Isolation and characterization of novel Rhodobacter spp. with the sodium removal ability from mangrove forest sediment in Southeast Vietnam

Salt contamination is one of the major problems of agricultural land. It is important to find new bacteria with sodium removal ability, which can be used to reduce salts from soils. This study aims to isolate and characterize the novel Rhodobacter spp. with the sodium removal ability from mangrove forest sediment in Southeast Vietnam. After screening of morphological characteristics of the cell size, shape, and presence of protrusions, seven strains were identified. The results also showed that these strains were able to reduce NaCl from Glutamate-malate medium (GM). The concentration of NaCl decreased from 28.57% to 36.42% for the treatment with 25 ppm NaCl after 14 days of incubation. However, in the 35ppm NaCl concentration was absorb proficiency of decrease by approximately 5% compare with the 25 ppm NaCl concentration. The gene sequences of the 16S rDNA and puMf gene regions of the isolated strains shared high similarities with genus Rhodobacter, which were identified as Rhodobacter sphaeroides and Rhodobacter johrii. Our results showed a high diversity in the isolated strains belonging to the Rhodobacter species with sodium absorption ability. This study suggests the possibility of using isolated Rhodobacter strains to remove salinity from soils.