous cropping obstacles,which reduces the yield of medicinal plants.Rhizosphere microorganisms and plants usually have symbiotic relationship and promote each other.The fine phosphorus and potassium solubilization in the rhizosphere of Corydalis yanhusuo W.T.Wang is beneficial to the growth and development of Corydalis yanhusuo W.T.Wang.After it is made into bio-bacterial fertilizer,it will alleviate the continuous cropping obstacle of Corydalis yanhusuo W.T.Wang and improve the yield and quality of Corydalis yanhusuo W.T.Wang.In this experiment,the rhizosphere soil of Corydalis yanhusuo W.T.Wang was collected from 4sites in several regions of Zhejiang and Chongqing,and it was isolated,purified and identified.The main results of this study are as follows:(1)In this experiment,79 strains of phosphorus and potassium solubilizing bacteria were isolated from the rhizosphere soil of Corydalis yanhusuo W.T.Wang in 4 regions by the dilution coating plate method.Among them,38 strains of organophosphorus bacteria,22 strains of inorganic phosphorus bacteria and 19 strains of potassium bacteria.Through physiological and biochemical tests,it was found that most of the 79 strains were grampositive bacteria,mainly Bacillus.In this experiment,the p H value of the fermentation broth of most strains decreased to varying degrees,which may be caused by the organic acid secreted by the strains in the process of phosphorus and potassium hydrolysis.Through the significant analysis of the amount and p H of phosphorus and potassium solubilization of each strain,it was found that there were significant differences in the capacity and p H of phosphorus and potassium solubilization of different strains.(2)According to the determination of the phosphorus solubilization ability of the organophosphorus solubilizing bacteria,the phosphorus increment of 38 strains of organophosphorus solubilizing bacteria was between 1.35 and 62.17 mg/L,and the phosphorus solubilization rate was between 0.27% and 12.41%,of which strain A26 had the largest phosphorus increment,62.17 mg/L.In addition to strain C17,38 strains of organophosphorus decomposing bacteria were all Bacillus.Combined with 16 S r DNA molecular sequencing and comparison results,as well as ten physiological and biochemical tests and Gram staining results,38 strains can be preliminarily identified as belonging to Bacillus subtilis,Bacillus amyloliquefaciens,Bacillus pustulosus,Bacillus paramyces and Bacillus cereus.The strain C17 is β Proteus.(3)Through 22 strains of inorganic phosphorus solubilizing bacteria,the amount of phosphorus increased ranged from 5.08 mg/L to 115.24 mg/L,and the rate of phosphorus solubilization ranged from 0.13% to 3.76%.The maximum amount of phosphorus increased by strain D3 was 115.24 mg/L.All 22 strains are Bacillus.Combined with the16 S r DNA molecular sequencing and comparison results,as well as the results of ten physiological and biochemical tests and Gram staining,22 strains of inorganic phosphorus solubilizing bacteria can be preliminarily identified as belonging to Bacillus Highland,Bacillus amyloliquefaciens,Bacillus pustulosus,Bacillus subtilis and Bacillus atrophic.(4)Among the 19 strains of potassium-dissolving bacteria,the content of available potassium in the fermentation broth is 2.08～5.06 mg/L,and the rate of potassium increase is 2.93%～150.86%.Among them,strain K1 has the strongest ability to dissolve phosphorus,and its fermentation broth content reaches 5.06 mg/L.According to the 16 S r DNA molecular sequencing comparison results and the results of ten physiological and biochemical tests and Gram staining,three strains of K2,K17,K21 among the 19 strains of potash solubilizing bacteria can be preliminarily identified as belonging to Agrobacterium rhizobia,and the remaining 16 strains belong to Bacillus subtilis,Bacillus besii,and Bacillus parcelli.The results showed that the dominant strains of phosphorus and potassium solubilizing bacteria in the rhizosphere soil of Corydalis yanhusuo W.T.Wang from different areas were different,and the ability of phosphorus and potassium solubilizing of the strains from different areas was also significantly different.During the fermentation and cultivation of the strain,the p H value of the fermentation broth of the strain decreased.It can be seen that organic acids will be produced to assist in the release of phosphorus and potassium during the decomposition of insoluble phosphorus and insoluble potassium by the phosphorus and potassium solubilizing bacteria.In the rhizosphere soil of Corydalis yanhusuo W.T.Wang,most of the strains with the ability of dissolving phosphorus and potassium are gram-positive bacteria,and most of the strains with high efficiency of dissolving phosphorus and potassium are bacillus.To sum up,the strains A26,D3 and K1 screened from the rhizosphere soil of Rhizoma Corydalis yanhusuo W.T.Wang are all Bacillus,and have the strongest ability of dissolving phosphorus and potassium,which can be used as the alternative strains for the development and utilization of corresponding biological fertilizer.