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Isolation and characterization of a highly effective bacterium Bacillus cereus b-525k for hexavalent chromium detoxification.

ABSTRACT: The chromate resistant Gram-positive Bacillus cereus strain b-525k was isolated from tannery effluents, demonstrating optimal propagation at 37 °C and pH 8. The minimum inhibitory concentration (MIC) test showed that B. cereus b-525k can tolerate up to 32 mM Cr⁶⁺, and also exhibit the ability to resist other toxic metal ions including Pb²⁺ (23 mM), As³⁺ (21 mM), Zn²⁺ (17 mM), Cd²⁺ (5 mM), Cu²⁺ (2 mM), and Ni²⁺ (3 mM) with the resistance order as Cr ⁶⁺ > Pb²⁺ > As³⁺ >Zn²⁺ >Cd²⁺ >Ni²⁺ >Cu²⁺. B. cereus b-525k showed maximum biosorption efficiency (q) of 51 mM Cr⁶⁺/g after 6 days. Chromate stress elicited pronounced production of antioxidant enzymes such as catalase (CAT) 191%, glutathione transferase (GST) 192%, superoxide dismutase (SOD) 161%, peroxidase (POX) 199%, and ascorbate peroxidase (APOX) (154%). Within B. cereus b-525k, the influence of Cr⁶⁺ stress (2 mM) did stimulate rise in levels of GSH (907%) and non-protein thiols (541%) was measured as compared to the control (without any Cr⁶⁺ stress) which markedly nullifies Cr⁶⁺ generated oxidative stress. The pilot scale experiments utilizing original tannery effluent showed that B. cereus b-525k could remove 99% Cr⁶⁺ in 6 days, thus, it could be a potential candidate to reclaim the chromate contaminated sites.

SUBMITTER: Elahi A

PROVIDER: S-EPMC9073032 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature

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Isolation and characterization of a highly effective bacterium Bacillus cereus b-525k for hexavalent chromium detoxification.

Elahi Amina A Rehman Abdul A Zajif Hussain Syed S Zulfiqar Soumble S Shakoori Abdul Rauf AR

Saudi journal of biological sciences 20220113 4

The chromate resistant Gram-positive Bacillus cereus strain b-525k was isolated from tannery effluents, demonstrating optimal propagation at 37 °C and pH 8. The minimum inhibitory concentration (MIC) test showed that B. cereus b-525k can tolerate up to 32 mM Cr6+, and also exhibit the ability to resist other toxic metal ions including Pb2+ (23 mM), As3+ (21 mM), Zn2+ (17 mM), Cd2+ (5 mM), Cu2+ (2 mM), and Ni2+</ ...[more]

PMID: 35531181

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Dataset Information

Isolation and characterization of a highly effective bacterium Bacillus cereus b-525k for hexavalent chromium detoxification.

Publications

Isolation and characterization of a highly effective bacterium <i>Bacillus cereus</i> b-525k for hexavalent chromium detoxification.

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