Correct option is D
Explanation-
"bioaugmentation" — a bioremediation strategy where preselected strains of microbes (often highly efficient at degrading pollutants) are added directly to a contaminated site to speed up the breakdown of pollutants.
1. Microbes are added intentionally (not just stimulated).
2. They can include both archaea and bacteria.
3. The purpose is to enhance biodegradation of pollutants.
Incorrect Options-
Option A - Developing microbial strains through genetic engineering which can degrade pollutants and toxic compounds efficiently
This refers to genetic engineering or synthetic biology, not bioaugmentation. Bioaugmentation uses naturally occurring or pre-isolated microbes, not newly engineered ones.
Option B - Ex-situ bioremediation of toxins from soil or any other contaminant site by addition of selected microbes to enhance biodegradation
Ex-situ = outside the original contaminated site (e.g., in bioreactors or landfarms).
Bioaugmentation is typically in-situ, i.e., done directly at the contaminated site.
Option C - Addition of nutrients at contaminated sites to enhance growth of indigenous microflora which will in turn degrade pollutants
This refers to biostimulation, not bioaugmentation. Biostimulation enhances the activity of indigenous microbes by nutrient addition. Bioaugmentation involves introducing new strains, not just feeding the native ones.
So, the correct option is D -Addition of selected microbes both archaea and bacteria to the polluted site so that biodegradation is enhanced
