Application of acid and heavy metal resistant bacteria from rat-hole coal mines in bioremediation strategy.

Abstract

The Gram-negative bacteria isolated from acid mine drainage (AMD) of rat-hole coal mines were found to be resistant to acidic conditions as well as Fe, Cd, and Cr. The minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) of iron, cadmium, and chromium against the isolates of Enterobacter huaxiensis KHED8 were 4000, 4096, and 256 mg/L, respectively, while the MIC and MBC of Fe, Cd, and Cr against two isolates (KH5M10 and KHCL12) of Serratia marcescens subsp. sakuensis isolates were 4000, 8192, and 256 mg/L, respectively. It was also found that E. huaxiensis KHED8 was able to remove 89%, 90%, and 82.45% of Fe, Cd, and Cr, respectively, and the two isolates of S. marcescens subsp. sakuensis KH5M10 and KHCL12 were able to remove 90%, 95%, and 85.62% of Fe, Cd, and Cr, respectively. The findings of the study provide lead to the use of these heavy metals resistant bacterial isolates for bioremediation of heavy metals laden AMD prevalent in unique rat-hole coal mines.