Optimization of Chromium Removal by the Indigenous Bacterium Bacillus spp. REP02 Using the Response Surface...

Area of Science:

• Environmental Microbiology
• Bioremediation

Background:

• Industrial effluents often contain toxic heavy metals like chromium.
• Chromium contamination poses significant environmental and health risks.
• Bioremediation using indigenous microorganisms offers a sustainable solution.

Purpose of the Study:

• To isolate and identify chromium-removing bacteria from industrial effluents.
• To optimize culture medium parameters for enhanced chromium(II) ion removal by Bacillus REP02.
• To evaluate the efficiency of Bacillus REP02 in Cr(2+) bioremediation.

Main Methods:

• Isolation of Bacillus REP02 from chromium electroplating industrial effluents.
• Application of response surface methodology (RSM) with a Box-Behnken design.
• Optimization of five key medium parameters: K2HPO4, yeast extract, MgSO4, NH4NO3, and dextrose.

Main Results:

• A quadratic response surface model demonstrated high fitness (R²=0.93, F-value=3.92, P<0.0008).
• Optimized conditions led to a predicted 98.86% Cr(2+) removal.
• Experimental validation confirmed a high Cr(2+) removal efficiency of 99.08%.

Conclusions:

• Bacillus REP02 is a potent chromium-removing bacterium.
• Optimized medium composition significantly enhances Cr(2+) bioremediation.
• This study highlights the potential of Bacillus REP02 for industrial wastewater treatment.