Isolation and characterization of Acidithiobacillus caldus from a sulfur-oxidizing bacterial biosensor and its role in detection of toxic chemicals

Sedky H.A. Hassan, Steven W. Van Ginkel, Sung Min Kim, Sung Hwan Yoon, Jin Ho Joo, Beom Soo Shin, Byong Hun Jeon, Wookeun Bae, Sang Eun Oh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


A novel toxicity detection methodology based on sulfur-oxidizing bacteria (SOB) has been developed for the rapid and reliable detection of toxic chemicals in water. The methodology exploits the ability of SOB to oxidize sulfur particles in the presence of oxygen to produce sulfuric acid. The reaction results in an increase in electrical conductivity (EC) and a decrease in pH. The assay is based on the inhibition of SOB in the presence of toxic chemicals by measuring changes in EC and pH. We found that SOB biosensor can detect toxic chemicals, such as heavy metals and CN-, in the 5-2000. ppb range. One bacterium was isolated from an SOB biosensor and the 16S rRNA gene of the bacterial strain has 99% and 96% sequence similarity to Acidithiobacillus sp. ORCS6 and Acidithiobacillus caldus DSM 8584, respectively. The isolate was identified as A. caldus SMK. The SOB biosensor is ideally suited for monitoring toxic chemicals in water having the advantages of high sensitivity and quick detection.

Original languageEnglish
Pages (from-to)151-155
Number of pages5
JournalJournal of Microbiological Methods
Issue number2
Publication statusPublished - Aug 2010
Externally publishedYes


  • Acidithiobacillus
  • Biosensor
  • Monitoring
  • Sulfur-oxidizing bacteria
  • Toxicity

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Microbiology (medical)

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