(Jeschke 2016). There are evidences to demonstrate that the routine application of
insecticides and fungicides have little or no significant increase in today’s crop yields
(Lechenet et al. 2017). The solution to this problem, therefore, is not to add new
chemicals to the already saturated pesticide market but to find different ways of
combating this war against weeds and pests (Owen et al. 2015; Chauhan et al. 2017;
Phour and Sindhu 2019), without affecting the ecosystem resources and services
provided by soil biota and pollinators, which are essential for agricultural productivity (van Hoesel et al. 2017).
Two types of GM crops have been developed, one for pest control (i.e., Bt-crops)
and the other for herbicide resistance (glyphosate-GM crops). Bt-crops produce the
toxin of Bacillus thuringiensis, which are very effective against caterpillars and
grubs (Hutchison 1999) without damaging natural enemies of the pests (Thomazoni
et al. 2010), thus avoiding the use of insecticide sprays against such pests (Wadhwa
and Gill 2007); however, this has created secondary pests that require the use of
other insecticides. By contrast, glyphosate-GM crops are resistant against this
herbicide, so the farmers can apply glyphosate products without harming the crop
plants. Unfortunately, this has led to an overuse of the herbicides that fostered rapid
development of resistance among various weeds plus contamination of the environment (Powles 2008; Beckie and Hall 2014; Sindhu and Sehrawat 2017).
2.11 Conclusion
Bioremediation has tremendous potential for the remediation of contaminated soils
infested with pesticides. Rhizosphere microorganisms play an important role in the
degradation of various pesticide residues. A consortium of microorganisms thrives,
which degrades pesticide contaminants into a simple chemical compound that may
be used by the crop plant and reduce the use of chemical pesticides in agriculture.
The continuous degradation of chemicals by enzymatic reactions represents the most
important strategy with high bioremediation efficiency. These biocatalysts may be
formed in large numbers by genetic engineering technology, expression of enzymes,
or indigenous organisms that are used in agriculture to remove pesticides from
contaminated sites. Further research on the biodegradation or biotransformation
mechanisms in plants, bacteria, fungi, or algae is essential to improve bioremediation
strategies. An in-depth study of the microorganisms is needed to excavate the
pesticide degradation process and the mechanisms by which their enzymes are used.
References
Abdullah RR, Ghani SBA, Sukar NA (2016) Degradation of profenofos and λ-cyhalothrin using
endogenous bacterial isolates and detection of the responsible genes. J Bioremed Biodegr 7:360.
https://doi.org/10.1007/978-981-13-1891-7_13
2 Bioremediation of Pesticides: An Eco-Friendly Approach for Environment. . .
61
insecticides and fungicides have little or no significant increase in today’s crop yields
(Lechenet et al. 2017). The solution to this problem, therefore, is not to add new
chemicals to the already saturated pesticide market but to find different ways of
combating this war against weeds and pests (Owen et al. 2015; Chauhan et al. 2017;
Phour and Sindhu 2019), without affecting the ecosystem resources and services
provided by soil biota and pollinators, which are essential for agricultural productivity (van Hoesel et al. 2017).
Two types of GM crops have been developed, one for pest control (i.e., Bt-crops)
and the other for herbicide resistance (glyphosate-GM crops). Bt-crops produce the
toxin of Bacillus thuringiensis, which are very effective against caterpillars and
grubs (Hutchison 1999) without damaging natural enemies of the pests (Thomazoni
et al. 2010), thus avoiding the use of insecticide sprays against such pests (Wadhwa
and Gill 2007); however, this has created secondary pests that require the use of
other insecticides. By contrast, glyphosate-GM crops are resistant against this
herbicide, so the farmers can apply glyphosate products without harming the crop
plants. Unfortunately, this has led to an overuse of the herbicides that fostered rapid
development of resistance among various weeds plus contamination of the environment (Powles 2008; Beckie and Hall 2014; Sindhu and Sehrawat 2017).
2.11 Conclusion
Bioremediation has tremendous potential for the remediation of contaminated soils
infested with pesticides. Rhizosphere microorganisms play an important role in the
degradation of various pesticide residues. A consortium of microorganisms thrives,
which degrades pesticide contaminants into a simple chemical compound that may
be used by the crop plant and reduce the use of chemical pesticides in agriculture.
The continuous degradation of chemicals by enzymatic reactions represents the most
important strategy with high bioremediation efficiency. These biocatalysts may be
formed in large numbers by genetic engineering technology, expression of enzymes,
or indigenous organisms that are used in agriculture to remove pesticides from
contaminated sites. Further research on the biodegradation or biotransformation
mechanisms in plants, bacteria, fungi, or algae is essential to improve bioremediation
strategies. An in-depth study of the microorganisms is needed to excavate the
pesticide degradation process and the mechanisms by which their enzymes are used.
References
Abdullah RR, Ghani SBA, Sukar NA (2016) Degradation of profenofos and λ-cyhalothrin using
endogenous bacterial isolates and detection of the responsible genes. J Bioremed Biodegr 7:360.
https://doi.org/10.1007/978-981-13-1891-7_13
2 Bioremediation of Pesticides: An Eco-Friendly Approach for Environment. . .
61