6.4 Bioremediation

85

hydrocarbons in the tissues. Moreover, mercury is identified to display antagonistic

effects [21] such as deterioration in the nervous system, impaired vision, gait,

hearing and speech, leading to involuntary muscle actions and deterioration of

mucosa and skin. Consumption of plants or aquatic animals with heavy metals

and toxic substances is a major reason for the consequences of different kinds of

cancers, respiratory illnesses, kidney failure, brain impairment, heart diseases, and

birth defects [22]. The addition of metals in the tissues of aquatic organisms will

have an ill effect on their growth and reproduction.

Accumulation of material that leads to biomagnification can interrupt the usual

food chain that is vital for the existence of all categories of animals in the ecosystem.

This may have a long-lasting consequence which might not be observed in short

period [23, 24]. India reported its first case of poisoning owing to pesticides from

Kerala in 1958. Over 100 people died subsequently after the intake of wheat flour

which was contaminated with parathion, a pesticide [11].

Also, production workers, sprayers, formulators, loaders, mixers, and farm work-

ers are at major risk of diseases due to maximum pesticide exposure. Throughout

the formulation and manufacture, workers are at amplified risk as they manage

numerous toxic chemicals to produce pesticides which include toxic solvents, raw

materials, and inert carriers [11].

6.4

Bioremediation

Bioremediation is the process where genetically modified or naturally occurring

microorganisms or plants [19] are used to degrade hazardous molecules from eco-

logical samples including water and soil. Hence, the bioremediation process plays an

important role as an eco-friendly procedure. Pesticides are involved in the destruc-

tion of the typical features of soil and also spread into the water, thus damaging the

marine environment. Hence, they have to be decontaminated off the polluted areas.

Bioremediation can be performed by two methodologies, “in situ” and “ex situ.” To

endure microbial activity when the climate is too cold or the soil is too compressed

for the nutrients to dispense, requirement of ex situ is most recommended. However,

ex situ is cost-consuming as the process requires clearing of the soil on the ground

and exhuming. Microbes exploit the contaminants which include solvents, oil, and

pesticides as their source of energy. Process of utilization of these contaminants leads

to water and harmless gases like carbon dioxide. However, if the conditions like tem-

perature and nutrients are not supportive enough, the bioremediation facilitation

will slow down. Hence, to improve the process substances like molasses, vegetable

oil can be added as amendments and fasten the cleanup. The added substances aid in

optimization for microbes to thrive in the surroundings and thus gear up the process

of bioremediation [19].

The Burkholderia, Pseudomonas, Azotobacter, Flavobacterium, and Arthobacter

are the bacterial strains that aid in degradation of pesticides. When the in-house

microbes cannot involve successfully in the degradation of pesticide, additional

strains of bacteria or fungi need to be provided to facilitate the degradation.

Favorable conditions like pH, temperature, nutrients, and enzymes are of much