关键词: 根际菌, 铁载体, 生物强化策略, 土壤硒

Abstract: The present study focused on revealing the correlation between the siderophore production by siderophore-producing rhizobacteria (SPR) and selenium (Se) bioavailability in the soils by isolating, identifying and assessing on Se biofortification of SPR. Siderophore-producing bacteria were isolated and quantitative detected using chrome azural S (CAS) plate method from Guizhou Kaiyang maize rhizosphere soils. The capacity of indoleacetic acid (IAA) was detected using Salkowski colorimetry, and the identification was taken by 16S rRNA gene sequence analysis. Moreover, the Se activation test of strains in soils were carried out in lab plates. The results showed that the 5 strains had strong siderophore production ability, among which the siderophore activity unit of WD06 reached up to 73%. All strains had a certain capacity of IAA production. Furthermore, all strains could improve the water-soluble Se contents with 2.50 to 7.85 times and the available Se contents with 0.46 to 4.72 times. Identification on the three best performance strains revealed that WD01 as Klebsiella michiganensis, WD06 as Serratia marcescens and WD07 as Enterobacter xiangfangensis. The present results were helpful for soil Se biofortification via microbial strategy.

Key words: rhizobacteria, siderophore, biofortification strategy, soil selenium