Screening And Identification Of Local Soil Phosphorus And Potassium Bacteria In Daliuta Mining Area

The development and utilization of coal resources has greatly promoted the rapid development of the regional economy,but at the same time it has also caused serious ecological and environmental problems.Underground mining resulted in the formation of underground goafs.The subsidence of the gobs destroyed the integrity of the soil structure,which in turn led to the leakage of surface water and a drop in the groundwater level,which exacerbated desertification,salinization,and depletion of the mining area.Land remediation and ecological restoration in mining subsidence areas is one of the major issues for restoration biology.As a key part of the material cycle process,soil microorganisms play an important role in improving soil properties,soil fertility,and promoting nutrient supply in the subsidence area.The ecological restoration of coal mining subsidence areas cannot be separated from the participation of microorganisms.In order to obtain active bacterial strains with potential for application and good environmental compatibility,we used the selective medium for the isolation and screening of soil microorganisms in the soil in the Daliuta mining area of Shenmu County,Shanxi Province.Routine test methods were used to determine the ability of dissolve phosphorus and potassium of the strains,and strains with strong decomposition ability were selected.The strains were identified according to their morphological characteristics,physiological characteristics and 16 SrDNA sequence analysis.The main results are as follows:1.21 strains of phosphate-solubilizing bacteria and 4 strains of potassium bacteria were initially screened.Morphological observation showed that the colony morphology of the phosphate-solubilizing bacteria was round and opaque,smooth and moist,with protrusions,and the color was yellowish;the colony morphology of the potassium bacteria was round and transparent,moist and smooth,and the edges were neat and relatively viscous.Gram stain results were negative for all strains.2.Among the 15 strains obtained by rescreening,the CW01-2,CW01-5 and CW01-9 strains had the highest organophosphorus activities,46.32?g/mL ?45.17?g/mL and 45.49?g/mL,respectively.The potassium release rates of K-9,K-10,and K-11 were 4.49mg/kg?7.84mg/kg and 7.05mg/kg,respectively.3.Phosphate-solubilizing bacteria can use sucrose,maltose?glycerol and glucose as carbon sources,and all potassium bacteria can use sucrose and glycerol as carbon sources.Phosphate-solubilizing bacteria CW01-2,CW01-5,CW01-9,WC23-14,and WC23-30 can both grow on the medium containing nitrate and ammonium as their nitrogen source.The potassium bacteria K-5 and K-11 can use nitrate nitrogen,K-10 uses ammonium salt as nitrogen source,K-9 can use nitrate nitrogen and ammonium salt as nitrogen source,has certain nitrogen fixation ability,and can grow on medium with pH 7-11 and NaCl content of 3%,indicating a certain degree of salt and alkali resistance.4.The 16 SrDNA sequence method was used to identify the strains.The phospholysis bacteria were Pseudomonas sp.and the potassium were Paenibacillus.By constructing a phylogenetic tree,Pseudomonas putida strain,Pseudomonas koreensis strain,and Pseudomonas fluorescens strain have the closest genetic evolutionary distances,all of which are highly homologous to Pseudomonas sp.5.The phosphate solubilizing bacteria and potassium solubilizing bacteria have a certain ability of dissolve phosphorus and potassium,have certain nitrogen fixing ability,good salt alkali resistance and strong resistance,and can be used as an effective reserve strain for reclaimed mining area.