Separating and screening method for siderophilic phosphorite-dissolving bacterium

Abstract

The invention discloses a separating and screening method for a siderophilic phosphorite-dissolving bacterium. The method comprises the following steps: (1) collecting rhizosphere soil of crops, removing impurities, inoculating sterile water with the rhizosphere soil, culturing for 2-3 hours at 25-35 DEG C and separating supernate; (2) preparing a CAS-P detection flat panel, uniformly mixing a CaCl2 solution, a MgSO4.7H2O solution, and an acid hydrolyzed casein solution with the mass concentration of 8-12%, adding Ca3(PO4)2 into the mixture, adjusting the pH to 6.8-7.0 and fixing the volume by means of water; adding agar powder, sterilizing, and further adding CAS blue detection liquid when the temperature is reduced to 50-60 DEG C after sterilization, uniformly mixing and pouring on the flat panel; and (3) inoculating the CAS-P detection flat panel with the supernate obtained in the step (1), wherein the inoculum size is 100-200 microliter / flat panel, culturing for 3-5 days at 25-35 DEG C, wherein the strain growing on the detection flat panel is the siderophilic phosphorite-dissolving bacterium. By adopting the screening method disclosed by the invention, the separating and screening steps are simplified, the screening time is greatly shortened, and the separating and screening efficiency of the siderophilic phosphorite-dissolving bacterium is improved.

Description

technical field [0001] The invention relates to a method for separating and screening iron-loving phospholytic bacteria. Background technique [0002] Iron is one of the trace elements necessary for most organisms. Although the content of iron elements in the earth's crust occupies the fourth place, most of them cannot be directly used by plants, and a set of efficient iron transport mechanisms are needed to obtain the iron ions they need. In a low-iron environment, most bacteria can synthesize and secrete siderophiles for use by themselves and plants to promote plant growth; and by competing with pathogenic microorganisms for limited iron nutrition, they can inhibit the growth and reproduction of pathogenic microorganisms and play a role in biological control role. [0003] Phosphorus is one of the indispensable nutrient elements for plant growth. Although a large amount of soluble phosphorus fertilizer is applied to the soil every year, the phosphate in the soil is often ...

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Problems solved by technology

[0003] Phosphorus is one of the indispensable nutrient elements for plant growth. Although a large amount of soluble phosphorus fertilizer is applied to the soil every year, the phosphate in the soil is often mainly tricalcium phosphate. This kind of phosphate has poor solubility and is difficult to be absorbed by plants. , the utilization rate of phosphorus fertilizer by crops in the current season is generally only 5% to 10%, and the aftereffect of crops is added, and the utilization rate does not exceed 25%.

Separation and screening of microbial strains with high-efficiency phosphorus-dissolving effect and making micro-fertilizers is an effective method to solve the low utilization rate of phosphorus fertilizers and control the environmental pollution caused by the abuse of fertilizers

[0004] For the screening of plant growth-promoting rhizobacteria (Plant Growth-Promoting Rhizobacteria, referred to as PGPR) with iron-loving or / and phosphate-solubilizing ability, and used in agricultural production to solve the problems of plant iron deficiency yellowing and low utilization rate of phosphate fertilizer, there have been some related reports

However, in the existing technology, siderophilic bacteria and phosphate-dissolving bacteria are screened separately. Even if some strains have multiple disease prevention and growth promotion mechanisms such as siderophilia and phosphate-dissolving ability, their siderophilic ability or phosphate-dissolving ability are detected separately, and the steps are complicated. , the screening efficiency is low, time-consuming and labor-intensive

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