Semi-continuous detection of toxic hexavalent chromium using a sulfur-oxidizing bacteria biosensor.
Toxicity testing is becoming a useful tool for environmental risk assessment. A biosensor based on the metabolic properties of sulfur-oxidizing bacteria (SOB) has been applied for the detection of toxic chemicals in water. The methodology exploits the ability of SOB to oxidize elemental sulfur to sulfuric acid under aerobic conditions. The reaction results in an increase in electrical conductivity (EC) and a decrease in pH. Five hours after Cr(6+) was added to the SOB biosensor operated in semi-continuous mode (1 min rapid feeding and 29 min batch reaction), a decrease in effluent EC and an increase in pH (from 2-3 to 6) were detected due to Cr(6+) toxicity to SOB. The SOB biosensor is simple; it can detect toxic levels of Cr(6+) on the order of minutes to hours, a useful time scale for early warning detection systems designed to protect the environment from further degradation.
Kangwon National University, Gangwon-do, Chuncheon 200-701, South Korea.
Anup
A
Gurung
Sang-Eun
SE
Oh
Ki Duck
KD
Kim
Beom-Soo
BS
Shin
D001419:Bacteria / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D002857:Chromium / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013455:Sulfur / Q000378:metabolism; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D013455:Sulfur