一株高效解磷菌的筛选鉴定及溶磷性能

【背景】土壤中大部分磷元素是以难溶性磷酸盐的形式存在，不能被农作物有效利用，而传统化学肥料会带来环境污染等问题。【目的】解决土壤磷缺失现状，开发新型、安全、高效的微生物菌肥。【方法】取武汉科技大学图书馆后土壤为试验材料，筛选出一株高效解磷菌。通过个体形态鉴定、生理生化鉴定、16S rRNA基因序列分析鉴定菌株，以NBRIP为基础培养基进行条件优化，借助高效液相色谱进行细菌解磷机理探究。【结果】所筛选的高效解磷菌株为唐菖蒲伯克霍尔德氏菌(Burkholderia gladioli)。在20种氨基酸中，D-蛋氨酸对菌株的生长和溶磷促进作用最好，促进效果达到19.09%和16.16%，甲酸钠对菌株的生长和溶磷有抑制效果，抑制效果达到39.08%和10.66%。该菌株通过分泌葡萄糖醛酸、D-L-苹果酸等有机酸溶解环境中的磷酸盐，将菌株制作成菌肥对辣椒幼苗有明显的促生长作用。【结论】利用唐菖蒲伯克霍尔德氏菌(Burkholderia gladioli)分泌有机酸溶解土壤中的磷酸盐，可为生物肥料的制备和应用提供一定的理论参考。

Isolation, identification, and characterization of a phosphate-solubilizing bacterial strain

Background] Most of the phosphorus in the soil exists in the form of insoluble phosphate, which is unavailable to crops, and traditional chemical fertilizer causes environmental pollution. Objective] To tackle soil phosphorus deficiency and develop a safe and efficient microbial fertilizer. Methods] An efficient phosphate-solubilizing bacterial strain was screened out from the soil behind the library of Wuhan University of Science and Technology and identified by morphological observation, determination of physiological and biochemical indexes, and 16S rRNA gene sequencing. The phosphate-solubilizing conditions were optimized based on NBRIP medium, and the phosphorus-solubilizing mechanism was explored by high performance liquid chromatography. Results] The strain was identified as Burkholderia gladioli. Among the 20 amino acids, D-methionine was prominent in promoting the growth and phosphate solubilization of the strain, improving the growth and solubilized phosphate by 19.09% and 16.16%, respectively. Sodium formate inhibited the growth and phosphorus dissolution of the strain, with the inhibition rate of 39.08% and 10.66%, respectively. The strain dissolved phosphate in the environment by secreting organic acids such as glucuronic acid and D-L-malic acid. The fertilizer prepared with the strain could significantly promote the growth of pepper seedlings. Conclusion] B. gladioli secretes organic acids to dissolve phosphate in the soil, which lays a theoretical basis for the preparation and application of biological fertilizer.