Cyanide Detoxification in Gold Mining-Impacted Aquatic Ecosystems

Research at Afe Babalola University has uncovered crucial information about the enzyme rhodanese, which plays a vital role in detoxifying cyanide in aquatic ecosystems affected by gold mining. The study demonstrated the enzyme's ability to neutralize cyanide, a toxic substance released by gold extraction processes. The findings have significant implications for the development of bioremediation strategies to restore polluted aquatic ecosystems.

Key Takeaways:

• The study examined liver rhodanese from Coptodon zillii, a fish species affected by gold mining in Nigeria.
• The enzyme was purified and characterized, revealing a specific activity of 5.4 U/mg and a molecular weight of 36 kDa.
• The optimal pH and temperature for enzymatic activity were determined to be 8.0 and 50°C, respectively.
• The enzyme exhibited Michaelis-Menten kinetics with a Km of 20.0 mM for sodium thiosulfate and 25.0 mM for potassium cyanide.
• The enzyme showed a preference for thiosulfate utilization and formed hydrogen bonds with thiosulfate.
• The findings demonstrate the enzyme's potential for cyanide detoxification and importance in restoring polluted aquatic ecosystems.

Statistics:

• The specific activity of the purified enzyme was 5.4 U/mg.
• The molecular weight of the native enzyme was 36 kDa, comprising 17 kDa subunits.
• The enzyme's optimal pH and temperature for activity were 8.0 and 50°C, respectively.
• The Km values for sodium thiosulfate and potassium cyanide were 20.0 mM and 25.0 mM, respectively.
• The enzyme showed a preference for thiosulfate utilization.

Sources:

• Oluwaseun E. Agboola, Zainab A. Ayinla, et al. Structural and Kinetic Properties of Liver Rhodanese from Coptodon zillii: Implications for Cyanide Detoxification in Gold Mining-Impacted Aquatic Ecosystems. Toxics, 2025,13(9), 750. https://doi.org/10.3390/toxics13090750.
• Afe Babalola University, Institute of Drug Research and Development.