alexa Cadmium biosorption by a cadmium resistant strain of Bacillus thuringiensis: regulation and optimization of cell surface affinity for metal cations.
Environmental Sciences

Environmental Sciences

Journal of Bioremediation & Biodegradation

Author(s): ElHelow ER, Sabry SA, Amer RM

Abstract Share this page

Abstract A marine bacterial strain putatively identified as Bacillus thuringiensis strain DM55, showed multiple heavy metal resistance and biosorption phenotypes. Electron microscopic studies revealed that DM55 cells are encased in anionic cell wall polymers that can immobilize discrete aggregates of cations. Factors affecting cell surface affinity for metal cations, monitored by means of Cd2+ binding capability, are investigated. The mechanisms of cadmium resistance and Cd2+ biosorption by the bacterium appeared to be inducible and coincident. Medium components affecting metal removal under cadmium-stressed growth conditions were explored based on the application of two sequential multi-factorial statistical designs. Concentrations of potassium phosphates and peptone were the most significant variables. Optimized culture conditions allowed DM55 cells grown in the presence of 0.25 mM CdCl2 to remove about 79\% of the metal ions within 24 h with a specific biosorption capacity of 21.57 mg g(-1) of biomass. Both fresh and dry cells of DM55 prepared under cadmium-free optimal nutrient condition were also able to biosorb Cd2+. In addition to the concentration of phosphate in the medium, KinA, a major phosphate provider in the phosphorelay of Bacillus cells, was also demonstrated to regulate the magnitude of cell surface affinity for cadmium ions.
This article was published in Biometals and referenced in Journal of Bioremediation & Biodegradation

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 6th World Congress on Biofuels and Bioenergy
    Sep 5-6, 2017 London, UK
  • 6th World Congress on Biopolymers
    September 7-9, 2017 Paris, France
  • 7th International Conference and Exhibition on Biopolymers and Bioplastics
    October 19-21, 2017 San Francisco, USA
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version