Molecular Characterization of Salt-Tolerant Bacteria Isolated from Greenhouse Vegetable Cultivation Soils

摘要

The aim of this study was to isolate salt-tolerant bacteria (STB) and identify their molecular properties from greenhouse vegetable cultivation soils in Shou county, China. The STB comprised 21?31% of the total viable cell count. A total of 12 strains were isolated from greenhouse saline soil and were classified as STB. All the isolates were Gram positive. Most of the isolates displayed plant growth-promoting trait, such as indole production. The majority of STB was positive for oxidase. Although the number of STB was only a third of the total viable cells, BOX-PCR and ERIC-PCR DNA fingerprinting showed different cluster groups, suggesting that the diversity of salt resistance bacterial isolates colonizing greenhouse soils differed. All the 12 sequenced isolates belonged to the cluster of Bacillus sp., which means that this genus is dominant in greenhouse soils. Only Bacillus sp. exhibited a strong ability to adapt in greenhouse saline soils. It was presumed that accumulation of salt ions and decreased pH value in the greenhouse soils could increase the osmotic pressure, which directly affected the number of bacteria with salt resistance. However, the obtained salt tolerant isolates should be further investigated for their application to sustainable agriculture.