title: Characterization of exopolymeric substances from selected Rhodopseudomonas palustris strains and their ability to adsorb sodium ions.
abstract: Removal of Na(+) by binding with exopolymeric substances (EPS) from Rhodopseudomonas palustris TN114 and PP803 was investigated. The moderate negative correlation pairs (rp) between remaining Alcian blue and amount of Na(+) adsorbed on EPS from strains TN114 and PP803 were -0.652 and -0.609. Both strains showed positive relationships between the amounts of EPS produced and bacterial growth. EPS from strain PP803 had a higher efficiency in removing Na(+) than the EPS from strain TN114 based on their EC50 values (1.79 and 1.49 mg/mL for TN114 and PP803, respectively). The principal component from EPS of strain PP803 which was responsible for salt removal was purified and it was identified as a polysaccharide (≈18 kDa) mainly composed of galacturonic acid. Overall results suggested that EPS is a key factor that our strains used to bind Na(+) allowing their survival in high NaCl concentrations.
authors.affiliation: Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand. Electronic address: tomorn.n@gmail.com.
authors.forename: Tomorn
authors.initials: T
authors.lastname: Nunkaew
authors.affiliation: Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Hat Yai, Thailand. Electronic address: duangporn.k@psu.ac.th.
authors.forename: Duangporn
authors.initials: D
authors.lastname: Kantachote
authors.affiliation: Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-Ku, Okayama 700-8530, Japan. Electronic address: nitoda@cc.okayama-u.ac.jp.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Nitoda
authors.affiliation: Graduate School of Environmental and Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-Ku, Okayama 700-8530, Japan. Electronic address: hkanzaki@cc.okayama-u.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kanzaki
authors.affiliation: Faculty of Technology and Environment, Prince of Songkla University, Phuket 83120, Thailand. Electronic address: raymond.r@phuket.psu.ac.th.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Ritchie
mesh_terms: D000327:Adsorption; D001704:Biopolymers / Q000737:chemistry*; D012241:Rhodopseudomonas / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D012965:Sodium Chloride / Q000737:chemistry* / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D001704:Biopolymers; D012965:Sodium Chloride
keywords: Biofertilizers; Exopolymeric substances; Galacturonic acid; Rhodopseudomonas palustris; Rice; Salinity