Characterization of exopolymeric substances from selected Rhodopseudomonas palustris strains and their ability to adsorb sodium ions

Tomorn Nunkaew; Duangporn Kantachote; Teruhiko Nitoda; Hiroshi Kanzaki; Raymond J Ritchie

doi:10.1016/j.carbpol.2014.08.099

Characterization of exopolymeric substances from selected Rhodopseudomonas palustris strains and their ability to adsorb sodium ions

Carbohydr Polym. 2015 Jan 22:115:334-41. doi: 10.1016/j.carbpol.2014.08.099. Epub 2014 Sep 15.

Authors

Tomorn Nunkaew¹, Duangporn Kantachote², Teruhiko Nitoda³, Hiroshi Kanzaki⁴, Raymond J Ritchie⁵

Affiliations

¹ Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand. Electronic address: tomorn.n@gmail.com.
² 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.
³ 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.
⁴ 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.
⁵ Faculty of Technology and Environment, Prince of Songkla University, Phuket 83120, Thailand. Electronic address: raymond.r@phuket.psu.ac.th.

PMID: 25439902
DOI: 10.1016/j.carbpol.2014.08.099

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.

Keywords: Biofertilizers; Exopolymeric substances; Galacturonic acid; Rhodopseudomonas palustris; Rice; Salinity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Biopolymers / chemistry*
Rhodopseudomonas / chemistry*
Rhodopseudomonas / drug effects
Rhodopseudomonas / physiology
Sodium Chloride / chemistry*
Sodium Chloride / pharmacology
Stress, Physiological / drug effects

Substances

Biopolymers
Sodium Chloride