title: Development of an online sulfur-oxidizing bacteria biosensor for the monitoring of water toxicity.
abstract: A toxicity monitoring system based on the metabolic properties of sulfur-oxidizing bacteria (SOB) in continuous and fed-batch modes has been applied for the detection of nitrite (NO2 (-)-N). In this study, the effects of different concentrations of NO2 (-)-N (0.1 to 5 mg/L) on the SOB bioreactors were tested. We found that 5 mg/L NO2 (-)-N was very toxic to the SOB bioreactors in both continuous (R1) and fed-batch (R2) modes, showing complete inhibition of SOB activity within 2 h of operation. R1 and R2 were operated in different ways; however, the EC inhibition and recovery patterns were very similar. The EC rate increased with an increasing NO2 (-)-N concentration in both continuous and fed-batch modes. The addition of 5 mg/L NO2 (-)-N in continuous mode decreased the average EC rate by 14.38 ± 2.1 μS/cm/min; while in fed-batch mode, the EC rate decreased by 23 μS/cm/min. Although the toxicity monitoring system could detect 0.5-5 mg/L NO2 (-)-N, it could not detect 0.1 mg/L NO2 (-)-N in either continuous or fed-batch operation. Thus, the SOB biosensor method presented is useful to detect toxic agents such as NO2 (-)-N within a few minutes or hours.
authors.affiliation: Department of Biological Environment, Kangwon National University, 192-1 Hyoja-2-dong, Gangwon-do, Chuncheon, 200-701, South Korea.
authors.forename: Anup
authors.initials: A
authors.lastname: Gurung
authors.forename: Woo-Chang
authors.initials: WC
authors.lastname: Kang
authors.forename: Beom-Soo
authors.initials: BS
authors.lastname: Shin
authors.forename: Ju Sik
authors.initials: JS
authors.lastname: Cho
authors.forename: Sang-Eun
authors.initials: SE
authors.lastname: Oh
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D015374:Biosensing Techniques / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D009573:Nitrites; D010084:Oxidation-Reduction; D013455:Sulfur / Q000378:metabolism*; D014877:Water Pollution, Chemical
chemical_list: D009573:Nitrites; D013455:Sulfur