**4.5 Bioremediation by microorganisms**

Microorganisms are the beneficial source for removing pollutants from soil and water. Microorganisms remove pollutants from water by passive as well as active approaches as shown in **Figure 5**.

*Recent Applications of Bioremediation and Its Impact DOI: http://dx.doi.org/10.5772/intechopen.104959*

#### **Figure 5.**

*Steps involved in environmental remediation using microorganisms [22].*


#### **4.6 Bioremediation by nematodes**

Nematode parasites are a sensitive indicator of heavy metals in the aquatic ecosystem showing sharing of more burden of environmental pollution of the sea and also act as bioremediator of heavy metals in fish. In rhizosphere, they are involved in cleaning, nutrient mobilization, nitrification, enzyme activation, etc.

For heavy metal removals, nematodes are being used.

