Effect of heavy metals on growth response and antioxidant defense protection in Bacillus cereus
2014
Behera, Madhumita | Dandapat, Jagneshwar | Rath, Chandi Charan
Bacterial cells in aerobic environment generate reactive oxygen species which may lead to oxidative stress, induced by a wide range of environmental factors including heavy metals. In the present context an attempt has been made to determine the toxic impact of cadmium and copper on growth performance, oxidative stress, and relative level of antioxidant protection in Bacillus cereus. Outcome of this study suggests that both the metal ions depleted the growth rate in this organism with respect to time and concentration of the metal ions. CdCl₂exposure induced extracellular glutathione (GSH) production, whereas, its level was declined in response to CuSO₄.Superoxide dismutase (SOD) activity and hydrogen peroxide (H₂O₂) content was elevated under CdCl₂stress but the activity of catalase (CAT) was inhibited. In contrast, incubation of bacteria with CuSO₄exhibited decreased SOD activity with concomitant rise in CAT activity and H₂O₂content. We also observed elevation of intracellular GSH level in this bacteria following supplementation of N‐acetyl cysteine (NAC) in the medium. Overall findings of this study indicated differential toxicity of CdCl₂and CuSO₄in inducing oxidative stress, depleting growth rate and the possible involvement of GSH and CAT in adaptive antioxidant response.
显示更多 [+] 显示较少 [-]