| In this study,by analyzing the physical and chemical properties of different saline lake soils,the optimum separation conditions were designed and the actinomycetes were isolated and purified.Meanwhile,the obtained strains were analyzed by cluster analysis and halophilic salt tolerance rules.The results showed that:1.The salt contents of every salt lake was high,and between 44.48131.87 g/kg;the main ions were Na+and Cl-.The soil samples pH were between 8.649.31,which were basicity or strong basicity.The content of nutrients was low in gerenal.There were some correlations between soil physical and chemical factors,and soil salinity had the greatest influence on soil physical and chemical properties.2.This study investigated the effects of pretreatment of samples,mediums design,salt types and concentrations design on theisolation effects of actinomycetes.The results showed that the number of actinomycetes was the highest in the samples treated with spore activator（YE 6%+SDS 0.05%）;separation efficiency was highest when a medium with a5%original mineral salt concentration was used to isolate actinomyces;the quantities of actinomycetes was the most under F6 medium in each salt concentration.3.By 16S rDNA cluster analysis,45 representative strains were distributed in 8genera,respectively Saccharopolyspora,Prauserella,Streptomyces,Amycolatopsis,Nocar-diopsis,Gracilibacillus,Bacillus and Staphylococcas.The dominant population were Saccharopolyspora,Prauserella and Bacillus.4.The salt tolerance test showed that the levels of halophilic bacteria were above mild,and they were selective for different salt ions;Most of the bacteria to Na+,Mg2+had a broadder range of adaptations,and the selectivity to Ca2+was stronger.The adaptation range of some strains to Mg2+exceeded Na+and complex salt.The above results show that the resource of actinomycetes is extremely rich in Tsaidam-Ma Hai boron rich Saline Lake area,which is worth studying deeply. |
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