Question

Give examples of how bacteria and plants can be used to create a cleaner environment.

Answer 1

Answer:

Plants in Bioremediation:

Plants perform the following bioremediation processes:

1. Phytoextraction
2. Phytodegradation

Bacteria in Bioremediation:

Bacteria are widely used to clean-up pollutants from the following:

1. Wastewater
2. Oil spills
3. Contaminated soil

Explanation:

Bioremediation:

Bioremediation is the process of utilizing biological agents to clean up or re-mediate polluted environments.

Bioremediation Through Plants:

Plants perform different types of bioremediation processes:

Phytoextraction refers to the use of plants to extract or remove contaminants from an environment. This usually involves plants that are hyper-accumulators i.e. plants that have a genetic tendency to accumulate large amounts of a substance such as a nutrient or heavy metal. These plants simply absorb the pollutants from the soil.Following are some examples of plants and the heavy metals they accumulate:

1. Heavy metal bioremediation with Ficus microcarpa.
2. Sunflower or Helianthus annuus is used to extract the heavy metal arsenic from polluted soil. Sunflower has also been used to clear caesium-137 and strontium-90 from ponds in the aftermath of the Chernobyl incident.
3. Alpine pennycress or Thlaspi caerulescens is used to clear the heavy metals cadmium and zinc.
4. Indian mustard or Brassica juncea, ragweed or Ambrosia artemisiifolia, hemp dogbane or Apocynum cannabinum, or poplar trees are used to remove lead from the soil.

Phytodegradation is the process that degrades organic pollutants either in the soil or in the plant body. The plant's roots release enzymes that digest the pollutants. The pollutants can also be taken up by the plant, digested inside the body and then released in a modified form through transpiration.

Bioremediation through Bacteria:

Bacteria in contaminated soil and wastewater metabolize contaminants and transform them, through redox reactions, into energy yielding compounds required by the bacteria.

Oil spills are cleaned-up using two methods:

1. Oil degrading bacteria are used to directly clean-up oil spills.
2. Nutrients essential for the growth of oil degrading bacteria are used.