Isolation and characterization of halotolerant phosphate solubilizing bacteria naturally colonizing the peanut rhizosphere in salt-affected soil

Abstract

In search of efficient salt-tolerant phosphate solubilizing bacteria (PSB), we conducted a survey of PSB that naturally colonize the rhizosphere of peanuts in Xinjiang, China, a typical inland saline area. A total of 23 PSB were isolated, which included 12 Bacillus strains, three Acinetobacter strains, two Pseudomonas strains, two Brevibacillus, and one strain of Gordonia terrae, Chryseobacterium lathyri, Ensifer sesbaniae, and Paenibacillus illinoisensis. All PSB have high potential for dissolving calcium phosphate [Ca₃(PO₄)₂] within the range of 65–496 mg·L⁻¹, but relatively weak ability to dissolve AlPO₄ in amounts ranging from 0.4 to 11.4 mg·L⁻¹, FePO₄ ranging from 0.1 to 5.5 mg·L⁻¹, and lecithin ranging from 2.1 to 10.3 mg·L⁻¹. The maximum tolerance for pH is 10, and the maximum tolerance for Na₂CO₃ is 50 mm. Six isolates that can grow under the condition of 1.5 M NaCl (YMX5, YMX11, TPMX5, TPMX16, TPMX18, and TPMX19) were selected to determine their ability to dissolve Ca₃(PO₄)₂ and tolerate pH changes. This study characterized salt-tolerant PSB isolates that can be used as bioinoculants to protect plants against salt stress. In addition, we describe the phosphate-solubilizing ability of Gordonia terrae at high NaCl concentrations.

Keywords:

• peanut
• Salt-affected soil
• phosphate solubilizing bacteria
• salt tolerance

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Disclosure statement

No conflict of interest was declared.

Additional information

Funding

This study was supported by grants from the Taishan Scholar Project Funding, National Ten Thousand Youth Talents Plan of 2014 [W02070268], the China Agriculture Research System [CARS-13 to XC], the National Natural Science Foundation of China [31701464], the Natural Science Fund of Shandong Province [ZR2016CM07; ZR2017YL017], the Youth Scientific Research Foundation of Shandong Academy of Agricultural Sciences [2016YQN14], Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences [CXGC2016B02], Young Talents Training Program of Shandong Academy of Agricultural Sciences, and the Basic Research Project of Qingdao [17-1-1-51-jch].