| Phosphorus tailings and sauce-flavor liquor lees belong to the bulk solid waste of the phosphorous chemical industry and liquor industry in Guizhou.Due to the problems of large output and serious environmental pollution,it is urgent to develop a set of key technologies for sustainable development.Combining the two into phosphorus-containing fertilizers is a new way to achieve high value for low-cost waste.In order to promote the promotion and utilization of this technology,exogenous phosphate-solubilizing microorganisms are added to the composting process to solve the problems of long composting fermentation cycle and low phosphorus content in products.However,phosphate-solubilizing microorganisms which are separated and screened under normal temperature cannot survive 5?10 days in a high-temperature composting environment above 50?,so it is urgent to develop phosphate-solubilizing microorganisms that can withstand high temperature conditions.Based on this,this study will focus on the screening of high-temperature resistant inorganic phosphorus microorganisms and their phosphate-solubilizing characteristics,through the single factor and response surface test to determine the optimal ratio of phosphate-solubilizing microorganism culture medium,using high-performance liquid chromatography technology(HPLC)and transcriptomics technology carried out a preliminary study on the mechanism of pyrolysis of pyrolysis-resistant inorganic phosphorus bacteria from the perspective of metabolites and molecular biology.This study provides the theoretical basis and technical support for promoting the application of high temperature resistant phosphate-solubilizing microorganisms,meanwhile,it has important practical significance for improving the application value of phosphorus-resolving microorganisms.The main conclusions are as follows:1.In the experiment,the aerobic composting of phosphate tailings powder and sauce-flavored liquor lees sampled by the research team in the early stage was used as the research object,and two thermo-tolerant phosphate-solubilizing bacterias and three thermo-tolerant phosphate-solubilizing fungi were isolated and purified from thesample,which were identified as Bacillus subtilis,Bacillus licheniformis,Lichtheimia ramosa,Aspergillus fumigatus,and Aspergillus nidulans.2.Placed the 5 high-temperature-resistant phosphate-solubilizing microorganisms in the inorganic phosphorus liquid medium with tricalcium phosphate as the only phosphorus source,and incubated at a constant temperature of 50? for 7days to study the characteristics of each high-temperature resistant phosphate-solubilizing microorganisms phosphate-solubilizing ability.The results of the study found that there were obvious differences in the phosphate-solubilizing ability of different strains.The maximum phosphate-solubilizing amounts of GDB1,GDB2,GDF1,GDF2 and GDF3 were 145.13 mg/L,159.44 mg/L,174.33 mg/L and158.90 mg/L And 136.85 mg/L.Among them,the research of GDF1 on the solution of inorganic phosphorus is the first report,which has great research value.3.The single-factor test and response surface test were used to optimize the phosphate-solubilizing conditions of strain GDF1.The results showed that the best phosphate-solubilizing conditions for the high-temperature-resistant strain GDF1were: sucrose 10.65 g/L,ammonium oxalate 0.61 g/L,inorganic salts 1.02 g/L,and tricalcium phosphate 10.70 g/L.Under this condition,its solubilizing amount of tricalcium phosphate could reach 292.59 mg/L.The model predicted the dissolved phosphorus amount of 291.35 mg/L,and the actual verified dissolved phosphorus amount was 292.59 mg/L.This experiment proved that after optimization,GDF1 performed a good phosphate-solubilizing ability in the high-temperature-resistant phosphate-solubilizing fungi,and can be used as a potential raw material for high-temperature-resistant microbial preparations.4.The single-factor test and response surface test were used to optimize the phosphate-solubilizing conditions of strain GDB2..The results showed that the best phosphate-solubilizing conditions for the high-temperature-resistant strain GDB2were: glucose 23.16 g/L ammonium sulfate 0.78 g/L,inorganic salt 1.92 g/L,and tricalcium phosphate 9.91 g/L.Under this condition,its solubilizing amount of tricalcium phosphate could reach 328.21 mg/L.and the actual verified dissolved phosphorus amount was 327.53 mg/L.This experiment proved that after optimization,GDB2 performed a good phosphate-solubilizing ability in the high-temperature-resistant phosphate-solubilizing bacteria,and can be used as a potential raw material for high-temperature-resistant microbial preparations.5.In this study,HPLC was used to qualitatively and quantitatively analyze theorganic acids in the liquid fermentation medium optimized by the high-temperature-resistant phosphate-solubilizing fungus GDF1.As a result,a total of five organic acid ingredients was detected in the GDF1 fermentation broth which were tartaric acid,oxalic acid,acetic acid,and 2 unknown acids.Among these organic acid which tartaric acid has the highest content of 33.37 mg/L,oxalic acid has the lowest content of only 5.34 mg/L,and acetic acid content of 10.77 mg/L.6.In this study,BFM GDF1 grown in basic fermentation culture was used as a control group,and OFM GDF1 grown in optimized fermentation medium was used as an experimental group for transcriptome sequencing and analysis.Transcriptome comparative analysis found that there were 1993 differentially expressed genes between the two sample groups,of which 786 genes were up-regulated and 1207 genes were down-regulated.The significantly enriched pathways in the differential gene KEGG metabolic pathway mainly include the Biosynthesis of unsaturated fatty acids,fatty acid degradation,peroxisomes,?-linolenic acid metabolism,glutathione metabolism,glyceride metabolism,glycolysis/sugar Xenobiosis etc.The above results laid the foundation for further research on the molecular mechanism of the degradation of poorly soluble phosphorus by the high-temperature-resistant phosphate-solubilizing fungus GDF1. |
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