Toxicity screening of Escherichia coli NCIB 9484 and Bacillus subtilis 007, NCIB 168 and NCIB 1650 has shown Cs+ to be the most toxic Group 1 metal cation. However, toxicity and accumulation of Cs+ by the bacteria was affected by two main external factors; pH and the presence of other monovalent cations, particularly K+. Over the pH range 6-9 both E. coli and B. subtilis showed increasing sensitivity towards caesium as the pH was raised. The presence of K+ and Na+ in the laboratory media used lowered caesium toxicity and lowered acumulation of the metal. In order to assess accurately Cs+ toxicity towards the bacterial strains it was therefore necessary to define the K+:Cs+ ratio in the external medium. The minimum inhibitory K+:Cs+ concentration ratio for the Bacillus strains tested was in the range 1:2-1:3 while E. coli had a minimum inhibitory K+:Cs+ concentration ratio of 1:6.
|Number of pages||8|
|Journal||Journal of Industrial Microbiology|
|Publication status||Published - 1 Mar 1995|
- Bacillus subtilis
- Escherichia coli
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology