Use of Walnut Shell Powder to Inhibit Expression of Fe2+-Oxidizing Genes of Acidithiobacillus Ferrooxidans

International Journal of Environmental Research and Public Health

Yuhui Li¹  Yifeng Zhang¹  Huifang Tan¹  Mei Yue¹  Yehao Liu² 

[1] Department of Biological and Environmental Engineering, Hefei University, Hefei 230601, China;School of Public Health, Anhui Medical University, Hefei 230032, China;

关键词: walnut shell powder;    acid mine drainage;    Acidithiobacillus ferrooxidans;    rus operon;   

DOI  :  10.3390/ijerph13050461

来源: DOAJ

【 摘 要 】

Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe2+ or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe2+ oxidization and H+ production were evaluated. Second, the chemical constituents of walnut shell were isolated to determine the active ingredient(s). Third, the expression of Fe2+-oxidizing genes and rus operon genes was investigated using real-time polymerase chain reaction. Finally, growth curves were plotted, and a bioleaching experiment was performed to confirm the active ingredient(s) in walnut shells. The results indicated that both walnut shell powder and the phenolic fraction exert high inhibitory effects on Fe2+ oxidation and H+ production by A. ferrooxidans cultured in standard 9K medium. The phenolic components exert their inhibitory effects by down-regulating the expression of Fe2+-oxidizing genes and rus operon genes, which significantly decreased the growth of A. ferrooxidans. This study revealed walnut shell powder to be a promising substance for controlling AMD.

【 授权许可】

Unknown