Fig. 9.

Proposed Cd²⁺ biosorption and resistance mechanism in gram negative bacterium, S. enterica 43C. (1) Peptidoglycan is the primary site on bacterial surface that binds Cd²⁺ in monolayer. (2) Cd²⁺ enter the cells via metal ions transport channel proteins and are known to cause oxidative stress which is combated by GSH dependent antioxidant system. (3) Metallothioneins, induced by Cd²⁺ stress, are primarily involved in Cd²⁺ sequestration through their thiols groups thus mitigating Cd²⁺ interference with cellular metabolism